Topiramate

Topiramate is a medication originally used to treat epilepsy and prevent migraines. It was observed that patients taking topiramate often lost weight, leading to its use in weight management — usually combined with phentermine as the branded medication Qsymia. It works by reducing appetite and making food less rewarding.

Topiramate is a sulphamate-substituted monosaccharide with multiple mechanisms of action including voltage-gated sodium channel blockade, GABA-A receptor potentiation, and AMPA/kainate glutamate receptor antagonism. Its weight-loss effects are thought to be mediated through appetite suppression, reduced binge-eating behaviour, and possibly increased energy expenditure. It is approved in combination with phentermine (Qsymia) for chronic weight management, with clinical trials demonstrating 8–10% total body weight loss at one year.

For patients who do not respond to or cannot tolerate GLP-1 receptor agonists, topiramate-containing regimens offer an alternative pharmacological option. Dr Joseph Wang assesses each patient’s full medical profile to determine whether topiramate-based therapy is appropriate, given its potential cognitive side effects.