Antihypertensive Drug Selection
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Direct answer
Antihypertensive selection is not one decision but a match between patient and compelling indication: thiazides, calcium channel blockers, ACE inhibitors and ARBs are the first-line four for uncomplicated hypertension, while comorbidity redirects the choice — ACE inhibitor or ARB for proteinuric diabetes, beta-blocker plus ACE inhibitor after infarction, spironolactone add-on for resistant hypertension, and labetalol, methyldopa or nifedipine in pregnancy. Hypertensive emergencies demand intravenous therapy (labetalol, nitroprusside, nicardipine) with controlled reduction over 24–48 hours, whereas urgency is managed orally.
What you must remember
- First-line classes for most patients: thiazide-type diuretic, calcium channel blocker, ACE inhibitor, ARB — start one, titrate to target (below 140/90 generally, below 130/80 in many high-risk groups per current guidance).
- Compelling indications framework: diabetes with proteinuria — ACE inhibitor/ARB; post-myocardial infarction — beta-blocker plus ACE inhibitor; heart failure — ACE inhibitor/ARB, beta-blocker, mineralocorticoid antagonist, diuretic; chronic kidney disease with proteinuria — ACE inhibitor/ARB.
- Pregnancy: labetalol, methyldopa, nifedipine, hydralazine; ACE inhibitors and ARBs are contraindicated throughout.
- Beta-blockers are no longer first-line for uncomplicated hypertension but remain mandatory with angina, heart failure, post-infarction and rate control.
- Avoid: thiazides in gout; beta-blockers in asthma and peripheral vascular disease with rest pain; non-dihydropyridines in systolic heart failure; ACE inhibitors in bilateral renal artery stenosis and pregnancy.
- Resistant hypertension (uncontrolled on three drugs including a diuretic at optimal dose): add spironolactone 25 mg — the proven fourth drug.
- Hypertensive emergency (pressure above 180/120 with acute target-organ damage): labetalol, nicardipine, nitroprusside, or enalaprilat intravenously, lowering mean pressure by no more than 20–25 per cent in the first hours.
- Pheochromocytoma: alpha-blockade before beta; clonidine withdrawal and non-steroidal drugs are classic secondary or resistant causes.
How to work through five different patients
The drug class is chosen by the comorbidity, and five outpatient vignettes cover the map. A 48-year-old diabetic with 2+ proteinuria gets an ACE inhibitor even at modest pressures — renoprotection is the indication, and ARB if he coughs. A 60-year-old two months after an anterior infarction, already on aspirin and statin, gets a beta-blocker plus an ACE inhibitor for prognosis, not merely for pressure. A 70-year-old with isolated systolic hypertension and constipation gets amlodipine or indapamide — a thiazide's stroke data suits the elderly, and indapamide spares his glucose. A 26-year-old woman at 32 weeks of pregnancy at 160/105 gets labetalol orally (or methyldopa), and if she seizes, magnesium sulphate is the anticonvulsant while hydralazine or labetalol intravenously controls pressure. Finally, a 55-year-old on three maximised drugs returns at 150/94 with normal electrolytes: confirm adherence, exclude non-steroidal use and sleep apnoea, screen for secondary causes, then add spironolactone. Each vignette is a row in the compelling-indications table that Indian postgraduate examinations recycle every year.
Where students slip
The penalised answers are predictable. Writing an ACE inhibitor for a pregnant hypertensive is the single most punished error in the chapter. Second, reaching for sublingual nifedipine in hypertensive emergency — an uncontrolled precipitous fall in pressure can cause stroke or infarction; the exam wants controlled intravenous reduction or oral therapy over 24–48 hours. Third, forgetting that in a patient of African ancestry or the elderly with low-renin hypertension, calcium channel blockers and thiazides outperform renin-angiotensin monotherapy — a pharmacodynamic point about renin status rather than an epidemiological one. Fourth, missing secondary-cause clues: young age, sudden onset, abdominal bruit, hypokalaemia without diuretics (Conn syndrome), and paroxysmal sweating-palpitation-headache triads (phaechromocytoma) each redirect the work-up before any drug is chosen.
Frequently asked questions
Which four classes are first-line for uncomplicated hypertension?
Thiazide-type diuretics, calcium channel blockers, ACE inhibitors and ARBs, chosen by comorbidity, cost and tolerability, titrated to target and combined rationally rather than maximised sequentially.
How is hypertension managed in pregnancy?
Labetalol, methyldopa, extended-release nifedipine or hydralazine, with magnesium sulphate for eclamptic seizures; ACE inhibitors and ARBs are absolutely contraindicated at every stage.
What defines resistant hypertension and its next step?
Blood pressure above goal on three drugs including a diuretic at optimal doses; after excluding non-adherence, NSAIDs and secondary causes, add spironolactone 25 mg — the best-evidenced fourth drug.
Why is sublingual nifedipine condemned in hypertensive emergencies?
It produces abrupt unpredictable falls in pressure, risking cerebral and myocardial ischaemia; controlled intravenous reduction of mean arterial pressure by 20–25 per cent in the first hours is the standard.
Which antihypertensive suits a patient with coexisting benign prostatic hyperplasia?
An alpha-1 blocker such as doxazosin can be added for both indications, though it is add-on therapy rather than first-line for pressure alone.