Labetalol in long-term treatment of hypertension.

1 Labetalol, a beta- and alpha-adrenoreceptor-blocking drug, has been used in the treatment of hypertension in a total of 32 patients for over 4.5 yr, 14 patients for 3 yr or more. 2 Labetalol seems to have a similarly potency of methyldopa and the adrenergic neurone-blocking drugs. 3 Postural hypotension was only observed at doses over 2 g/d. It was the reason for stopping treatment in two patients. 4 Dosage varied; average 889 mg/d, range 75-3,200 mg. Tolerance did not develop. 5 Side-effects led to drug withdrawal in four patients