Gut motility and transit changes in patients receiving long-term methadone maintenance

Area of Science:

• Gastroenterology
• Pharmacology
• Clinical Research

Background:

• Opioid dependence is a significant public health issue.
• Methadone maintenance therapy is a common treatment for opioid dependence.
• Gastrointestinal side effects, including constipation, are frequently reported by patients on opioid therapy.

Purpose of the Study:

• To investigate gut motility and transit time in opioid-dependent patients undergoing methadone maintenance therapy.
• To quantify oral-cecal transit time (OCTT) in this patient population.
• To assess the prevalence and severity of constipation in patients on long-term methadone.

Main Methods:

• Employed the lactulose hydrogen breath test to measure oral-cecal transit time (OCTT).
• Recruited 19 opioid-dependent volunteers receiving methadone maintenance therapy.
• Collected data on patient-reported constipation symptoms before and during methadone therapy.

Main Results:

• A significant proportion (58%) of patients experienced constipation during methadone therapy.
• Mean OCTT was significantly prolonged (159 ± 49.2 minutes) compared to healthy volunteers (P < 0.01).
• Two patients reported severe constipation, indicating a significant clinical impact.

Conclusions:

• Long-term methadone therapy impairs gastrointestinal motility and transit.
• Tolerance to opioids does not appear to extend to their effects on the gut.
• Patients on methadone maintenance therapy serve as a valuable model for studying opioid-induced gastrointestinal dysfunction and evaluating opioid antagonists.