Usefulness of serotoninergic challenge with oral citalopram

Challenge tests designed to evaluate serotoninergic pathways have widely used intravenous citalopram. Oral citalopram has also been used, but unsatisfactory results were obtained with a dose of 20 mg. The objective of this study was to determine whether a higher oral dose would reproduce similar to those described for intravenous administration. To that end, we evaluated cortisol, growth hormone and prolactin levels.

Eight healthy male volunteers were evaluated in a randomized crossover challenge test with 40 mg of oral citalopram or placebo.

Cortisol levels increased at 2-4h after the oral citalopram intake, with a small amplitude peak occurring in two-thirds of the subjects. Levels of prolactin and growth hormone remained unchanged throughout the study.

The use of oral citalopram might present an alternative in serotoninergic challenge tests, but higher doses are required.