Transdermal fentanyl in children with cancer pain: feasibility, tolerability, and pharmacokinetic correlates.

OBJECTIVES

(1) To assess the feasibility and tolerability of the therapeutic transdermal fentanyl system (TTS-fentanyl) by using a clinical protocol developed for children with cancer pain. (2) To estimate the pediatric pharmacokinetic parameters of TTS-fentanyl.

METHODS

The drug was administered in open-label fashion; and measures of analgesia, side effects, and skin changes were obtained for a minimum of 2 doses (6 treatment days). Blood specimens were analyzed for plasma fentanyl concentrations. The pharmacokinetics of TTS-fentanyl were estimated by using a mixed effect modeling approach.

RESULTS

Treatment was well tolerated. Ten of the 11 patients who completed the 2 doses continued treatment with TTS-fentanyl. The duration of treatment ranged from 6 to 275 days. The time to reach peak plasma concentration ranged from 18 hours to >66 hours in patients receiving the 25 microg/h patch. Compared with published pharmacokinetic data from adults, the mean clearance and volume of distribution of transdermal fentanyl were the same, but the variability was less.

CONCLUSIONS

Treatment of children with TTS-fentanyl is feasible and well tolerated and yields fentanyl pharmacokinetic parameter estimates similar to those for adults. A larger study is required to confirm these findings and further test the clinical protocol.