Comparative haemodynamic alterations induced by pipecuronium and pancuronium

Area of Science:

• Pharmacology
• Cardiovascular Physiology

Background:

• Pipecuronium bromide and pancuronium bromide are neuromuscular blocking agents.
• Understanding their cardiovascular effects is crucial for clinical application.

Purpose of the Study:

• To investigate the haemodynamic effects of pipecuronium bromide and pancuronium bromide.
• To elucidate the mechanisms underlying their cardiovascular actions.

Main Methods:

• Isolated rabbit heart preparations to assess inotropic and chronotropic effects.
• Guinea pig tracheal chain preparations.
• Blood pressure measurements in pentobarbital-anesthetized dogs following intravenous drug administration.

Main Results:

• Pipecuronium bromide induced negative inotropic and chronotropic effects at lower concentrations, with biphasic effects at higher concentrations.
• Pancuronium bromide showed positive inotropic and negative chronotropic effects at lower concentrations, and negative inotropic and chronotropic effects at higher concentrations.
• Cardioinhibitory effects were not attributed to cholinergic or beta-1 adrenergic blockade but suggested a nicotine-like activity.
• Both drugs caused transient decreases in systolic and diastolic blood pressure in dogs at supra-therapeutic doses, indicative of partial ganglion blockade.

Conclusions:

• Pipecuronium bromide and pancuronium bromide exhibit distinct cardiovascular effects.
• The observed cardioinhibitory actions may involve nicotine-like activity.
• A partial ganglion blocking effect contributes to the observed hypotension at higher doses.