What is a common side effect of carbamazepine?

Hyponatremia is a known common side effect of carbamazepine, which is an antiepileptic medication also used in the treatment of bipolar disorder and trigeminal neuralgia. The mechanism behind this side effect involves the drug's effect on the regulation of sodium levels in the body. Carbamazepine can cause the inappropriate secretion of antidiuretic hormone (ADH) or it can lead to the syndrome of inappropriate antidiuretic hormone secretion (SIADH), which ultimately results in a dilutional form of hyponatremia.

Monitoring sodium levels in patients on carbamazepine is crucial, particularly in older adults or those on other medications that might affect sodium balance. Recognizing this side effect is important because it can lead to serious complications if not addressed promptly.