Liver drug metabolism and blood pressure response to a lipophilic and hydrophilic beta blocker

The role of liver drug metabolism on blood pressure (BP) response to a lipophilic (propranolol) and hydrophilic (sotalol) beta blocker in thirty hypertensive patients was studied. Ten patient treated with diuretics were classified according to plasma antipyrine clearance rate as rapid and slow metabolizers. They were first treated for one month with propranolol and then for one month with sotalol at equivalent dosage. Four patients, classified as rapid drug metabolizers had a better response to sotalol, 139 (SD 13)/92 (SD 6) mmHg, than to propranolol , 164 (21)/104 (10) mmHg. For the other six patients, with slow drug metabolism, the response to propranolol , 142 (8)/95 (8) mmHg was equal to sotalol, 143 (19)/93 (8) mmHg. Twenty patients were randomly divided into two groups. The patients in these groups were similar as to sex, age, body mass index, BP and rate of drug metabolism. The subjects in the first group were treated with propranolol and diuretic and those in the second with sotalol and diuretic. The BP response was equal in both groups, propranolol 147 (14)/96 (7) mmHg and sotalol 143 (12)/95 (9) mmHg after two years’ follow-up. The rate of drug metabolism must be considered when evaluating response t o lipophilic but not to hydrophilic beta blocker.