Severe first-dose hypotension, and synergistic hypotensive effects have occurred in patients given
alpha blockers with
ACE inhibitors.
Angiotensin II receptor antagonists are predicted to interact similarly.
Acute hypotension (dizziness, fainting) sometimes occurs unpredictably with the first dose of some
alpha blockers (particularly
alfuzosin, prazosin and terazosin), and this can be exaggerated by other
antihypertensives.
Angiotensin II receptor antagonists would be expected to have a similar effect. Minimise the risk by starting with a low dose of alpha blocker, preferably given at bedtime, and escalate the dose slowly over a couple of weeks. Patients should be warned to lie down if
symptoms such as dizziness,
fatigue or sweating develop, and to remain lying down until
symptoms abate.