Beta blockers Alfuzosin

ALPHA-BLOCKERS BETA-BLOCKERS t efficacy of alpha-blockers t risk of first-dose 1 BP when alfuzosin, prazosin or terazosin is started in patients already taking beta-blockers Additive hypotensive effect may be used therapeutically Monitor BP at least weekly until stable. Warn patients to report symptoms of hypotension (lightheadedness, dizziness on standing, etc.). Watch for first-dose 1 BP... 

Direct information is limited. Acute hypotension (dizziness, fainting) sometimes occurs unpredictably with the first dose of some alpha blockers (particularly, alfuzosin, prazosin and terazosin but see Alpha blockers , (p.83)), and this can be exaggerated if the patient takes or is already taking a beta blocker or a calcium-channel blocker (see Alpha blockers + Beta blockers , below, and Alpha blockers + Calcium-channel blockers , p.85). It would therefore seem prudent to apply the same precautions to ACE inhibitors, namely reducing the dose of the ACE inhibitor to a maintenance level if possible, then starting the alpha blocker at the lowest dose, with the first dose given at bedtime. Note that the acute hypotensive reaction appears to be short-lived. There is limited evidence that terazosin and tamsulosin may not cause an additional hypotensive effect in the longer term in patients with BPH who have hypertension already well-controlled with ACE inhibitors. Nevertheless, caution should be exercised in this situation, and a dose reduction of the ACE inhibitor may be required. 

The risk of first-dose hypotension with prazosin is higher if the patient is already taking a beta blocker. This is also likely to be true of other alpha blockers, particularly alfuzosin, bunazosin and terazosin. In a small study tamsulosin did not have any clinically relevant effects on blood pressure that was already well controlled by atenolol. Alpha blockers and beta blockers may be combined for additional lowering of blood pressure in patients with hypertension. 

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