Evaluation of possible interactions between ethanol and trazodone or amitriptyline

Area of Science:

• Pharmacology
• Neuroscience
• Clinical Psychology

Background:

• Trazodone and amitriptyline are commonly prescribed antidepressants.
• Ethanol (alcohol) is frequently consumed by the general population.
• Interactions between antidepressants and ethanol can affect cognitive and motor functions.

Purpose of the Study:

• To investigate the pharmacodynamic interactions between single doses of trazodone or amitriptyline and ethanol.
• To assess the combined effects on cognitive performance and psychomotor skills.
• To evaluate safety implications for patients taking antidepressants and consuming alcohol.

Main Methods:

• Double-blind, placebo-controlled, crossover study with 6 healthy volunteers.
• Administration of trazodone (100 mg), amitriptyline (50 mg), or placebo, with or without ethanol (0.5 ml/kg).
• Assessment of pharmacodynamic effects using critical flicker fusion frequency threshold (CFF), choice reaction time (CRT), manual dexterity, digit span test, and visual analogue scales.

Main Results:

• Ethanol did not alter blood ethanol concentrations or significantly affect most pharmacokinetic parameters of trazodone and amitriptyline.
• Both trazodone and amitriptyline induced significant depressant effects on CFF, CRT, and manual dexterity, and altered subjective ratings.
• Ethanol alone impaired manual dexterity and increased drowsiness; combined use further impaired manual dexterity but showed limited additional effects on other measures.

Conclusions:

• The combination of ethanol with trazodone or amitriptyline did not produce additive profound effects on most measured cognitive and psychomotor parameters.
• Manual dexterity was notably more impaired when ethanol was combined with either antidepressant.
• Results suggest caution for patients on antidepressant medication regarding concurrent ethanol consumption due to potential risks, particularly to motor skills.