title: Obstructive sleep apnea and tricyclic antidepressant use presenting as a pseudopheochromocytoma in an active duty sailor: a case report.
abstract: A 36-year-old active duty male with migraine headaches presented for evaluation of poorly controlled hypertension. The workup included an endocrinological examination, which revealed a moderately elevated urine normetanephrine level, suggesting the possibility of a pheochromocytoma. The evaluation also included a sleep study for possible obstructive sleep apnea (OSA) because of a history of snoring, apneic episodes, and daytime somnolence. The sleep study confirmed the diagnosis of OSA. The patient was treated with continuous positive airway pressure therapy and a plasma normetanephrine level demonstrated improvement, but persistent elevation. The patient was noted to be taking amitriptyline for migraine headache prevention. With approval from Neurology, the medication was discontinued and a repeat urine normetanephrine level revealed normalization. This case demonstrates the well-documented medication-associated false-positive test result that can be seen in patients taking tricyclic antidepressants. Tricyclic antidepressants, along with phenoxybenzamine, account for 41 to 45% of all elevated metanephrine and normetanephrine levels in patients without pheochromocytoma. This case also shows that patients with OSA can develop hypertension through elevated sympathetic tone, mimicking a pheochromocytoma. Treatment with continuous positive airway pressure therapy is recommended to not only improve hypertension and catecholamine excess but also distinguish the condition from a pheochromocytoma.
authors.affiliation: Medical Readiness Division, Naval Surface Force Pacific, 3985 Cummings Road, San Diego, CA 92136.
authors.forename: Tamara
authors.initials: T
authors.lastname: Brainard
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000175:diagnosis* / Q000652:urine; D000328:Adult; D000639:Amitriptyline / Q000009:adverse effects*; D000929:Antidepressive Agents, Tricyclic / Q000009:adverse effects*; D003937:Diagnosis, Differential; D006801:Humans; D006973:Hypertension / Q000209:etiology; D008297:Male; D008881:Migraine Disorders / Q000150:complications / Q000188:drug therapy; D008889:Military Personnel; D009326:Naval Medicine; D009647:Normetanephrine / Q000652:urine; D010673:Pheochromocytoma / Q000175:diagnosis* / Q000652:urine; D020181:Sleep Apnea, Obstructive / Q000150:complications* / Q000175:diagnosis
chemical_list: D000929:Antidepressive Agents, Tricyclic; D009647:Normetanephrine; D000639:Amitriptyline