Drug General Information (ID: DDIAGBJL0T)
  Drug Name Methadone Drug Info Didanosine Drug Info
  Drug Type Small molecule Small molecule
  Therapeutic Class Analgesics Anti-Hiv Agents
  Structure

 Mechanism of Methadone-Didanosine Interaction (Severity Level: Major)
     Increased risk of other adverse reactions (Unspecific) Click to Show/Hide Mechanism Graph
      Drug Name Methadone Didanosine
      Mechanism Delay absorption and bioavailability of didanosine Didanosine
      Key Mechanism Factor 1
Factor Name Adverse reactions
Factor Description An adverse reaction is an unexpected negative reaction to a medication or treatment that happens even when it's used correctly.
      Mechanism Description
  • Increased risk of adverse reactions by the combination of Didanosine and Methadone 

Recommended Action
      Management Given the risk of reduced viral susceptibility and resistance development associated with subtherapeutic antiretroviral drug levels, didanosine pediatric powder should not be prescribed in combination with methadone. If coadministration of didanosine and methadone is necessary, the recommended formulation of didanosine is the enteric-coated, delayed-release formulation (Videx EC). Patients should be closely monitored for adequate clinical response when Videx EC is coadministered with methadone, including monitoring for changes in viral load.

References
1 Foster DJ, Somogyi AA, Bochner F "Methadone N-demethylation in human liver microsomes: lack of stereoselectivity and involvement of CYP3A4." Br J Clin Pharmacol 47 (1999): 403-12. [PMID: 10233205]
2 Product Information. Videx (didanosine). Bristol-Myers Squibb, Princeton, NJ.
3 Rainey PM, Friedland G, McCance-Katz EF, et al. "Interaction of methadone with didanosine and stavudine." J Acquir Immune Defic Syndr. 2000;24(3):241-248..[PMID: 10969348]