Reduction of serum serotonin precursors after veralipride treatment for postmenopausal hot flushes

BJECTIVE: The pathogenesis of hot flushes involves several brain neurotransmitter systems, and changes in serotonin turnover have been hypothesized. Veralipride is an anti-dopaminergic agent that relieves hot flushes and putatively also modulates serotonergic neurons. To further elucidate this relationship, in the present study we evaluated whether administration of veralipride for relief of hot flushes is able to affect serum levels of the serotonin precursor tryptophan in postmenopausal women. METHODS: Twenty-four postmenopausal women were randomly assigned to receive veralipride (100 mg/day) or similar placebo tablets for 3 months (n = 12 per group). Free tryptophan and total tryptophan (free + protein-bound) levels were assayed before and monthly by high pressure liquid chromatography. Data were analyzed with repeated measures ANOVA and Student-Newman-Keuls post hoc test. RESULTS: Relief of hot-flushes was achieved with complete suppression of symptoms after veralipride, but not placebo, treatment. In the veralipride group, total tryptophan levels significantly (p < 0.05) decreased from baseline (11.2 +/- 0.4 microg/ml) to 3 months (8.0 +/- 0.3 microg/ml), as well as free tryptophan concentrations (baseline 2.1 +/- 0.1 microg/ml; after 3 months 1.3 +/- 0.1 microg/ml; p < 0.05). No changes were recorded in the placebo group. CONCLUSION: Women treated with veralipride for relief of menopausal symptoms show a decrease in serum levels of serotonin precursors, suggesting that the brain serotonergic system may be involved in the pathogenesis of postmenopausal vasomotor sympto