Pilot Study of Lofexidine and Methadone Pharmacodynamic Interaction in Methadone Maintained Patients
Status:
Completed
Trial end date:
2012-04-01
Target enrollment:
Participant gender:
Summary
The primary objective of this study is to assess QTc (an interval of the heart rhythm)
interaction effects between lofexidine and methadone. The secondary objectives of the study
are to evaluate the safety and tolerability of lofexidine by evaluating and monitoring
pharmacokinetics (amounts of drug in the blood), vital signs (heart rate and blood pressure)
and adverse events (side effects) when co-administered with methadone; and to describe
effects on opiate withdrawal when lofexidine is introduced following a 50% or 100% methadone
dose reduction, as required to elicit a withdrawal response. The investigators hypothesize
that while both agents are known to prolong the QTc interval, the combination of the drugs
will not create an additive effect which creates a significant safety concern. The
investigators further hypothesize that subjects will be able to tolerate the therapeutic dose
of lofexidine (0.8 mg four times daily) when the methadone maintenance dose is lowered to
elicit withdrawal.