Paroxetines Effect on Tramadols Metabolism and Pharmakodynamics: a Dose Response Study
Status:
Unknown status
Trial end date:
2009-02-01
Target enrollment:
Participant gender:
Summary
The purpose of the study is to examine the connection between the dose of paroxetine and the
effect of paroxetine on tramadols metabolism and thereby the effect of tramadol on the median
pupil size.
In the study 12 healthy volunteers are going through 5 phases where they are suppose to
consume a determined dose of tramadol and 5 various doses of paroxetine corresponding to the
5 phases. Fig 1.
phases 1 2 3 4 5 Dosis Tramadol mg 50 50 50 50 50 Dosis Paroxetine mg Placebo 10 20 30 50
Paroxetin / placebo 2 ½ placebo 2 placebo 1 ½ placebo 1 placebo tablets ½ paroxetine 1
paroxetine 1 ½ paroxetine 2 ½ paroxetine Fig. 1 summary of the 5 phases
There is a variation in the time where maximal plasma concentration is obtained in
consumption of respectively tramadol (1 - 2 hours) and paroxetine (6 hours). For that reason
there has to be at least 6 hours between the administration of paroxetine and tramadol.
The healthy volunteer brings the research medicine home and consumes it before bedtime the
night before the day of the study. At eight o'clock next morning the healthy volunteer
arrives to the first pupil measurement and consumption of tramadol. Tree hours later the next
pupil measurement is carried through. The healthy volunteer accumulates his or her urine
until 2 pm. As paroxetine is a irreversible inhibitor of the enzyme CYP2D6 there has to go at
least 14 days before the next phase takes place. In that amount of time there can be
recreated a new pool of enzyme.