Abstract: Objective To explore the adverse reactions and influencing factors of hyponatremia caused by venlafaxine and provide reference for safe clinical use of venlafaxine. Methods One case of hyponatremia caused by venlafaxine hydrochloride sustained-release capsules was analyzed and medications were recommended after related literature was reviewed. Results One patient who had been treated with venlafaxine for vestibular migraine for five years developed recurring hyponatremia. After discontinuation of venlafaxine and sodium supplementation therapy, the serum level of sodium gradually returned to normal, suggesting that venlafaxine had caused hyponatremia. Conclusion Venlafaxine is widely used in the treatment of depression. Doctors should be alert to the risk of hyponatremia caused by venlafaxine, have a good knowledge of the indications, contraindications, drug interactions and treatment courses of venlafaxine, and use this drug cautiously among such vulnerable populations as the elderly, females, those using diuretics, and those with a history of hyponatremia. Regular monitoring of electrolytes during medication, starting with small doses, early detection, and management of adverse drug reactions are essential to patients’ safety during medication.

Key words: venlafaxine, selective serotonin reuptake inhibitor, antidepressant, hyponatremia, syndrome of inappropriate antidiuretic hormone, adverse drug reaction