Ranitidin

Additional information

Pharmacokinetics and dosing

One study has investigated if pharmacokinetic parameters of a single dose oral ranitidine differ in men and women in different phases of the menstrual cycle. Healthy volunteers (10 men, 10 women) received a single dose of 300 mg ranitidine. Differences were seen in women at different stages of the menstrual cycle. In the follicular phase distribution volume and total clearance was lower while AUC and maximum concentration was higher than in the luteal phase. Men had 56% higher AUC and 9% lower clearance than women in their follicular phase [1]. Another study, without considering the phase of the menstrual cycle, found no sex differences in ranitidine pharmacokinetics in patients (8 men, 8 women) receiving 300 mg ranitidine [2]. Despite the pharmacokinetic differences of ranitidine, the clinical studies have shown effect with similar doses in men and women and no sex differentiation in dosing has been suggested [3].

Effects

A randomized, double-blind, placebo-controlled trial (99 men, 127 women) showed that 150 mg ranitidine for 48 weeks was more effective in maintaining healed gastric ulcers compared with placebo, in both men and women [4]. A case-controlled clinical trial in patients (63 men, 17 women) with giant gastric ulcer receiving ranitidine 300 mg daily for 8 weeks showed that healing rates were not related to sex [5].Recurrence of duodenal ulcer after withdrawal of long-term treatment with ranitidine has been analyzed in several studies. A single-blind study found that women had lower relapse rates than men at 12 months (80% vs. 92%) [6] while other, randomized, placebo-controlled studies have not found sex to be a risk factor for recurrence [7, 8].

Adverse effects

No studies with a clinically relevant sex analysis regarding adverse effects of ranitidine have been found.

Reproductive health issues

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