[Falipamil for decreasing intraoperative heart rate in pheochromocytoma]

In 4 patients (2 males, 2 females), aged between 16 and 62 years, who had surgery for pheochromocytoma, the effects of Falipamil, a compound with selective negative chronotropic action, was tested. This drug, which is a slow calcium channel blocking agent, was administered during the period of massive endogenous catecholamine output caused by tumor mobilisation; the influence on mean arterial pressure, pulmonary artery pressure, central venous pressure and cardiac index as well as catecholamines was investigated. When the pulse rate exceeded 100 beats per minute in the course of surgical preparation, 2 mg/kg BW Falipamil were administered as in i.v. bolus dose. Epinephrine and norepinephrine were determined before and 5 minutes after Falipamil administration in one patient. The effect of this bolus dose was a significant decrease in heart rate. There was also a moderate decrease in mean arterial pressure and cardiac index, with was probably caused by pretreatment with alpha- and beta-blockers prior to surgery, whereas central venous pressure and pulmonary artery pressure remained unchanged. Norepinephrine increased, epinephrine decreased. These findings lead us to conclude that Falipamil is a valuable adjunct to control circulation in patients with high catecholamines.