Losartan

Additional information

Pharmacokinetics and dosing

In a pharmacokinetic study, single oral and intravenous doses of losartan produced plasma concentrations of losartan that were two-fold higher in hypertensive women than in hypertensive men, due to reduced systemic clearance in women. However, plasma concentrations of the active metabolite of losartan, E 3174 (ten times more effective than the parent compound), were similar in men and women [1-4]. Even though some pharmacokinetic sex differences of losartan have been described, the clinical relevance of these has not been shown and therefore no dosage adjustment based on sex has been considered necessary [3].

Effects

A review evaluating clinical experience with losartan from worldwide, double-blind, controlled studies, confirm that the antihypertensive effect of losartan is similar in women and men [1, 3-6]. The large randomized, triple-blind LIFE study (4230 men, 4963 women) compared losartan with atenolol for reducing cardiovascular morbidity and mortality in patients, aged 55-80 years, with hypertension and left ventricular hypertrophy. Treatment effect of losartan (50 mg daily) was similar in men and women. A sex difference in the primary composite end point (cardiovascular mortality, stroke, and myocardial infarction) was observed, regardless of treatment with losartan or atenolol [7].

A clinical trial reported that women had less regression of electrocardiographic left ventricular hypertrophy than men during losartan therapy. Regression of ECG left ventricular hypertrophy is associated with improved prognosis. These findings suggest that women may derive less prognostic benefit [8].

Adverse effects

Reviews and meta-analysis consisting of several double-blind trials have reported that the overall incidence of adverse clinical events in losartan-treated patients was similar in men and women [5, 6]. In the LIFE study, women had more adverse events than men, regardless of treatment with losartan or atenolol. Serious adverse events (i.e. events causing hospitalization, prolongation of hospitalization, or death) did not differ between men and women (38.3% vs. 36.3%) [7].

Reproductive health issues

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