Amitriptyline and weight gain: a biochemical and endocrinological study

Area of Science:

• Pharmacology
• Endocrinology
• Metabolic Research

Background:

• Weight gain is a potential side effect of amitriptyline.
• This study investigated if hypoglycemia, driven by increased insulin, underlies amitriptyline-induced weight gain.

Purpose of the Study:

• To test the hypothesis that amitriptyline causes weight gain via insulin-mediated hypoglycemia.
• To assess the impact of amitriptyline on glucose and insulin regulation in healthy individuals.

Main Methods:

• Six healthy volunteers received 50 mg of amitriptyline twice daily for 28 days.
• Serum levels of amitriptyline and nortriptyline were monitored.
• Glucose tolerance tests and insulin level measurements were performed on days 0, 14, and 28.

Main Results:

• Amitriptyline and nortriptyline reached steady-state serum levels by day 10.
• No significant weight gain was observed, though appetite increased in two subjects.
• No significant differences were found in glucose tolerance, fasting/peak insulin, or glucose/insulin ratios.

Conclusions:

• Amitriptyline treatment did not induce hypoglycemia or significant weight gain in this cohort.
• The proposed mechanism of insulin-mediated hypoglycemia does not explain weight gain associated with amitriptyline in healthy volunteers.