[Changes in hepatic biotransformation in patients treated with beta-adrenergic drugs and prazosin].

Biotransformation in the liver was tested with antipyrine elimination test in 41 patients treated with prazosin for 3 months (Minipress Pfizer, 1-4 mg a day) or prazosin combined with beta-adrenolytic agents (propranolol 40-80 mg; metoprolol 100-200 mg daily). It was found that T0.5 of antipyrine is shortened in patients treated with prazosin alone by 3 h/p greater than .05/while in the patients treated with prazosin whom previously--adrenalytics were given by 7.5 h/p greater than 0.01/. Antipyrine half-life during the treatment with beta-adrenolytics was prolonged by + 5.3 h/p greater than .05/while during the combined therapy with these agents and prazosin - 3.8 h. These results indicate that prazosin contrary to beta-adrenolytics, does not affect biotransformation in the liver. During combined therapy with prazosin and beta-adrenolytics, unfavourable effect of the latter in prevailing. Replacement of beta-adrenolytics with prazosin may prevent unfavourable effect of the former on liver functioning and may increase the safety of the hypotensive treatment.