Quick cards

NCLEX Drug Classes

One card per class: prototypes, the check before giving, teaching, antidotes and the traps

Reviewed by Alex G, BSN, RN, CEN, CCRN, CMC, NREMT-P · From the Reference tab of the app

Beta blockers (-olol)

Hypertension, angina, heart failure, rate control

Prototypes	Metoprolol, atenolol (β₁-selective); propranolol (nonselective); carvedilol, labetalol (β plus α₁)
Use	Hypertension, angina, heart failure with reduced EF (metoprolol succinate, carvedilol), rate control
How it works	Block β₁ receptors: slower heart rate, less contractility, lower BP
Key adverse effects	Bradycardia, heart block, hypotension, fatigue, dizziness, depression; bronchospasm; heart failure can worsen while the dose is raised
Assess before giving	Apical pulse and BP. Hold and report a pulse under 60 or a low BP unless the order says otherwise
Teaching	Check pulse before each dose; never stop suddenly (angina, MI); carvedilol with food to limit orthostasis; report weight gain or swelling
Antidote and interactions	Blunt albuterol and can trigger severe bronchospasm in asthma; IV diltiazem and IV beta blockers are not given together
NCLEX traps	Masks hypoglycemia warning signs such as tachycardia; avoid in bronchospastic disease (nonselective agents especially); taper over 1–2 weeks

ACE inhibitors (-pril) and ARBs (-sartan)

Hypertension, heart failure, after MI

Prototypes	Lisinopril, enalapril, captopril (ACE inhibitors); losartan, valsartan (ARBs)
Use	Hypertension; heart failure and acute MI (lisinopril)
How it works	ACE inhibitors stop angiotensin II forming; ARBs block its receptor: vasodilation and less aldosterone
Key adverse effects	Dry cough (ACE inhibitors), angioedema, hypotension in the first days, hyperkalemia, rising creatinine
Assess before giving	BP, K⁺ and creatinine; any history of angioedema (contraindicated)
Teaching	Report swelling of the face, lips, tongue or throat at once; report lightheadedness early on; no potassium supplements or salt substitutes unless prescribed
Antidote and interactions	Raise lithium levels; NSAIDs blunt the effect and harm the kidneys; K⁺ supplements and spironolactone add hyperkalemia; no aliskiren in diabetes
NCLEX traps	Boxed: stop as soon as pregnancy is found (fetal injury). Angioedema is more common in Black patients on ACE inhibitors. Losartan caused far less cough than lisinopril in its label trials. 36 h gap to or from sacubitril/valsartan

Calcium channel blockers (-dipine, diltiazem, verapamil)

Hypertension, angina, AF rate control, PSVT

Prototypes	Amlodipine, nifedipine (dihydropyridines, act on vessels); diltiazem, verapamil (also slow the AV node)
Use	Hypertension and stable angina (amlodipine); AF or flutter rate control and PSVT (IV diltiazem)
How it works	Block calcium entry into vascular and cardiac muscle: vasodilation; diltiazem and verapamil slow AV conduction
Key adverse effects	Ankle edema (amlodipine 10 mg: 10.8% vs 0.6% placebo), flushing, dizziness, palpitations; diltiazem: hypotension, bradycardia, AV block
Assess before giving	BP; apical pulse and rhythm before diltiazem or verapamil
Teaching	Rise slowly; report ankle swelling, dizziness or a slow pulse; angina can briefly worsen when starting or raising amlodipine
Antidote and interactions	Amlodipine caps simvastatin at 20 mg; CYP3A4 inhibitors raise amlodipine; grapefruit juice does not change amlodipine exposure (label)
NCLEX traps	IV diltiazem is contraindicated in AF or flutter with WPW, 2nd or 3rd degree block or sick sinus without a pacemaker, severe hypotension, shock and VT

Digoxin (cardiac glycoside)

Heart failure and AF rate control

Prototypes	Digoxin (Lanoxin)
Use	Mild to moderate heart failure; ventricular rate control in chronic AF
How it works	Inhibits Na⁺/K⁺-ATPase: stronger contraction, slower AV conduction
Key adverse effects	Toxicity: anorexia, nausea, vomiting, fatigue, color-vision changes, any new arrhythmia
Assess before giving	Apical pulse for 1 full minute: hold and report under 60. K⁺ and digoxin level
Teaching	Take and record the pulse daily; report nausea, vision changes or a slow or irregular pulse
Antidote and interactions	Digoxin immune fab (DigiFab) for toxicity. Amiodarone (about 70%) and verapamil (50–75%) raise levels: cut digoxin 30–50%
NCLEX traps	Low K⁺, low Mg²⁺ and high Ca²⁺ invite toxicity (watch loop and thiazide diuretics). Levels over 2 ng/mL add toxicity without benefit; under 0.5 lose effect

Nitrates (nitroglycerin, isosorbide)

Angina relief and prevention

Prototypes	Nitroglycerin (SL tablet, spray, patch, IV); isosorbide mononitrate
Use	Acute angina and prevention before exertion
How it works	Dilate veins more than arteries: less preload and myocardial oxygen demand
Key adverse effects	Headache (dose-related, early in therapy), hypotension especially standing, dizziness; tolerance with excessive use
Assess before giving	BP before each dose; chest pain rating
Teaching	1 SL tablet at the first sign of pain, sitting down; repeat every 5 min, no more than 3 in 15 min; get emergency care if pain persists or differs from usual. Keep in the original glass bottle, capped tightly
Antidote and interactions	Contraindicated with PDE-5 inhibitors (sildenafil, tadalafil) and riociguat: severe hypotension
NCLEX traps	Contraindicated in raised ICP, severe anemia, acute circulatory failure and shock. Headache is expected, not a reason to stop

Antiarrhythmics: amiodarone and adenosine

Life-threatening ventricular rhythms and PSVT

Prototypes	Amiodarone (class III); adenosine
Use	Amiodarone: recurrent life-threatening VF and hemodynamically unstable VT. Adenosine: converts PSVT to sinus rhythm
How it works	Amiodarone prolongs repolarization; adenosine briefly blocks the AV node (half-life under 10 s)
Key adverse effects	Amiodarone: lung toxicity (fatal in about 10% of cases), liver injury, hypo- or hyperthyroidism, bradycardia, optic neuropathy, photosensitivity, blue-gray skin. Adenosine: flushing, dyspnea, chest pressure, brief asystole
Assess before giving	Continuous ECG with IV doses. Amiodarone: baseline chest X-ray, PFTs, LFTs, thyroid tests, eye exam
Teaching	Report cough or breathlessness, vision changes, a slow pulse; sunscreen; no grapefruit juice or St John’s wort with amiodarone
Antidote and interactions	Amiodarone: cut warfarin by ⅓ to ½ and halve digoxin. Adenosine: dipyridamole potentiates it; caffeine and theophylline blunt it
NCLEX traps	Adenosine is 6 mg rapid IV push over 1–2 s with a fast saline flush, then 12 mg; avoid in asthma (bronchospasm)

Statins (-statin)

Lower LDL and cardiovascular risk

Prototypes	Atorvastatin, simvastatin, rosuvastatin
Use	High LDL; lower the risk of MI and stroke
How it works	Block HMG-CoA reductase, the liver’s cholesterol-making enzyme
Key adverse effects	Muscle pain, myopathy, rarely rhabdomyolysis; raised liver enzymes; small rise in A1C and glucose
Assess before giving	Lipid panel; liver enzymes before starting; ask about muscle pain or weakness
Teaching	Report unexplained muscle pain, tenderness or weakness promptly; simvastatin in the evening, atorvastatin any time; diet and exercise still matter
Antidote and interactions	Simvastatin: strong CYP3A4 inhibitors, gemfibrozil, cyclosporine contraindicated; max 10 mg with diltiazem or verapamil, 20 mg with amlodipine or amiodarone. Atorvastatin: no more than 1.2 L grapefruit juice a day
NCLEX traps	Stop when pregnancy is recognized; no breastfeeding; contraindicated in acute liver failure or decompensated cirrhosis; avoid grapefruit juice with simvastatin

Heparin and low-molecular-weight heparin (-parin)

DVT and PE prevention and treatment, ACS

Prototypes	Heparin (unfractionated); enoxaparin (LMWH)
Use	Prevent and treat DVT and PE; unstable angina and MI; heparin also for AF clots, DIC, dialysis and bypass circuits
How it works	Boost antithrombin to block thrombin and factor Xa (enoxaparin acts mostly on Xa)
Key adverse effects	Bleeding; HIT (falling platelets with new clots); injection-site bruising; spinal or epidural hematoma with neuraxial anesthesia (enoxaparin, boxed)
Assess before giving	Heparin: aPTT (therapeutic 1.5–2 times normal), platelets, hematocrit, stool occult blood. Enoxaparin: CBC with platelets, CrCl (dose change under 30)
Teaching	Enoxaparin deep SC into the abdominal wall, alternating sides; keep the air bubble in a prefilled syringe; do not rub the site; report bleeding or black stools
Antidote and interactions	Protamine: 1 mg per about 100 units of heparin (no more than 50 mg in 10 min); 1 mg per 1 mg enoxaparin given within 8 h, which neutralizes at most about 60%
NCLEX traps	Check vial strength (fatal mix-ups); never IM; stop heparin for platelets under 100,000 or a new clot; enoxaparin is not interchangeable unit for unit, and aPTT does not monitor it

Warfarin (vitamin K antagonist)

Long-term anticoagulation monitored by INR

Prototypes	Warfarin (Jantoven)
Use	Prevent and treat DVT and PE; AF and valve clots; after MI
How it works	Blocks vitamin K–dependent clotting factors; no effect on a clot already formed
Key adverse effects	Bleeding (boxed), skin necrosis, purple toes syndrome; fetal harm
Assess before giving	INR: 2–3 for most uses, 2.5–3.5 for mechanical mitral valves; signs of bleeding
Teaching	Keep vitamin K intake steady (leafy greens) rather than avoiding it; regular INR checks; report bleeding; tell dentists; ask before any new drug, herb or supplement
Antidote and interactions	Vitamin K₁ (phytonadione) takes at least 1–2 h to improve the PT; PCC or plasma for urgent bleeding. NSAIDs, aspirin, SSRIs, garlic and ginkgo add bleeding; St John’s wort weakens it; antibiotics and amiodarone change INR
NCLEX traps	Peak effect takes 72–96 h, so heparin overlaps for 4–5 days until the INR is therapeutic; INR over 4 adds bleeding without benefit; contraindicated in pregnancy except some mechanical valves

Direct oral anticoagulants (-xaban, dabigatran)

AF stroke prevention, DVT and PE

Prototypes	Apixaban, rivaroxaban (factor Xa inhibitors); dabigatran (direct thrombin inhibitor)
Use	Stroke prevention in nonvalvular AF; treat and prevent DVT and PE
How it works	Directly block factor Xa or thrombin; no INR monitoring
Key adverse effects	Bleeding; spinal or epidural hematoma with neuraxial procedures (boxed); dabigatran: dyspepsia and GI upset
Assess before giving	Kidney function and bleeding. Apixaban drops to 2.5 mg twice daily with 2 of: age 80 or more, weight 60 kg or less, creatinine 1.5 or more
Teaching	Do not stop early (boxed: clots); missed apixaban: take it the same day, never double; rivaroxaban 15 and 20 mg with the evening meal for AF
Antidote and interactions	Dabigatran: idarucizumab. Apixaban and rivaroxaban: US andexanet sales ended December 2025, so follow the hospital bleeding protocol. Strong CYP3A4 and P-gp inhibitors raise levels
NCLEX traps	Not studied in prosthetic valves (apixaban); not recommended in triple-positive antiphospholipid syndrome; avoid rivaroxaban for DVT or PE at CrCl under 15

Antiplatelets: aspirin and P2Y₁₂ inhibitors (-grel)

ACS, stents, recent MI or stroke, PAD

Prototypes	Aspirin; clopidogrel
Use	ACS (clopidogrel with aspirin), recent MI or stroke, peripheral artery disease
How it works	Clopidogrel irreversibly blocks the platelet P2Y₁₂ ADP receptor for the platelet’s 7–10 day life; aspirin irreversibly blocks platelet COX
Key adverse effects	Bleeding (most common), GI bleeding; clopidogrel: TTP (rare, can follow under 2 weeks); aspirin: ringing in the ears
Assess before giving	Bleeding signs, platelets, any planned procedure
Teaching	Do not stop without the prescriber; tell dentists and surgeons; report unusual bleeding; stop aspirin and call if the ears ring
Antidote and interactions	Avoid omeprazole and esomeprazole with clopidogrel (less effect); NSAIDs, warfarin, SSRIs and SNRIs add bleeding; ibuprofen can blunt aspirin’s antiplatelet effect
NCLEX traps	Clopidogrel is held about 5 days before surgery when possible; poor CYP2C19 metabolizers get less effect (boxed); no aspirin for children or teens with chickenpox or flu-like illness (Reye)

Thrombolytics (-teplase)

Acute ischemic stroke, MI, massive PE

Prototypes	Alteplase (tPA)
Use	Acute ischemic stroke; also MI and massive PE; Cathflo restores blocked central lines
How it works	Converts plasminogen to plasmin, which dissolves fibrin
Key adverse effects	Bleeding, including intracranial; angioedema during and up to 2 h after the infusion
Assess before giving	No intracranial or subarachnoid hemorrhage. BP under 185/110 before and under 180/105 for 24 h after (AHA)
Teaching	Stroke dose 0.9 mg/kg (max 90 mg): 10% as a 1-min bolus, the rest over 60 min; no IM injections or new noncompressible punctures; compress any arterial stick at least 30 min
Antidote and interactions	Angioedema is more common with ACE inhibitors; anticoagulants and antiplatelets add bleeding
NCLEX traps	Label stroke window is 3 h from onset; AHA guidance extends it to 4.5 h. Contraindicated after intracranial surgery or serious head trauma within 3 months, with bleeding diathesis or severe uncontrolled hypertension

Loop (-semide, -anide) and thiazide (-thiazide) diuretics

Edema and hypertension

Prototypes	Furosemide, bumetanide (loop); hydrochlorothiazide, chlorthalidone (thiazide)
Use	Loop: edema in heart failure, cirrhosis and kidney disease; hypertension. Thiazide: hypertension, milder edema
How it works	Loop: block Na⁺-K⁺-2Cl⁻ reabsorption in the loop of Henle (strong). Thiazide: block sodium reabsorption in the distal tubule
Key adverse effects	Hypokalemia, hyponatremia, dehydration, orthostatic hypotension, high glucose, high uric acid and gout. Loop: ototoxicity. Thiazide: high calcium, lipids, angle-closure glaucoma
Assess before giving	K⁺, Na⁺, BUN, creatinine, BP, daily weight, intake and output
Teaching	Stand up slowly; weigh daily; report weakness, dizziness or eye pain; sunscreen and skin checks (HCTZ)
Antidote and interactions	Raise lithium levels; low K⁺ worsens digoxin toxicity; furosemide adds aminoglycoside ototoxicity; NSAIDs blunt the effect
NCLEX traps	IV furosemide slowly over 1–2 min (high doses no faster than 4 mg/min); onset within 5 min, lasts about 2 h. Sulfonamide allergy may cross-react. Thiazides are contraindicated in anuria

Potassium-sparing diuretics (spironolactone)

Heart failure, hyperaldosteronism, cirrhosis edema

Prototypes	Spironolactone, eplerenone; triamterene, amiloride
Use	Heart failure with reduced EF (survival), add-on for hypertension, cirrhosis edema, primary hyperaldosteronism
How it works	Spironolactone blocks aldosterone in the distal tubule: loses sodium, keeps potassium
Key adverse effects	Hyperkalemia; gynecomastia (most common)
Assess before giving	K⁺ within 1 week of starting or a dose change, then regularly; kidney function
Teaching	No potassium supplements or salt substitutes (KCl) unless prescribed; report muscle weakness or palpitations
Antidote and interactions	ACE inhibitors, ARBs, K⁺ supplements and trimethoprim add hyperkalemia; spironolactone with eplerenone is contraindicated
NCLEX traps	Contraindicated in hyperkalemia and Addison disease; oral KCl with triamterene or amiloride is contraindicated

Bronchodilators: β₂ agonists (-terol) and anticholinergics (-tropium)

Rescue and maintenance in asthma and COPD

Prototypes	Albuterol (SABA, rescue); salmeterol (LABA); ipratropium (short-acting), tiotropium (long-acting anticholinergic)
Use	Albuterol: acute bronchospasm and before exercise. Salmeterol and tiotropium: maintenance (salmeterol in asthma only with an ICS; tiotropium for COPD)
How it works	β₂ agonists relax airway smooth muscle; anticholinergics block muscarinic bronchoconstriction
Key adverse effects	Albuterol: tachycardia, tremor, nervousness, low K⁺, paradoxical bronchospasm. Tiotropium: dry mouth, urinary retention, worse narrow-angle glaucoma
Assess before giving	Breath sounds, work of breathing, SpO₂, heart rate
Teaching	Albuterol 2 puffs every 4–6 h; needing it more often means asthma is worsening. Prime a new inhaler with 4 sprays; wash the actuator weekly. Spiriva capsules are inhaled, never swallowed; keep powder out of the eyes
Antidote and interactions	Beta blockers block albuterol and can cause severe bronchospasm; no second LABA alongside salmeterol
NCLEX traps	LABA alone in asthma is contraindicated (boxed: asthma deaths); salmeterol and tiotropium are never rescue drugs

Asthma controllers: inhaled steroids (-sone, -nide) and montelukast (-lukast)

Daily maintenance, not rescue

Prototypes	Fluticasone, budesonide (ICS); montelukast (leukotriene receptor antagonist)
Use	Daily asthma maintenance; montelukast also allergic rhinitis
How it works	ICS calm airway inflammation; montelukast blocks the CysLT₁ leukotriene receptor
Key adverse effects	ICS: oral thrush, throat irritation, slower growth in children, adrenal insufficiency when switched from oral steroids. Montelukast: neuropsychiatric events including suicidal thoughts (boxed)
Assess before giving	Asthma control and how often the rescue inhaler is used; growth in children; mood and behavior on montelukast
Teaching	Rinse the mouth with water and spit after each ICS dose; full benefit can take 1–2 weeks or longer; take daily even when well; montelukast once in the evening
Antidote and interactions	Switching from oral steroids to an ICS: adrenal insufficiency deaths have occurred, so taper slowly under supervision
NCLEX traps	Neither treats an acute attack. Montelukast for allergic rhinitis is reserved for patients who cannot use other treatments (boxed)

Insulins (by onset, peak and duration)

Rapid, short, intermediate and long acting

Prototypes	Rapid: lispro, aspart. Short: regular. Intermediate: NPH. Long: glargine, degludec
Use	Type 1 diabetes (basal plus mealtime), type 2 when needed; IV regular insulin only under close supervision
How it works	Onset / peak / duration (FDA 2026): rapid within 15 min / 1–2 h / 3–5 h; regular 30–60 min / 2–4 h / 5–8 h; NPH 1–3 h / 4–12 h / 12–18 h; long-acting no pronounced peak, about 20–24 h
Key adverse effects	Hypoglycemia (most common), hypokalemia, lipodystrophy and reactions at the injection site
Assess before giving	Blood glucose and the meal: is food coming? K⁺ with IV insulin
Teaching	Lispro within 15 min before or right after a meal; regular about 30 min before; peaks are the hypoglycemia danger times; rotate sites within one region; never share pens
Antidote and interactions	Glucose under 70 mg/dL and awake: 15 g glucose, recheck in 15 min, repeat if still low; glucagon if unable to swallow (ADA 2026). Beta blockers mask warning signs
NCLEX traps	Draw regular or lispro before NPH (clear before cloudy); only NPH mixes with them; roll and invert NPH to mix; glargine is never mixed, diluted or given IV

Non-insulin diabetes drugs (metformin, -gliflozin, -glutide, -gliptin, sulfonylureas)

Type 2 diabetes

Prototypes	Metformin; glipizide (sulfonylurea); empagliflozin (SGLT2); semaglutide (GLP-1 RA); sitagliptin (DPP-4)
Use	Type 2 diabetes. ADA 2026: an SGLT2 inhibitor or GLP-1 RA with proven benefit for ASCVD, heart failure or CKD regardless of A1C
How it works	Metformin lowers liver glucose output; sulfonylureas release insulin; SGLT2 inhibitors spill glucose into urine; GLP-1 RAs and DPP-4 inhibitors boost glucose-dependent insulin
Key adverse effects	Metformin: diarrhea, nausea, B₁₂ deficiency, rare lactic acidosis (boxed). Sulfonylureas: hypoglycemia. SGLT2: genital yeast infection, UTI, volume loss, ketoacidosis even with glucose under 250, Fournier gangrene. GLP-1: nausea, vomiting, pancreatitis, gallbladder disease
Assess before giving	Glucose and A1C; eGFR (metformin contraindicated under 30, not started at 30–45)
Teaching	Metformin with meals; glipizide XL with breakfast; semaglutide shot once weekly on the same day (missed: give within 5 days); report severe abdominal pain
Antidote and interactions	Hold metformin at or before iodinated contrast when eGFR is 30–60 and recheck eGFR at 48 h; stop an SGLT2 inhibitor at least 3 days before surgery; insulin or sulfonylureas with any of these raise hypoglycemia; tell anesthesia about GLP-1 RAs (aspiration)
NCLEX traps	GLP-1 RAs are contraindicated with a personal or family history of medullary thyroid cancer or MEN 2 (boxed); metformin’s hypoglycemia risk comes with insulin or a secretagogue; avoid heavy alcohol on metformin

Thyroid drugs: levothyroxine and antithyroid drugs (-azole, PTU)

Hypothyroidism and hyperthyroidism

Prototypes	Levothyroxine (replacement); methimazole, propylthiouracil (antithyroid)
Use	Levothyroxine: hypothyroidism, usually for life. Methimazole, PTU: hyperthyroidism
How it works	Levothyroxine is synthetic T₄; methimazole and PTU block thyroid hormone synthesis
Key adverse effects	Too much levothyroxine looks like hyperthyroidism: tachycardia, arrhythmias, angina, bone loss. Antithyroid drugs: agranulocytosis, liver injury (worse with PTU), vasculitis, hypothyroidism
Assess before giving	Heart rate; TSH (recheck 6–8 weeks after a levothyroxine change); CBC if fever or sore throat on antithyroid drugs
Teaching	Levothyroxine on an empty stomach 30–60 min before breakfast, 4 h apart from calcium, iron and antacids; peak effect in 4–6 weeks. Antithyroid drugs: report sore throat or fever at once
Antidote and interactions	Levothyroxine strengthens warfarin and can weaken digoxin; methimazole can strengthen warfarin
NCLEX traps	Levothyroxine is not for weight loss (boxed); start low in older or cardiac patients; needs often rise in pregnancy. PTU is preferred just before and during the first trimester, methimazole after (liver risk)

Systemic corticosteroids (-sone, -solone)

Inflammation, autoimmune flares, adrenal replacement

Prototypes	Prednisone, methylprednisolone, hydrocortisone, dexamethasone
Use	Inflammatory and autoimmune flares, asthma and COPD exacerbations, allergic reactions, adrenal insufficiency
How it works	Suppress inflammation and the immune response
Key adverse effects	High glucose, infection (signs masked), sodium and fluid retention, hypertension, low K⁺, osteoporosis, peptic ulcer, mood changes or psychosis, Cushingoid features, slowed growth in children
Assess before giving	Glucose, BP, K⁺, weight, signs of infection
Teaching	Never stop suddenly after long use: taper; report infection early; extra doses may be needed for stress such as surgery
Antidote and interactions	Avoid live vaccines on immunosuppressive doses; diabetics need more insulin or oral agents
NCLEX traps	A patient on long-term steroids who stops abruptly or faces major stress risks adrenal insufficiency; steroids hide infection

Acid suppressants: PPIs (-prazole) and H₂ blockers (-tidine)

GERD, ulcers, GI bleed prevention

Prototypes	Pantoprazole, omeprazole (PPIs); famotidine (H₂ blocker)
Use	GERD, erosive esophagitis, peptic ulcer
How it works	PPIs block the parietal cell proton pump (H⁺/K⁺-ATPase); H₂ blockers block histamine-2 receptors
Key adverse effects	PPIs long term: C. difficile diarrhea, hip, wrist and spine fractures, low Mg²⁺, B₁₂ deficiency, interstitial nephritis, lupus. Famotidine: confusion or delirium and QT prolongation in older or kidney patients
Assess before giving	Epigastric pain, stool for blood; Mg²⁺ on long-term PPIs; kidney function (famotidine dose cut at CrCl under 60)
Teaching	Swallow pantoprazole tablets whole, no splitting, crushing or chewing; report diarrhea that does not stop
Antidote and interactions	Omeprazole and esomeprazole weaken clopidogrel; PPIs reduce absorption of iron and some azoles and HIV drugs; rilpivirine contraindicated; may raise methotrexate and INR
NCLEX traps	Persistent diarrhea on a PPI: think C. difficile. Long-term PPI: low Mg²⁺ can need replacement, so check it

Antiemetics: ondansetron (-setron), metoclopramide, promethazine

Nausea and vomiting, gastroparesis

Prototypes	Ondansetron (5-HT₃ blocker); metoclopramide (dopamine blocker, prokinetic); promethazine (phenothiazine)
Use	Chemotherapy and postoperative nausea (ondansetron); diabetic gastroparesis and reflux (metoclopramide)
How it works	Block serotonin (5-HT₃) or dopamine (D₂) signals; metoclopramide also speeds gastric emptying
Key adverse effects	Ondansetron: headache, constipation or diarrhea, QT prolongation, serotonin syndrome. Metoclopramide: tardive dyskinesia (boxed), EPS, akathisia, NMS, depression. Promethazine: sedation, severe tissue injury
Assess before giving	QT and ECG when K⁺ or Mg²⁺ is low (ondansetron); bowel sounds (ondansetron can mask ileus); abnormal movements on metoclopramide
Teaching	Metoclopramide 30 min before meals and at bedtime, no longer than 12 weeks; report restlessness or involuntary movements
Antidote and interactions	Avoid ondansetron in congenital long QT; no metoclopramide with antipsychotics (EPS); serotonergic drugs add serotonin syndrome
NCLEX traps	Promethazine: never under age 2 (fatal respiratory depression), never intra-arterial or SC; deep IM preferred; IV only at 1 mg/mL or less in a large vein. Metoclopramide is contraindicated in GI obstruction, bleeding or perforation, pheochromocytoma and seizures

Bowel drugs: lactulose, laxatives and loperamide

Hepatic encephalopathy, constipation, diarrhea

Prototypes	Lactulose; senna, docusate; loperamide
Use	Lactulose: portal-systemic (hepatic) encephalopathy. Senna, docusate: opioid constipation. Loperamide: diarrhea
How it works	Lactulose acidifies the colon and traps ammonia as ammonium; loperamide slows gut motility
Key adverse effects	Lactulose: gas, cramps, diarrhea; overdosing causes fluid loss, low K⁺ and high Na⁺. Loperamide above the label dose: serious heart problems or death
Assess before giving	Lactulose: mental status, stool count, K⁺ and Na⁺. Loperamide: blood in stool, fever
Teaching	Lactulose goal: 2–3 soft stools a day; in coma it can be a retention enema. Loperamide: stop and call if diarrhea lasts over 2 days
Antidote and interactions	Patients on opioids usually need a laxative such as senna or docusate along with fluids and fiber
NCLEX traps	Lactulose is dosed to stools, so watery diarrhea is the overdose to catch; it contains galactose and lactose (caution in diabetes). No loperamide with bloody or black stool

Opioid analgesics and naloxone

Moderate to severe pain, overdose reversal

Prototypes	Morphine, hydromorphone, oxycodone, fentanyl; reversal: naloxone
Use	Moderate to severe pain; fentanyl patch only for chronic pain in opioid-tolerant patients
How it works	Activate mu opioid receptors in the brain and spinal cord
Key adverse effects	Respiratory depression, sedation, hypotension, nausea, vomiting, constipation, urinary retention, itching; addiction; adrenal insufficiency with long use
Assess before giving	Respirations and sedation level before each dose (report slow or shallow breathing); pain before and after; bowel function
Teaching	Prevent constipation (fluids, fiber, a laxative); no alcohol or sedatives; keep heat (heating pads, hot baths, fever) off a fentanyl patch; fold used patches sticky sides together and flush
Antidote and interactions	Naloxone 0.4–2 mg IV, repeat every 2–3 min for overdose; 0.1–0.2 mg steps after surgery; it can wear off before the opioid, so watch for re-sedation. Benzodiazepines and other CNS depressants add fatal respiratory depression (boxed)
NCLEX traps	IV morphine’s peak CNS effect lags about 30 min, so fast pushes overdose; fentanyl patch is worn up to 72 h, never for acute or postoperative pain, and one patch can kill a child; full abrupt reversal brings withdrawal, pulmonary edema, VF

Acetaminophen and NSAIDs (-profen, ketorolac)

Pain, fever, inflammation

Prototypes	Acetaminophen; ibuprofen, naproxen, ketorolac
Use	Pain and fever; NSAIDs also inflammation
How it works	NSAIDs block COX and prostaglandin synthesis; acetaminophen acts centrally with little anti-inflammatory effect
Key adverse effects	Acetaminophen: liver failure in overdose, rare serious skin reactions. NSAIDs: GI bleeding and ulcers, MI and stroke (boxed), kidney injury, fluid retention
Assess before giving	Total acetaminophen from every product; alcohol use, malnutrition or liver disease. NSAIDs: kidney function, bleeding history, BP
Teaching	Acetaminophen max 4 g a day for adults 50 kg or more, counting combination products; NSAIDs with food or milk if the stomach is upset; report black stools
Antidote and interactions	Acetaminophen overdose: acetylcysteine (NAC) as early as possible. NSAIDs blunt ACE inhibitors, ARBs and diuretics, raise lithium, add GI bleeding with warfarin, and ibuprofen can blunt aspirin’s cardioprotection
NCLEX traps	Ketorolac: 5 days total, IV plus oral, lower doses at 65 or older or under 50 kg; no NSAIDs around CABG; avoid NSAIDs from about 30 weeks of pregnancy (oligohydramnios risk from about 20 weeks)

Penicillins (-cillin) and cephalosporins (cef-, ceph-)

Beta-lactam antibiotics

Prototypes	Amoxicillin, piperacillin-tazobactam; cephalexin, cefazolin, ceftriaxone
Use	Respiratory, skin, urinary and many other bacterial infections; surgical prophylaxis (cefazolin)
How it works	Block bacterial cell-wall synthesis (bactericidal)
Key adverse effects	Allergy up to anaphylaxis, rash, diarrhea and C. difficile (up to 2 months later); ceftriaxone: gallbladder sludge, hemolytic anemia
Assess before giving	Allergy history to penicillins and cephalosporins before the first dose; cultures first when ordered
Teaching	Finish the full course; take amoxicillin at the start of a meal; report rash, hives, swelling or watery diarrhea
Antidote and interactions	Probenecid raises amoxicillin levels; amoxicillin may weaken combined oral contraceptives; ceftriaxone never with IV calcium at the same time in the same line
NCLEX traps	Amoxicillin causes rash in mononucleosis; ceftriaxone is contraindicated in neonates needing IV calcium and in jaundiced neonates; penicillin allergy raises cephalosporin reaction risk

Vancomycin and aminoglycosides (-mycin, -micin)

MRSA and serious gram-negative infections

Prototypes	Vancomycin; gentamicin, tobramycin, amikacin
Use	Vancomycin IV: MRSA and serious gram-positive infections; oral vancomycin: C. difficile. Aminoglycosides: serious gram-negative infections
How it works	Vancomycin blocks cell-wall synthesis; aminoglycosides block bacterial protein synthesis
Key adverse effects	Both: kidney injury and ototoxicity (tinnitus, vertigo, hearing loss). Vancomycin: upper-body flushing and hypotension with fast infusion, phlebitis. Aminoglycosides: neuromuscular blockade
Assess before giving	Creatinine, BUN, urine output, hearing and balance; drug levels per protocol
Teaching	Report ringing in the ears, dizziness, hearing loss or less urine
Antidote and interactions	Loop diuretics, other aminoglycosides, vancomycin and cisplatin add kidney and ear damage
NCLEX traps	Vancomycin over at least 60 min, no faster than 10 mg/min: flushing usually means it ran too fast. Gentamicin: avoid peaks over 12 and troughs over 2 mcg/mL; ototoxicity is usually permanent

Fluoroquinolones (-floxacin)

Serious urinary, respiratory and GI infections

Prototypes	Ciprofloxacin, levofloxacin, moxifloxacin
Use	Serious urinary, respiratory, GI and bone infections; for simple cystitis, sinusitis or bronchitis only when nothing else will do
How it works	Block bacterial DNA gyrase and topoisomerase
Key adverse effects	Tendinitis and tendon rupture, peripheral neuropathy, CNS effects (boxed); QT prolongation; high or low glucose; photosensitivity; aortic aneurysm; C. difficile
Assess before giving	Age over 60, steroid use, transplant (tendon risk); myasthenia gravis; glucose in diabetes; K⁺ and QT
Teaching	Stop and report tendon pain, tingling or numbness; drink plenty of fluids; limit sun; take 2 h before or 6 h after antacids, iron, calcium or zinc; not with milk or yogurt alone
Antidote and interactions	Raise theophylline (seizures, arrest) and tizanidine (contraindicated); minerals block absorption
NCLEX traps	Worsens myasthenia gravis weakness (avoid); not a first choice in children (joint problems)

Macrolides (-thromycin), tetracyclines (-cycline), metronidazole, SMX-TMP, nitrofurantoin

Other common antibacterials

Prototypes	Azithromycin; doxycycline; metronidazole; sulfamethoxazole-trimethoprim; nitrofurantoin
Use	Respiratory and skin infections; anaerobic and protozoal infections (metronidazole); lower urinary tract infections (nitrofurantoin)
How it works	Macrolides and tetracyclines block bacterial protein synthesis; SMX-TMP blocks folate synthesis
Key adverse effects	Azithromycin: GI upset, QT prolongation, liver injury. Doxycycline: photosensitivity, esophageal ulcers. Metronidazole: metallic taste, neuropathy, seizures. SMX-TMP: SJS/TEN, high K⁺, low glucose, blood dyscrasias. Nitrofurantoin: brown urine, lung reactions, neuropathy, hepatitis
Assess before giving	Sulfa allergy; K⁺ and kidney function on SMX-TMP; CrCl before nitrofurantoin (contraindicated under 60)
Teaching	Doxycycline with plenty of fluid, not right before bed, avoid sun; SMX-TMP with plenty of fluid, stop at the first rash; nitrofurantoin with food; no alcohol during metronidazole and for 3 days after
Antidote and interactions	Antacids, iron and calcium block doxycycline; metronidazole and SMX-TMP raise INR on warfarin; SMX-TMP raises methotrexate and phenytoin; metronidazole raises lithium
NCLEX traps	No tetracyclines in the last half of pregnancy or up to age 8 (permanent tooth staining) except doxycycline for severe illness such as RMSF; no SMX-TMP under 2 months; no nitrofurantoin at term (38–42 weeks) or under 1 month; metronidazole plus alcohol causes a disulfiram-like reaction

Antituberculars (rifampin, isoniazid, pyrazinamide, ethambutol)

Tuberculosis, in combination

Prototypes	Isoniazid, rifampin, pyrazinamide, ethambutol (RIPE)
Use	Tuberculosis; active disease is always treated with a combination
How it works	Each attacks mycobacteria differently; combinations prevent resistance
Key adverse effects	Isoniazid, rifampin and pyrazinamide can injure the liver. Isoniazid: peripheral neuropathy. Rifampin: red-orange body fluids, flu-like syndrome. Pyrazinamide: high uric acid, gout. Ethambutol: optic neuritis, loss of acuity and color vision
Assess before giving	Liver symptoms and tests (isoniazid: seen monthly); uric acid (pyrazinamide); visual acuity before and during ethambutol
Teaching	Isoniazid and rifampin on an empty stomach (rifampin 1 h before or 2 h after a meal with water); avoid daily alcohol; pyridoxine (B₆) prevents isoniazid neuropathy; orange urine and tears are expected and stain soft contacts
Antidote and interactions	Rifampin weakens hormonal contraceptives (use another method) and warfarin; isoniazid raises phenytoin; isoniazid with tyramine or histamine foods (aged cheese, tuna) causes flushing, headache, palpitations
NCLEX traps	Ethambutol is contraindicated in patients who cannot report vision changes, such as young children; pyrazinamide is contraindicated in acute gout and severe liver damage

Antivirals (-vir) and antifungals (-azole, nystatin, amphotericin B)

Herpes, influenza, candida and serious fungal infections

Prototypes	Acyclovir, valacyclovir; oseltamivir; fluconazole; nystatin; amphotericin B
Use	Herpes simplex and zoster; influenza treatment and prophylaxis; candida (thrush, vaginal, systemic); serious fungal infections (amphotericin)
How it works	Acyclovir blocks viral DNA polymerase; oseltamivir blocks influenza neuraminidase; azoles block fungal cell-membrane synthesis
Key adverse effects	IV acyclovir: crystal kidney injury, phlebitis, confusion. Oseltamivir: nausea, vomiting, abnormal behavior (children). Fluconazole: liver injury, QT prolongation. Amphotericin B: fever, chills, kidney injury, low K⁺ and Mg²⁺
Assess before giving	Creatinine and hydration (acyclovir, amphotericin); K⁺ and Mg²⁺ (amphotericin); liver tests (fluconazole)
Teaching	Oseltamivir within 48 h of symptoms, 75 mg twice daily for 5 days, with food if nauseated; it does not replace the flu vaccine; continue nystatin 48 h after cure
Antidote and interactions	Fluconazole raises warfarin, phenytoin and sulfonylureas (hypoglycemia); the live nasal flu vaccine and oseltamivir interfere (2 weeks before, 48 h after)
NCLEX traps	IV acyclovir over at least 1 h with good hydration, never a bolus; nystatin is barely absorbed and works locally

SSRIs (-oxetine, -pram, sertraline)

Depression and anxiety disorders

Prototypes	Sertraline, fluoxetine, escitalopram, citalopram, paroxetine
Use	Depression, anxiety disorders, OCD, PTSD
How it works	Block serotonin reuptake
Key adverse effects	Nausea, sexual dysfunction, sleep changes, hyponatremia (older adults, diuretics), bleeding, mania in bipolar disorder, discontinuation symptoms
Assess before giving	Suicide risk, especially in children, teens and young adults and after dose changes (boxed); bipolar screening; Na⁺ in older adults
Teaching	The effect builds over weeks; do not stop abruptly (taper); report agitation, worsening mood or suicidal thoughts
Antidote and interactions	MAOIs (including linezolid and IV methylene blue) contraindicated: 14 days apart (5 weeks after fluoxetine before an MAOI); NSAIDs, aspirin, warfarin add bleeding; triptans, tramadol, lithium add serotonin syndrome
NCLEX traps	Serotonin syndrome: mental status changes, autonomic instability, neuromuscular signs (tremor, rigidity), GI upset: stop the drugs. Pimozide is contraindicated with sertraline

SNRIs (-faxine, duloxetine)

Depression and generalized anxiety

Prototypes	Venlafaxine, duloxetine
Use	Depression, generalized anxiety disorder
How it works	Block serotonin and norepinephrine reuptake
Key adverse effects	Sustained BP rise, nausea, discontinuation syndrome, serotonin syndrome, bleeding; duloxetine: liver injury, orthostatic hypotension, falls
Assess before giving	BP before starting and regularly; suicide risk (boxed); alcohol use and liver disease (duloxetine)
Teaching	Venlafaxine XR once daily with food; swallow capsules whole; taper, never stop abruptly; avoid heavy alcohol on duloxetine
Antidote and interactions	Same MAOI and serotonergic rules as SSRIs; aspirin, NSAIDs and warfarin add bleeding
NCLEX traps	Avoid in untreated narrow-angle glaucoma; venlafaxine is not approved in children

Tricyclic antidepressants (-triptyline, -ipramine)

Depression; lethal in overdose

Prototypes	Amitriptyline, nortriptyline, imipramine
Use	Depression
How it works	Block norepinephrine and serotonin reuptake, with strong anticholinergic effects
Key adverse effects	Dry mouth, constipation, urinary retention, blurred vision; sedation; orthostatic hypotension and falls; arrhythmias and conduction delay
Assess before giving	Suicide risk and how many pills are at home (overdose is lethal); orthostatic BP; bowel and bladder function; ECG in heart disease
Teaching	Take at bedtime (sedation); full effect can take up to 30 days; rise slowly
Antidote and interactions	MAOIs: at least 14 days apart; other anticholinergics and sedatives add effects
NCLEX traps	Overdose: a limb-lead QRS of 0.10 s or more signals severity. Avoid in recovery after MI, angle-closure glaucoma and urinary retention; older adults are especially sensitive

MAO inhibitors (phenelzine, tranylcypromine, selegiline)

Depression; tyramine and drug interactions

Prototypes	Phenelzine, tranylcypromine; selegiline patch
Use	Depression
How it works	Block monoamine oxidase: more norepinephrine, serotonin and dopamine
Key adverse effects	Hypertensive crisis with tyramine foods or interacting drugs; postural hypotension; serotonin syndrome
Assess before giving	BP lying and standing; full list of medicines, including OTC and herbal
Teaching	Avoid aged cheese, pickled herring, liver, dry or fermented sausage, fava bean pods, yogurt, beer and wine (including alcohol-free) during treatment and 2 weeks after; no OTC decongestants or cough medicine with dextromethorphan
Antidote and interactions	Contraindicated with SSRIs, SNRIs, TCAs, meperidine, dextromethorphan and sympathomimetics (amphetamines, methylphenidate, cocaine); 14 days between an MAOI and other antidepressants, 5 weeks after fluoxetine
NCLEX traps	Hypertensive crisis: occipital headache, stiff or sore neck, palpitations: hold the drug and check BP

Lithium (mood stabilizer)

Bipolar disorder; narrow therapeutic range

Prototypes	Lithium carbonate
Use	Bipolar disorder: acute mania and maintenance
How it works	Stabilizes mood; exact mechanism unknown
Key adverse effects	Polyuria and thirst (nephrogenic DI), hypothyroidism, kidney damage with long use. Toxicity: vomiting, diarrhea, drowsiness, weakness, blurred vision, clumsiness, twitching, then seizures and coma
Assess before giving	Level 12 h after the last dose: 0.8–1.2 mEq/L for acute mania, 0.8–1.0 maintenance; Na⁺, creatinine; thyroid tests at baseline, 3 months, then every 6–12 months
Teaching	Normal salt intake and 2,500–3,000 mL of fluid a day, at least early on; sweating, vomiting, diarrhea or fever raise levels; stop and call for vomiting, diarrhea, drowsiness, weakness or clumsiness
Antidote and interactions	Diuretics, ACE inhibitors, ARBs, NSAIDs and metronidazole raise levels; SSRIs, SNRIs, triptans and other serotonergic drugs add serotonin syndrome
NCLEX traps	Toxicity can occur near therapeutic levels (boxed); low sodium raises lithium; possible Ebstein anomaly (risk likely small); not recommended at CrCl under 30

Antipsychotics: first generation (haloperidol) and second generation (-apine, -idone)

Psychosis, schizophrenia, bipolar mania

Prototypes	Haloperidol (first generation); risperidone, olanzapine, quetiapine, clozapine (second generation)
Use	Schizophrenia and other psychoses; bipolar mania (several second-generation drugs)
How it works	Block dopamine D₂ receptors; second-generation drugs also block serotonin 5-HT₂A
Key adverse effects	First generation: EPS (dystonia, akathisia, parkinsonism), tardive dyskinesia, QT prolongation (IV haloperidol, an unapproved route). Second generation: weight gain, high glucose and lipids, orthostasis, prolactin rise (risperidone). All: NMS
Assess before giving	Abnormal movements; temperature, rigidity and mental status (NMS); weight, fasting glucose and lipids at baseline and during second-generation drugs; orthostatic BP
Teaching	Report fever with stiff muscles at once; rise slowly; keep weight and glucose checks; report restlessness or muscle spasms
Antidote and interactions	Antiparkinson drugs such as benztropine treat EPS but not tardive dyskinesia; do not use epinephrine for haloperidol-related hypotension
NCLEX traps	NMS: high fever, rigidity, altered mental status, unstable vitals: stop the drug. Clozapine: severe neutropenia (ANC weekly for 6 months, every 2 weeks to month 12, then monthly; hold for fever 38.5 °C or more and check ANC), seizures, myocarditis, constipation to ileus. Boxed: more deaths in older adults with dementia-related psychosis

Benzodiazepines (-azepam, -azolam)

Anxiety, seizures, alcohol withdrawal, sedation

Prototypes	Lorazepam, alprazolam, diazepam, midazolam; reversal: flumazenil
Use	Short-term relief of anxiety; status epilepticus; alcohol withdrawal; procedural sedation
How it works	Enhance GABA-A inhibition in the brain
Key adverse effects	Sedation, unsteadiness, confusion in older adults, respiratory depression (with opioids or alcohol), dependence and withdrawal, paradoxical agitation
Assess before giving	Respirations and sedation level; fall risk; other CNS depressants on the list
Teaching	No alcohol; no driving until the effect is known; taper, never stop suddenly after regular use (withdrawal seizures)
Antidote and interactions	Flumazenil 0.2 mg IV over 15 s, repeated each minute to 1 mg total; resedation is common; can trigger seizures in long-term users. Opioids plus benzodiazepines: profound sedation, respiratory depression, death (boxed)
NCLEX traps	Older adults: start low (oral lorazepam 1–2 mg a day in divided doses) and use fall precautions; flumazenil does not reverse opioids

ADHD drugs: stimulants and atomoxetine

Methylphenidate, amphetamines, nonstimulant atomoxetine

Prototypes	Methylphenidate, amphetamine salts (Schedule II stimulants); atomoxetine (nonstimulant)
Use	Attention-deficit/hyperactivity disorder
How it works	Stimulants raise dopamine and norepinephrine; atomoxetine selectively blocks norepinephrine reuptake
Key adverse effects	Appetite loss, slower weight gain and growth, insomnia, raised BP and heart rate, anxiety, headache, new psychosis or mania, finger color changes (Raynaud), priapism. Atomoxetine: suicidal thinking in children (boxed), liver injury
Assess before giving	Height, weight, BP and heart rate; mania risk; abuse risk
Teaching	Methylphenidate 30–45 min before meals; last dose before 6 p.m. if it disturbs sleep; high abuse potential, never share; report painful or lasting erections
Antidote and interactions	MAOIs now or within 14 days: contraindicated
NCLEX traps	Growth checks are routine and treatment may pause if a child is not growing as expected; atomoxetine is stopped for jaundice or liver injury

Antiepileptics (phenytoin, levetiracetam, carbamazepine, valproate)

Seizures; valproate also mania

Prototypes	Phenytoin, levetiracetam, carbamazepine, valproate
Use	Seizure disorders; valproate also bipolar mania
How it works	Reduce abnormal neuronal firing by several mechanisms
Key adverse effects	Phenytoin: gum overgrowth, nystagmus and ataxia (toxicity), SJS/TEN, high glucose, bone loss. Levetiracetam: drowsiness, irritability, aggression, psychosis. Carbamazepine: SJS/TEN, aplastic anemia, agranulocytosis, low Na⁺. Valproate: liver failure, pancreatitis, low platelets, high ammonia, birth defects
Assess before giving	Levels: phenytoin 10–20 mcg/mL, carbamazepine 4–12, valproate 50–100 (epilepsy); CBC (carbamazepine, valproate), liver tests (valproate), Na⁺ (carbamazepine)
Teaching	Never stop suddenly (status epilepticus); good dental care on phenytoin; no driving until the effect is known; carbamazepine with meals, no grapefruit; swallow Depakote whole
Antidote and interactions	Phenytoin and carbamazepine weaken hormonal contraceptives; tube feedings lower phenytoin absorption; all antiepileptics carry a suicidal-thinking warning
NCLEX traps	IV phenytoin no faster than 50 mg/min in adults, with cardiac monitoring, in saline only (precipitates in dextrose), flushed with saline; screen HLA-B*1502 before carbamazepine in at-risk ancestry; valproate liver risk is highest under age 2

Parkinson drugs: carbidopa-levodopa and anticholinergics

Parkinson disease and drug-induced EPS

Prototypes	Carbidopa-levodopa; benztropine; pramipexole, ropinirole (dopamine agonists)
Use	Parkinson disease; benztropine also drug-induced EPS (not tardive dyskinesia)
How it works	Levodopa becomes dopamine in the brain; carbidopa stops it breaking down outside the brain (less nausea)
Key adverse effects	Dyskinesias, orthostatic hypotension, hallucinations, falling asleep without warning, impulse-control problems (gambling, spending, binge eating), dark saliva, urine or sweat. Benztropine: dry mouth, urinary retention, reduced sweating
Assess before giving	Movement symptoms and dyskinesias; orthostatic BP; mental status
Teaching	High-protein meals can delay levodopa absorption; dark urine or sweat can occur; no driving with sudden sleep episodes; benztropine: caution in hot weather (no sweating)
Antidote and interactions	Nonselective MAOIs must stop at least 2 weeks before levodopa
NCLEX traps	Do not stop levodopa abruptly (NMS-like reaction); levodopa is contraindicated in narrow-angle glaucoma; benztropine is contraindicated under age 3

Cholinesterase inhibitors (-stigmine, donepezil) and memantine

Alzheimer dementia and myasthenia gravis

Prototypes	Donepezil, rivastigmine; memantine (NMDA blocker); pyridostigmine (myasthenia gravis)
Use	Alzheimer dementia (memantine for moderate to severe); myasthenia gravis (pyridostigmine)
How it works	Block acetylcholinesterase so more acetylcholine reaches receptors; memantine blocks NMDA receptors
Key adverse effects	Nausea, vomiting, diarrhea, weight loss, bradycardia and syncope, GI bleeding risk; pyridostigmine overdose: cholinergic crisis (salivation, cramps, diarrhea, sweating, more weakness). Memantine: headache, diarrhea, dizziness
Assess before giving	Heart rate (vagal slowing), weight, GI bleeding; in myasthenia: strength, swallowing and breathing
Teaching	Donepezil in the evening before bed; it eases symptoms but does not change the disease course; pyridostigmine doses are timed for when strength is needed most
Antidote and interactions	Atropine for cholinergic crisis; donepezil exaggerates succinylcholine; NSAIDs add GI bleeding; alkaline urine raises memantine
NCLEX traps	More weakness on pyridostigmine may be cholinergic crisis (too much) or myasthenic crisis (too little) and is hard to tell apart at the bedside; caution in asthma

Multiple sclerosis disease-modifying drugs

Interferon beta and glatiramer

Prototypes	Interferon beta-1a (Avonex); glatiramer acetate (Copaxone)
Use	Relapsing forms of multiple sclerosis
How it works	Modify the immune attack on myelin
Key adverse effects	Interferon: flu-like symptoms, depression and suicidal thoughts, liver injury, injection-site necrosis, seizures, worse heart failure. Glatiramer: post-injection reaction (flushing, chest pain, palpitations, dyspnea within minutes), anaphylaxis (boxed), lipoatrophy
Assess before giving	Mood and suicidal thoughts (interferon); CBC, liver tests and thyroid tests on interferon; injection sites
Teaching	Avonex 30 mcg IM once weekly, with an analgesic or antipyretic for flu-like symptoms; rotate sites; glatiramer 20 mg SC daily or 40 mg three times weekly (not interchangeable)
Antidote and interactions	No key bedside interactions; follow the specialty monitoring plan
NCLEX traps	Glatiramer post-injection reactions are brief, but anaphylaxis can start any time, even years in, and can look the same; skip a site until it heals

Immunosuppressants (tacrolimus, cyclosporine) and biologics (-mab)

Transplant and autoimmune disease

Prototypes	Tacrolimus, cyclosporine (calcineurin inhibitors); adalimumab, infliximab (TNF blockers)
Use	Prevent transplant rejection; rheumatoid arthritis, Crohn disease, psoriasis and other autoimmune diseases (TNF blockers)
How it works	Calcineurin inhibitors block T-cell activation; TNF blockers neutralize tumor necrosis factor α
Key adverse effects	Serious infections and cancers (boxed). Tacrolimus: kidney injury, tremor, PRES, high glucose, high K⁺, hypertension, QT. TNF blockers: TB and hepatitis B reactivation, lymphoma, heart failure, demyelination, injection-site reactions
Assess before giving	Tacrolimus trough level, creatinine, K⁺, glucose; TB test before and during TNF blockers; hepatitis B status
Teaching	Take tacrolimus the same way each day (with or without food); no grapefruit; report fever or infection early; no live vaccines
Antidote and interactions	CYP3A4 inhibitors (ketoconazole, clarithromycin) raise tacrolimus sharply and rifampin lowers it; ACE inhibitors, ARBs and potassium-sparing diuretics add hyperkalemia
NCLEX traps	Treat latent TB before starting a TNF blocker; adult adalimumab is usually 40 mg SC every other week

Chemotherapy basics (methotrexate, cyclophosphamide, vincristine, doxorubicin)

Antineoplastic safety points

Prototypes	Methotrexate; cyclophosphamide; vincristine; doxorubicin
Use	Cancers; methotrexate also rheumatoid arthritis and psoriasis (once weekly)
How it works	Kill dividing cells: methotrexate blocks folate use, cyclophosphamide and doxorubicin damage DNA, vincristine stops mitosis
Key adverse effects	Marrow suppression (infection, bleeding, anemia), mouth sores, nausea, vomiting, hair loss. Methotrexate: liver, lung and kidney toxicity. Cyclophosphamide: hemorrhagic cystitis, infertility. Vincristine: neuropathy, constipation, ileus. Doxorubicin: cardiomyopathy, red urine for 1–2 days
Assess before giving	CBC before each dose; temperature; IV site patency before vesicants; LVEF before and during doxorubicin; kidney function and hydration
Teaching	Report fever or sore throat; drink fluids and void often on cyclophosphamide; bowel regimen with vincristine; contraception during and after treatment
Antidote and interactions	Leucovorin rescue for methotrexate (glucarpidase for toxic levels with slow clearance); mesna protects the bladder from cyclophosphamide; PPIs and NSAIDs can raise methotrexate
NCLEX traps	Vincristine is IV only: intrathecal use is usually fatal. Daily instead of weekly methotrexate has killed patients. Doxorubicin extravasation: stop the infusion and apply ice

Uterotonics: oxytocin, methylergonovine, carboprost

Labor induction and postpartum hemorrhage

Prototypes	Oxytocin; methylergonovine; carboprost
Use	Oxytocin: medically indicated induction or augmentation of labor, postpartum bleeding. Methylergonovine, carboprost: postpartum hemorrhage from atony
How it works	Make the uterus contract; methylergonovine also constricts blood vessels
Key adverse effects	Oxytocin: uterine hyperstimulation, rupture, water intoxication (antidiuretic effect). Methylergonovine: hypertension, coronary or limb vasospasm. Carboprost: vomiting, diarrhea, fever
Assess before giving	Oxytocin: contraction frequency, duration and force, resting tone, FHR. Methylergonovine: BP before each dose. Carboprost: asthma history
Teaching	Oxytocin by pump, started at 1–2 mU/min or less and raised by no more than 1–2 mU/min; postpartum 10–40 units in 1,000 mL, or 10 units IM after the placenta
Antidote and interactions	Stop oxytocin for hyperstimulation or signs of water intoxication; potent CYP3A4 inhibitors with methylergonovine risk vasospasm
NCLEX traps	Methylergonovine is contraindicated in hypertension, toxemia (preeclampsia) and pregnancy; carboprost: deep IM, caution in asthma, total no more than 2 mg, refrigerated; oxytocin is not for elective induction

Magnesium sulfate (preeclampsia)

Seizure prevention; toxicity checks before every dose

Prototypes	Magnesium sulfate IV (50% diluted to 20% or less)
Use	Prevent and control seizures in preeclampsia and eclampsia; tocolysis is an unapproved use and not beyond 5–7 days (fetal bone loss)
How it works	Depresses the CNS and neuromuscular transmission
Key adverse effects	Flushing, sweating, nausea, weakness, hypotension; toxicity: lost patellar reflex, respiratory depression, cardiac arrest
Assess before giving	Patellar reflexes before each dose (hold if absent), respirations 16 or more, urine output 100 mL or more in the prior 4 h, serum Mg²⁺
Teaching	Loading 4–6 g IV over 15–30 min (premixed label 4–6 g over 15 min; 50% vial label 4–5 g), then 1–2 g/h by pump; no more than 30–40 g in 24 h; explain flushing and warmth
Antidote and interactions	Calcium gluconate at the bedside (label: 10–20 mL of a 5% calcium solution IV); renal impairment lets magnesium build up
NCLEX traps	Seizure control around 2.5–5 mEq/L; reflexes fade above 4 and may vanish at 10, where respiratory paralysis threatens; over 12 can be fatal

Preterm labor: terbutaline (tocolysis) and betamethasone (fetal lungs)

Buy time so steroids can work

Prototypes	Terbutaline (β₂ agonist); betamethasone (antenatal corticosteroid); nifedipine, indomethacin (other tocolytics)
Use	Delay preterm birth briefly so betamethasone can mature fetal lungs; one steroid course when birth is likely within 7 days, generally at 24–33 weeks (ACOG 2017; consider at 34–36 weeks in selected cases)
How it works	Terbutaline relaxes uterine smooth muscle; betamethasone speeds surfactant and lung development
Key adverse effects	Terbutaline: maternal tachycardia, high glucose, low K⁺, pulmonary edema, arrhythmias, myocardial ischemia; newborn hypoglycemia. Betamethasone: maternal hyperglycemia, fluid retention
Assess before giving	Maternal pulse (hold terbutaline over 120), breath sounds, glucose, K⁺; contractions and FHR
Teaching	Betamethasone: 2 doses of 12 mg IM 24 h apart, ideally more than 24 h before birth; it protects the baby’s lungs
Antidote and interactions	Indomethacin: not after 32 weeks (oligohydramnios, ductus problems); nifedipine: hypotension
NCLEX traps	Terbutaline boxed warning: not for prolonged tocolysis beyond 48–72 h (deaths reported); check glucose closely in diabetics after betamethasone

Rh(D) immune globulin (RhoGAM)

Preventing Rh sensitization

Prototypes	Rho(D) immune globulin 300 mcg (RhoGAM)
Use	Rh-negative, unsensitized mother: at 26–28 weeks, within 72 h of delivering an Rh-positive newborn, and after pregnancy loss, ectopic pregnancy, bleeding, trauma or procedures
How it works	Anti-D antibodies clear Rh-positive fetal cells before the mother makes her own antibodies
Key adverse effects	Injection-site discomfort; rare hypersensitivity (IgA-deficient patients at higher risk)
Assess before giving	Mother is Rh-negative and unsensitized; newborn is Rh-positive; test for a large fetomaternal hemorrhage when at risk
Teaching	Watch at least 20 min after the injection; it protects future pregnancies
Antidote and interactions	Live vaccines (MMR, varicella) are generally delayed 3 months after it, but postpartum rubella or MMR vaccine is not delayed
NCLEX traps	IM only for RhoGAM; never given to the newborn or to an Rh-positive mother; one 300 mcg dose covers up to 15 mL of Rh-positive red cells, larger bleeds need more

Childhood vaccines: the basics

Live versus inactivated, contraindications, sites

Prototypes	Live: MMR, varicella, nasal influenza (FluMist). Most others (DTaP, hepatitis B, polio, Hib, pneumococcal, injected influenza) are inactivated
Use	MMR at 12–15 months and 4–6 years (CDC 2026). Hepatitis B: AAP 2026 keeps a dose within 24 h of birth for all newborns; CDC (December 2025) made it an individual decision when the mother is HBsAg-negative; HBsAg-positive mother: vaccine plus HBIG within 12 h
How it works	Train the immune system with weakened live organisms or inactivated parts
Key adverse effects	Soreness, redness, low fever, fussiness; rare anaphylaxis
Assess before giving	Severe allergic reaction to a prior dose or component (contraindication); moderate or severe illness (delay); pregnancy or severe immunosuppression (no live vaccines)
Teaching	Mild illness, low fever or antibiotics are not reasons to delay; avoid pregnancy for 1 month after MMR or varicella
Antidote and interactions	Live vaccines (MMR, varicella) the same day or at least 28 days apart; immune globulin and other antibody products delay MMR and varicella
NCLEX traps	IM site: anterolateral thigh in infants (1-inch needle), deltoid from age 3; no aspiration; separate shots in one limb by 1 inch. Non-severe egg allergy is not a contraindication to injected flu vaccine

Potassium chloride (KCl)

Hypokalemia replacement

Prototypes	Oral KCl (extended-release); IV KCl (premixed, or concentrate diluted before use)
Use	Treat and prevent hypokalemia (diuretics, digoxin)
How it works	Replaces potassium for nerve, muscle and cardiac conduction
Key adverse effects	Hyperkalemia (paresthesias, weakness, arrhythmias, arrest); oral: GI ulcers and strictures; IV: pain and phlebitis
Assess before giving	Serum K⁺, kidney function and urine output; ECG during IV replacement
Teaching	Oral: with meals and a full glass of water; do not chew; report black stools, vomiting or abdominal pain
Antidote and interactions	Potassium-sparing diuretics (oral KCl with triamterene or amiloride is contraindicated), ACE inhibitors and ARBs raise K⁺
NCLEX traps	Never IV push: undiluted concentrate can be instantly fatal. Usual IV rate no more than 10 mEq/h (up to 40 mEq/h only for severe deficits with continuous cardiac monitoring); usually no more than 200 mEq in 24 h

Iron, vitamin B₁₂, folic acid and vitamin K

Anemia, neural tube defects, newborn bleeding

Prototypes	Ferrous sulfate; iron dextran (IV or IM); cyanocobalamin injection; folic acid; phytonadione
Use	Iron deficiency anemia; pernicious anemia (B₁₂); preventing neural tube defects (folic acid); newborn bleeding prevention and warfarin reversal (vitamin K)
How it works	Replace what the body lacks for red cell production or clotting-factor synthesis
Key adverse effects	Oral iron: constipation, nausea, black stools. Iron dextran: anaphylaxis (boxed). Early B₁₂ treatment: low K⁺. IV or IM vitamin K: severe, sometimes fatal reactions (boxed)
Assess before giving	Hemoglobin and hematocrit to track the response to iron; K⁺ in the first 48 h of B₁₂ therapy; INR with vitamin K
Teaching	Iron 1 h before or 2 h after meals (with food if it upsets the stomach), with vitamin C (orange juice), more fiber for constipation. Folic acid 0.4–0.8 mg daily from at least 1 month before conception. Pernicious anemia: B₁₂ injections monthly for life
Antidote and interactions	Antacids and PPIs reduce iron absorption, and iron blocks doxycycline; folic acid can hide B₁₂ deficiency while nerve damage progresses; vitamin K does not reverse heparin
NCLEX traps	Iron dextran: test dose first; IM injections only by Z-track into the upper outer buttock. Oral B₁₂ is unreliable in pernicious anemia. Newborn vitamin K: 0.5–1 mg IM within 1 h of birth

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For education and exam preparation only. Follow your institution’s protocols. Typical adult values for study. Follow the order, the label and your institution's protocols.