Enalapril × Hydrochlorothiazide

Additive antihypertensive effect. In the first weeks hydrochlorothiazide increases renin-angiotensin system activity, raising sensitivity to the ACE inhibitor. A standard fixed combination for arterial hypertension.

Symptomatic hypotension on starting: dizziness, weakness, especially on standing. In older patients: fall risk. Potassium monitoring matters — thiazide depletes, ACE inhibitor retains.

On starting the combination, begin enalapril at the lowest dose (2.5 mg) at bedtime. Check creatinine and potassium at 1–2 weeks, then every 6 months. In older patients, take the first dose seated.