Labetalol

Additional information

Pharmacokinetics and dosing

A randomized, crossover study (14 men, 5 women) evaluated the impact of patient’s sex on labetalol kinetics. Patients had labetalol dosages titrated from 100 mg twice/day to a specific antihypertensive response. Despite receiving similar average dosages and having similar body weight, significant sex differences were seen in labetalol kinetics. Oral clearance was higher in men. Plasma concentrations were 80% higher in women than men, but the drug’s effect on blood pressure was similar in men and women. The dose-corrected for AUC for the beta-blocking R,R-labetalol was only 10% higher in women, while AUC for the other stereoisomers were 56-77% higher. Thus, the sex differences in labetalol kinetics seem to be due to differences in active alpha-blocking stereoisomers but not in beta-blocking stereoisomers [1].

Labetalol in women with pregnancy-induced hypertension was found to have shorter serum half-life but similar clearance, as compared with those of non-pregnant hypertensive and normotensive populations [2].

Effects

A small randomized study (14 men, 5 women) has shown that men and women achieved similar blood pressure reduction from labetalol, even though plasma concentration was much higher in women than men [1].

Adverse effects

Labetalol in women with pregnancy-induced hypertension was well tolerated by all patients with no adverse effects reported [2].

Reproductive health issues

Regarding teratogenic aspects, please consult Janusmed Drugs and Birth Defects (in Swedish, Janusmed fosterpåverkan).