Which of the following anti-epileptic drugs is known for being weight negative?

Topiramate is recognized for its weight-negative effects among the listed anti-epileptic drugs. It has been studied for its potential to induce weight loss, which can be particularly beneficial for patients who may be concerned about weight gain as a side effect of their epilepsy treatment.

The mechanisms by which topiramate promotes weight loss include appetite suppression and increased energy expenditure. This is in contrast to other anti-epileptic medications, which may be associated with weight gain. For example, valproate is known for causing significant weight gain, often due to increased appetite and changes in metabolism. Gabapentin can lead to weight gain as well; its structure and effects on the central nervous system can contribute to increased appetite in some patients. Lamotrigine is generally weight-neutral, as it does not show a clear predisposition towards weight gain or loss, but it is not typically classified as weight-negative like topiramate.

Thus, topiramate stands out for its unique property of promoting weight loss in patients who are being treated for epilepsy, making it a suitable choice for those who are overweight or at risk of weight gain from other medications.