Gender based response to fluoxetine hydrochloride medication in endogenous depression

To determine the gender based response to fluoxetine HCl medication in relation to tryptophan metabolism in depressed patients.

A comparative, analytical study.

Clinical Biochemistry and Psychopharmacology Research Unit, Department of Biochemistry, University of Karachi during the year 2002 to 2003.

Sixteen adults depressed patients who were not having any other major comorbidity were selected from the outpatients department of local psychiatric clinic for the study. They were subjected to a semi-structured interview for associated clinical characteristics and diagnosis of depression according to ICD-10 criteria. A control group of normal health male and female individuals was identified for comparison with the depressed group. All the depressed patients were treated with fluoxetine hydrochloride (Prozac 20 mg/day) for four weeks. Healthy individual's data was compared with the depressed group and evaluated for gender based response to fluoxetine HCl medication.

Significant decreases were found in total tryptophan concentrations (33 %, p<0.01,56%, p<0.01) in depressed male and female patients respectively, in contrast, serum cortisol levels were increased by 68% and 98% in male and female depressed patients respectively as compared to healthy controls. Significant increases (23%, p<0.05) in albumin levels were found in females only. Four weeks treatment of male and female depressed group by Fluoxetine HCL (Prozac) 20 mg/kg/day, increased serum total tryptophan concentrations significantly by 32% (p<0.05) in males and by 83% (p<0.01) in females. Serum-free tryptophan concentrations were increased by 22% (p<0.05) in males only. In contrast serum cortisol concentrations were decreased by 31% (p<0.01) and 45.35% (p<0.01) in males and females respectively.

Increases in tryptophan and decreases in cortisol concentrations were greater in females which may contribute to better response of the drug in females.