ATC code: N03AX12
Controlled studies on differences between men and women in efficacy of gabapentin regarding epileptic seizures or neuropathic pain are lacking but estimates from response in clinical studies do not indicate any significant differences.
Reported information about pharmacokinetic differences between men and women is conflicting but are not considered to be of clinical relevance.
Population data analyses indicate that the pharmacokinetic parameters for men and women are similar [1, 2]. One small clinical trial evaluated the effect of patient’s sex on the pharmacokinetics of gabapentin (18 men, 18 women). Following a single 400 mg oral dose gabapentin, Cmax was about 25% higher for women than for men, probably due to a smaller volume of distribution in women, as a result of their generally smaller size. However, the sex difference in Cmax values is not considered to be clinically important. The apparent elimination rate constant declined with increasing age for women but did not reach significance in relation with age for men. Since the relation between the apparent oral clearance and age was similar for men and women, the sex difference in relation between apparent elimination rate constant and age may be due to a sex-related difference in the relation between volume of distribution and age [3]. No sex differentiation in dosing has been recommended by the pharmaceutical company [4]. Individual dose-titration is recommended for all indications in both men and women.
No published studies with a clinically relevant sex analysis regarding the effects of gabapentin in epilepsy or neuropathic pain have been found. Estimates of response to gabapentin in epilepsy derived from clinical trials (398 men, 307 women) indicate no appearant sex differences [1].
According to the pharmaceutical company, adverse effects were more common in men than in women [2], but studies with a clinically relevant sex analysis regarding adverse effects of gabapentin have not been published.
Regarding teratogenic aspects, please consult Janusmed Drugs and Birth Defects (in Swedish, Janusmed fosterpåverkan).
Updated: 2020-08-28
Date of litterature search: 2019-08-28
Reviewed by: Mia von Euler, Carl-Olav Stiller
Approved by: Karin Schenck-Gustafsson