Pancuronium bromide: an indirect sympathomimetic agent.

In the dog, pancuronium 0.2 mg/kg increased left ventricular systolic pressure and systemic arterial pressure, but did not change central venous pressure. Repeated doses produced diminishing responses and eventually no change in arterial pressure. After tachyphylaxis was established, a pressor response to pancuronium could be induced by an i.v. infusion of noradrenaline. Desipramine, a noradrenaline blocking agent, prevented the restoration of the pressor effect of noradrenaline. Guanethidine and reserpine abollished the restoration of the pressor response to pancuronium by noradrenaline. These findings are consistent with the hypothesis that pancuronium acts on the postganglionic nerve endings and causes release of noradrenaline.