Dose-response relation for atracurium, ORG NC 45 and pancuronium

Area of Science:

• Pharmacology
• Anesthesiology
• Neuromuscular Blockade

Background:

• Neuromuscular blocking agents are crucial in anesthesia for facilitating endotracheal intubation and surgical procedures.
• Understanding the comparative potencies and effects of different neuromuscular blocking agents is essential for safe and effective clinical practice.

Purpose of the Study:

• To compare the potencies and intubating conditions of atracurium, Org NC 45, and pancuronium.
• To evaluate the hemodynamic effects (arterial pressure and heart rate) of these neuromuscular blocking agents.

Main Methods:

• Cumulative dose-response curves were utilized to determine drug potencies.
• Log-probit analysis was applied to analyze dose-response curve slopes.
• Intubating conditions and hemodynamic parameters were assessed at 95% twitch depression.

Main Results:

• The effective doses for 95% twitch depression were 279 µg/kg for atracurium, 56 µg/kg for Org NC 45, and 64 µg/kg for pancuronium.
• Relative potencies were determined as 1:5.0:4.3 for atracurium:Org NC 45:pancuronium.
• Pancuronium exhibited the steepest dose-response curve slope. All drugs provided good intubating conditions at 95% twitch depression.
• Pancuronium resulted in greater increases in arterial pressure and heart rate compared to atracurium and Org NC 45.

Conclusions:

• Org NC 45 is significantly more potent than atracurium, and pancuronium is also more potent than atracurium.
• All three neuromuscular blocking agents offer comparable and adequate intubating conditions.
• Pancuronium has a more pronounced effect on cardiovascular parameters than atracurium and Org NC 45.