Paroxetine oral solution is bioequivalent to paroxetine tablets--advantages of the solution

This study was undertaken to compare the pharmacokinetic profiles of paroxetine oral solution and paroxetine tablets in healthy volunteers under fasting conditions.

In this randomized, open-label, single-dose, 2-way cross over, laboratory-blind bioequivalence study healthy volunteers alternately received one 20 mg dose paroxetine as an oral solution (20 mg/20 drops) and one 20 mg dose paroxetine as a tablet. Doses were separated by a 23-day interval.

A total of 48 subjects enrolled in the study; there were 26 males and 22 females with a median age of 25.5 years and a median weight of 73.6 kg. Both formulations were well tolerated, with no serious adverse events reported. Two subjects discontinued the study. Paroxetine was rapidly absorbed, the rate and extent of absorption of the two formulations were similar, and no statistically significant differences in half-life were observed between formulations.

The oral solution and tablet formulations of paroxetine were bioequivalent and therefore may be safely interchanged. The oral solution may be a useful tool to ease administration and for tapering off paroxetine treatment.