Topiramate also known as Topamax is classified as an anticonvulsant (seizures) prescription drug that is mainly used as an epilepsy therapy. It is also approved for migraine therapy and as an adjunct to Phentermine for weight loss. Off-label uses include therapy for bipolar and borderline personality disorders and weight loss.
Even though Topiramate has been demonstrated to reduce the prevalence of seizures, the underlying mechanism is not well understood. Some researchers think that Topiramate alters voltage-gated sodium channels as well as calcium channels. Others think that it may affect GABA receptors, AMPA receptors and carbonic anhydrase isoenzymes.
No matter how Topiramate works, a number of individuals have been prescribed this drug and had success in losing weight. However, it is not approved as a standalone drug for weight loss. It is approved for weight loss when coupled with Phentermine as in Qsymia.
Possible Weight loss Mechanisms For Topiramate
- Addiction Centers – this drug may be targeting addiction centers of the brain. It has been observed that patients that previously looked for pleasure-inducing substances such as food, alcohol and drugs no longer did so when taking Topiramate. It may inhibit overexcited neurons in this region bringing back balance.
- Appetite suppression – patients experience a loss in appetite as a side effect of this drug. Recall, it is an anticonvulsant. Some believe that Topiramate is interacting with the rewards centers of the brain altering the way rewards are processed. This may lead to patients feeling less hungry.
- Hormonal changes – Some feel that it may be altering hormone levels such as cortisol and leptin. Leptin is known as the satiety hormone (tells you to stop eating because you are full). It is made by fat cells that help regulate energy balance by inhibiting hunger. Leptin is opposed by the actions of the hormone ghrelin. Ghrelin is known as the hunger hormone. Together they regulate appetite. In obesity, there is a decreased sensitivity to leptin such that they have an inability to detect satiety even though they have high energy (fat) stores.
- Confusion – patients have reported that they feel disoriented on Topiramate and that they have trouble remembering to eat. This drug does have a potent effect on memory making some people feel dizzy and confused.
- Ketosis – it is believed that Topiramate affects levels of blood glucose and insulin possibly leading to ketosis. Ketosis is a state where the body uses its own fat to make energy allowing for incredible weight loss. Low carb diets such as Atkins do this. So, it may be that Topiramate may artificially induce ketosis.
- Taste Alterations – patients report a loss of pleasurable taste. So, people eat smaller portions because the food just isn’t that tasty (interesting). Some patients have reported bad tastes on this drug. Saliva – this drug causes a reduction in saliva production. This in itself can cause poorer taste sensation which generally reduces appetite which leads to weight loss.