Orlistat

Additional information

Overweight and obesity are more common among men than women in Sweden (57% and 46%, respectively). This sex difference is still statistically significant after adjustment for age, education level, birth country, and county. Obesity alone have similar prevalence rates among men and women (15% and 16%, respectively). Thus, the sex difference is mainly due to differences in overweight [1]. Relative risks of other diseases in obese men and women may be different; women have higher risk of type 2 diabetes, while men have higher risk of renal failure and COPD [2]. Gastric bypass operations are more common in women than men in Sweden (31 vs 10 per 100 000 inhabitants) [3].

Pharmacokinetics and dosing

After a single dose of 360 mg orlistat in obese/overweight patients (5 men, 3 women) no difference in concentrations of orlistat metabolites in urine was found between men and women [4]. No studies with a clinically relevant sex analysis regarding the dosing of orlistat have been found.

Effects

The only study found with a sex-analysis of orlistat effects was a small RCT study combining orlistat with clozapine or olanzapine (41 men, 22 women). The study showed that men taking orlistat had significant weight-loss over time (16 weeks) but not women or men receiving placebo[5, 6].

The effect of orlistat on eating behavior 17 and 33 months after initial weight loss among patients was evaluated in a RCT (149 men, 157 women). There was no difference between the sexes with regard to change in dietary restraint, disinhibition and binge eating [7].

Adverse effects

Results from a large retrospective cohort study (43 295 men, 150 677 women) examining the risk of colorectal cancer associated with orlistat treatment, showed no evidence of an increased risk in analyses stratified according to patient’s sex [8].

Reproductive health issues

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

Other information

The one-year prevalence of orlistat use was higher among men than women in Taiwan between July 2004 and June 2005 (adjusted OR 0.8 women vs men) (in total 269 men, 791 women; with orlistat 49 men, 132 women) [9].