Losartan × Tadalafil

Tadalafil is a phosphodiesterase type 5 (PDE5) inhibitor with vasodilator properties: on its own it causes a slight and transient fall in blood pressure (tadalafil SmPC, EMA). Losartan lowers blood pressure by blocking angiotensin II receptors, and other substances with a hypotensive effect add to its action (losartan SmPC). In studies with angiotensin II receptor blockers tadalafil 20 mg produced a small additional fall in blood pressure without a clinically significant interaction; in people with uncontrolled hypertension the fall was larger, but in most of them without symptoms of hypotension (tadalafil SmPC, EMA). The interaction is pharmacodynamic: two blood-pressure-lowering effects add up (Cialis label, FDA).

Usually none: the fall in blood pressure is small and not clinically relevant (tadalafil SmPC, EMA). Dizziness, weakness or light-headedness on standing can signal a drop in blood pressure; the risk is higher with uncontrolled hypertension and with volume or sodium depletion from diuretics, diarrhoea, vomiting or a salt-restricted diet, when losartan itself can cause symptomatic hypotension (tadalafil and losartan SmPCs).

By the SmPCs the combination is acceptable and no dose change of losartan or tadalafil is needed: no clinically significant interaction with angiotensin II receptor blockers was found (tadalafil SmPC, EMA). The patient is told that blood pressure may fall slightly in addition to antihypertensive treatment (tadalafil SmPC, EMA). Before tadalafil is prescribed, cardiovascular status is assessed, because sexual activity itself carries some cardiac risk (tadalafil SmPC, EMA); with uncontrolled hypertension or blood pressure below 90/50 mm Hg tadalafil is not recommended, and in people with uncontrolled hypertension the fall in pressure was larger (Cialis label, FDA; tadalafil SmPC, EMA). Volume or sodium depletion after diuretics, diarrhoea or vomiting is corrected before losartan starts, or losartan is started at a lower dose (losartan SmPC).