Feasibility Study of Oral Naloxone for Treatment of Methadone-induced Constipation
Status:
Completed
Trial end date:
2015-03-01
Target enrollment:
Participant gender:
Summary
At least 30% of patients receiving methadone maintenance therapy (MMT) are suffering from
constipation that often affects effectiveness of MMT and increases its impact on health care
system. Existing treatments include several over-the-counter medications which do not target
the pathobiological basis of opioid-induced constipation and have limited effectiveness. At
the same time well-known medication, naloxone, was already shown to help with constipation in
patients receiving methadone for chronic pain, but was never tried in patients receiving
methadone for opioid dependence. This study is aimed to try naloxone for treatment of
opioid-induced constipation in MMT settings.
The investigators will enroll 20 patients receiving MMT and suffering from opioid-induced
constipation. The study has a crossover design - all patients will receive one week of their
regular methadone doses and one week of their regular methadone doses with naloxone added.
Normal saline will be added to methadone-only formulations as placebo. Order of the weeks
will be chosen randomly. Both subjects and investigators will be blinded to the study
condition (i.e. whether naloxone or normal saline is added to methadone preparation on a
given week).
Primary hypothesis: Patients receiving combination of oral methadone/naloxone in ratio 50:1
will have less severe symptoms of constipation compared to those receiving methadone only.
Secondary hypothesis: Addition of oral naloxone to methadone in a ratio 50:1 will not cause
clinically significant opioid withdrawal symptoms.