Severe Resistant Hypertension Induced by Carbamazepine in an Elderly Patient

We report a case of a 73-year-old patient with a 17 year-history of well-controlled primary hypertension with a single antihypertensive drug, which became uncontrolled since 9 months ago when he started on oral carbamazepine (CBZ) therapy for syringomyelia. On admission, the patient had a blood pressure of 200‒215/95‒104 mmHg despite an antihypertensive combination therapy with five different drugs. Further investigations ruled out secondary hypertension such as primary aldosteronism, pheochromocytoma and renal artery stenosis. After the discontinuation of CBZ, the blood pressure profile became significantly improved. The rechallenge with CBZ aggravated his blood pressure profile. Therefore, we considered that resistant hypertension was induced by the oral CBZ therapy.