PH4.7 | PH4.7 | Hypertension Pharmacotherapy — Summary & Reflection

KEY TAKEAWAYS

Antihypertensive pharmacotherapy spans eight drug classes, each targeting a different determinant of blood pressure — cardiac output, peripheral vascular resistance, or both. First-line agents for uncomplicated hypertension are thiazide-like diuretics (chlorthalidone preferred), ACEi/ARBs, and dihydropyridine CCBs (amlodipine); beta-blockers are reserved for hypertension with comorbid angina, HFrEF, or post-MI. The critical comorbidity-based prescribing rules are: ACEi/ARBs for diabetes + nephropathy; beta-blockers for HFrEF + hypertension (with carvedilol, bisoprolol, or metoprolol succinate); non-DHP CCBs absolutely contraindicated in HFrEF; ACEi/ARBs absolutely contraindicated in pregnancy (methyldopa, labetalol, nifedipine, hydralazine are safe). Hypertensive emergencies require IV agents (labetalol, nicardipine, nitroprusside) with controlled BP reduction (max 20–25% in 1 hour); urgencies use oral agents with gradual reduction over 24–48 hours. Aortic dissection requires esmolol (HR control) plus a vasodilator. Losartan is uniquely preferred in HTN + gout due to its uricosuric effect.

REFLECT

Return to the two women in the opening hook.

Patient 1 (28 weeks pregnant, BP 210/130, papilloedema, encephalopathy): This is a hypertensive emergency in pregnancy (severe eclampsia/hypertensive crisis).
1. Which IV drug do you give first — and what is your BP reduction target in the first hour?
2. What drug is absolutely contraindicated — and why specifically in pregnancy?
3. She also develops seizures. Magnesium sulphate is given — is this an antihypertensive?
4. After stabilisation, what oral agent will you continue for the rest of the pregnancy?

Patient 2 (BP 185/115, asymptomatic, no TOD): Hypertensive urgency.
5. Which oral drug is appropriate for acute control?
6. What investigations would you order to rule out secondary hypertension before starting chronic therapy?

Reflect on how your pharmacological framework — mechanism, indication, contraindication — translates into a management plan for the most acute presentations you will ever face.