Reference — Pharmacology
Drug Classes Reference
A concise overview of major drug classes tested on NCLEX and encountered in clinical practice — mechanism of action, representative drugs, indications, and the nursing considerations that matter most.
Educational use only. This reference supports learning and clinical practice. Always verify medication information against current drug references (e.g., Davis's Drug Guide, clinical pharmacist) and institutional protocols before administration. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.
ACE Inhibitors
Mechanism of Action
Block angiotensin-converting enzyme → prevent angiotensin II formation → vasodilation + decreased aldosterone
Common Drugs
Lisinopril, Enalapril, Captopril, Ramipril
Indications
Hypertension, heart failure, post-MI, diabetic nephropathy
Nursing Considerations
- Monitor BP — first-dose hypotension risk
- Watch for dry cough (class effect) — if intolerable, switch to ARB
- Monitor K⁺ and renal function — can cause hyperkalemia
- Contraindicated in pregnancy (teratogenic)
- Hold before IV contrast if CKD present
Beta-Blockers
Mechanism of Action
Block β-adrenergic receptors → decrease heart rate, contractility, and blood pressure
Common Drugs
Metoprolol, Atenolol, Carvedilol, Propranolol, Labetalol
Indications
Hypertension, heart failure, post-MI, angina, arrhythmias
Nursing Considerations
- Check apical pulse before administration — hold if < 60 bpm (per order)
- Do not abruptly discontinue — rebound tachycardia / angina risk
- Cardioselective (metoprolol, atenolol) preferred in asthma/COPD
- Monitor for bradycardia, hypotension, fatigue
- Masks signs of hypoglycemia (tachycardia) in diabetic patients
Calcium Channel Blockers
Mechanism of Action
Block L-type calcium channels → vasodilation (dihydropyridines) or decreased heart rate/conduction (non-DHP)
Common Drugs
Amlodipine, Nifedipine (DHP); Diltiazem, Verapamil (non-DHP)
Indications
Hypertension, angina, atrial fibrillation (non-DHP), Raynaud's
Nursing Considerations
- Non-DHP (diltiazem, verapamil) — hold if HR < 60 or BP low
- Monitor for peripheral edema (common with DHP class)
- Do not crush or split extended-release formulations
- Grapefruit juice increases drug levels — instruct patient to avoid
- Constipation is common with verapamil
Diuretics — Loop
Mechanism of Action
Inhibit Na⁺-K⁺-2Cl⁻ cotransporter in thick ascending loop of Henle → significant sodium and water excretion
Common Drugs
Furosemide (Lasix), Bumetanide, Torsemide
Indications
Heart failure, pulmonary edema, hypertension, hyperkalemia
Nursing Considerations
- Monitor I&O, daily weight — watch for excessive fluid loss
- Monitor K⁺, Na⁺, Mg²⁺ — electrolyte wasting (especially hypokalemia)
- Administer in the morning to avoid nocturnal diuresis
- Assess for ototoxicity with high doses or rapid IV infusion
- Sulfonamide allergy: cross-reactivity possible (verify with provider)
Diuretics — Thiazide
Mechanism of Action
Inhibit Na⁺-Cl⁻ cotransporter in distal convoluted tubule → moderate sodium/water excretion
Common Drugs
Hydrochlorothiazide (HCTZ), Chlorthalidone, Metolazone
Indications
Hypertension (first-line), mild heart failure, nephrolithiasis (calcium stones)
Nursing Considerations
- Monitor K⁺ — causes hypokalemia (less than loop diuretics)
- Monitor uric acid — can precipitate gout
- Monitor glucose — can cause hyperglycemia
- Monitor Ca²⁺ — thiazides retain calcium (unlike loop diuretics)
- Advise sun protection — photosensitivity risk
Statins (HMG-CoA Reductase Inhibitors)
Mechanism of Action
Inhibit HMG-CoA reductase → reduced cholesterol synthesis → increased LDL receptor expression
Common Drugs
Atorvastatin, Rosuvastatin, Simvastatin, Pravastatin, Lovastatin
Indications
Hyperlipidemia, primary/secondary prevention of ASCVD
Nursing Considerations
- Administer in the evening (cholesterol synthesized mostly at night) — unless 24h drug
- Monitor LFTs at baseline and periodically
- Assess for myopathy: muscle pain, weakness — check CK if symptomatic
- Rare but serious: rhabdomyolysis (especially with drug interactions)
- Grapefruit increases levels of simvastatin/lovastatin — advise avoidance
Opioid Analgesics
Mechanism of Action
Bind μ-opioid receptors in CNS and PNS → inhibit pain transmission, alter pain perception
Common Drugs
Morphine, Hydromorphone, Oxycodone, Fentanyl, Codeine, Tramadol
Indications
Moderate-severe acute/chronic pain, post-op pain, palliative care
Nursing Considerations
- Monitor respiratory rate and SpO₂ — hold and notify provider if RR < 12
- Have naloxone (Narcan) readily available
- Assess sedation level before each dose
- Monitor bowel function — constipation is universal; prophylactic stool softeners
- Assess pain before and ~30–60 min after administration to evaluate effect
- Risk of dependence and diversion — document carefully
Antibiotics — Penicillins
Mechanism of Action
Inhibit cell wall synthesis by binding penicillin-binding proteins (PBPs) → bactericidal
Common Drugs
Amoxicillin, Ampicillin, Penicillin G/V, Piperacillin-Tazobactam (Zosyn)
Indications
Strep pharyngitis, skin/soft tissue, pneumonia, UTI, gram-negative infections (pip-tazo)
Nursing Considerations
- Allergy history essential — cross-reactivity with cephalosporins (~1–2%)
- Take with or without food (amoxicillin); food may decrease absorption of some forms
- Monitor for hypersensitivity reactions — anaphylaxis risk (have epinephrine available)
- Collect cultures before first dose when possible
- Remind patients to complete full course even if feeling better
Corticosteroids
Mechanism of Action
Bind glucocorticoid receptors → suppress inflammation and immune response; mineralocorticoid effects vary
Common Drugs
Prednisone, Methylprednisolone (Solu-Medrol), Dexamethasone, Hydrocortisone
Indications
Asthma exacerbation, allergic reactions, autoimmune disorders, adrenal insufficiency, anti-emetic (dexamethasone)
Nursing Considerations
- Monitor blood glucose — can cause hyperglycemia (even in non-diabetics)
- Monitor BP, weight, and sodium — sodium/water retention
- Do not abruptly discontinue long-term therapy — adrenal suppression risk
- Administer with food to reduce GI irritation
- Monitor for signs of infection — steroids mask fever and immune response
- Long-term: osteoporosis, Cushing features, skin fragility
Anticoagulants
Mechanism of Action
Heparin: activates antithrombin III → inhibits thrombin/Xa. Warfarin: inhibits vitamin K–dependent factors (II, VII, IX, X). DOACs: direct factor Xa or thrombin inhibition
Common Drugs
Heparin, Warfarin (Coumadin), Enoxaparin (Lovenox); DOACs: Rivaroxaban, Apixaban, Dabigatran
Indications
DVT/PE treatment and prevention, atrial fibrillation, mechanical valves, ACS
Nursing Considerations
- Monitor aPTT (heparin), INR (warfarin), or anti-Xa levels per protocol
- Assess for bleeding: gums, urine, stool, bruising, neurological changes
- Antidotes: Protamine sulfate (heparin), Vitamin K / FFP (warfarin), Andexanet alfa (Xa inhibitors), Idarucizumab (dabigatran)
- Warfarin: dietary consistency for vitamin K important; multiple drug interactions
- Fall precautions; instruct patient on signs of bleeding to report
Standards & sources
Fact-checked Jun 20, 2026This page is written to align with Institute for Safe Medication Practices (ISMP) · FDA prescribing information · The Joint Commission — National Patient Safety Goals. It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →