Abstract
In the present study, we report a case of pheochromocytoma whose high blood pressure was well controlled by single-agent therapy with longacting nifedipine, in spite of the failure of the combination of labetalol and prazosin in lowering blood pressure satisfactorily. A 48 year old female was first noted to have hypertension (160/100mmHg) at 45 years of age. Hypertension was not controlled by conventional antihypertensive drugs. She was admitted to Fukui Prefectural Hospital in September, 1985. Her blood pressure on admission was 210/110mmHg. Extraction of the left adrenal gland containing a pheochromocytoma (30×37×10mm) was performed in November, 1985. Her hypertension and abnormally high plasma noradrenaline (NA) concentration (1, 760pg/ml, normal value 40-350pg/ml) were sustained even after operation. Combination therapy with labetalol (400mg/day) and prazosin (6mg/day) was unsatisfactory, and the addition of long-acting nifedipine (40mg/day) produced a marked decrease in blood pressure. Furthermore, single therapy with longacting nifedipine was effective. No reduction of urinary NA excretion was observed in our patient during long-acting nifedipine therapy, suggesting that the decrease in blood pressure was not caused by suppression of NA release from pheochromocytoma tissue.
