Lidocaine and amitriptyline interaction during experimental haemoperfusion.

Area of Science:

• Pharmacology
• Toxicology
• Cardiovascular Physiology

Background:

• Amitriptyline overdose can cause severe cardiovascular complications.
• Hemoperfusion (HP) is a potential treatment for drug intoxication.
• Lidocaine is sometimes used to manage cardiac arrhythmias in amitriptyline toxicity.

Purpose of the Study:

• To investigate the efficacy of lidocaine in enhancing amitriptyline removal during HP.
• To assess the effect of lidocaine on myocardial performance in amitriptyline-intoxicated dogs during HP.
• To determine the distribution and metabolism of amitriptyline during HP.

Main Methods:

• Hemoperfusion (HP) was performed on five beagle dogs with induced amitriptyline intoxication.
• Lidocaine was administered to assess its displacement effect on amitriptyline clearance.
• Cardiac function was monitored, and drug concentrations were measured in blood and tissues post-necropsy.

Main Results:

• Lidocaine did not significantly improve amitriptyline removal during HP (2% of dose removed).
• Lidocaine clearance during HP was high (0.99), with 13% removed.
• Highest amitriptyline concentrations were in the brain and lungs; liver and lungs showed the lowest amitriptyline/nortriptyline ratio, indicating metabolism.

Conclusions:

• Lidocaine does not enhance amitriptyline removal via hemoperfusion.
• Lidocaine does not improve cardiac function in amitriptyline-intoxicated dogs during HP.
• The liver and lungs are significant sites for amitriptyline metabolism.