Three retrospective studies have recently reported an association between beta-blocker use and a reduction in breast cancer metastasis and recurrence. No prospective, randomized trials have been published.

Betaxolol (Kerlone - Searle), an oral beta-adrenergic blocker, was recently approved by the US Food and Drug Administration for once-daily treatment of hypertension. The new drug is beta 1 (cardio)-selective with no intrinsic sympathomimetic (partial agonist) activity. It is also available in a topical formulation for treatment of glaucoma (Betoptic - Medical Letter, 28:45, 1986). Beta-blockers currently available in the USA for treatment of hypertension are listed in the table below.

Doxazosin (mesylate - Roerig), an alpha1-adrenergic receptor blocker similar to prazosin (Minipress, and others) and terazosin (Hytrin), was recently approved by the US Food and Drug Administration for treatment of hypertension.

Carteolol (Cartrol - Abbott) and penbutolol (Levatol - Reed & Carnrick), two oral beta-adrenergic blocking drugs, were recently approved by the US Food and Drug Administration for once-daily treatment of systemic hypertension. Both drugs are non-selective beta-blockers with mild partial agonist activity. Beta-blockers currently available in the USA for treatment of hypertension are listed in the table on the next page.

Angiotensin receptor blockers (ARBs) are widely used as an alternative to angiotensin converting enzyme (ACE) inhibitors for treatment of hypertension because they lower blood pressure without inducing a cough. It has not been established that they provide the same cardiac benefits as ACE inhibitors. Recently, an editorial in the British Medical Journal suggested that ARBs may increase the risk of myocardial infarction.

Nebivolol (Bystolic - Forest) is a new beta-blocker that has been approved by the FDA for treatment of hypertension. It has been marketed in Europe since 1999 for treatment of hypertension and heart failure.

Some classes of drugs include so many agents that hospital formulary committees, managed care organizations and individual practitioners may find it difficult to choose among them. Fifteen beta-adrenergic receptor antagonists (beta-blockers) are now marketed for systemic use in the USA. One or more have been approved by the FDA for use in hypertension and eight other indications.

- Merck; Zestril - Stuart), a new angiotensin-converting enzyme (ACE) inhibitor, was recently approved by the US Food and Drug Administration (FDA) for once-daily treatment of . Two other ACE inhibitors, captopril (Capoten - Squibb) and e

Losartan potassium (Cozaar - Merck), the first angiotensin II receptor antagonist, has been approved for oral treatment of hypertension by the US Food and Drug Administration. It will be marketed both alone and in a fixed-dose combination with the diuretic hydrochlorothiazide (Hyzaar).

Nicardipine (Cardene - Syntex), a dihydropyridine calcium-entry blocker structurally related to nifedipine (Procardia; Adalat), was recently approved by the US Food and Drug Administration for oral treatment of angina and hypertension. Advertisements for the drug claim that nicardipine is more vasoselective; than other calcium-channel blockers and does not depress myocardial contractility.