Topic: Clinically Relevant Drug Interactions: Buprenorphine or Methadone with Other Frequently Prescribed Drugs

Topic: Clinically Relevant Drug Interactions: Buprenorphine or Methadone with Other
Frequently Prescribed Drugs

Author: Elinore F. McCance-Katz, M.D., Ph.D.

Last Updated: 9/24/10


Clinical questions:
1. What drug interactions of clinical significance occur between buprenorphine or
methadone and other medications?
2. In thinking about opioid therapy for an opioid dependent patient, how can I determine
whether to select methadone or buprenorphine as the treatment medication?
Background:
Drug interactions are a leading cause of morbidity and mortality. Methadone and
buprenorphine are frequently prescribed for the treatment of opioid addiction. Patients
needing treatment with these medications often have co-occurring medical and mental
illnesses that require medication treatment. The abuse of illicit substances is also
common in opioid-addicted individuals.

These clinical realities place patients being treated with often have co-occurring medical and mental illnesses that require medication treatment. The abuse of illicit substances is also
common in opioid-addicted individuals. These clinical realities place patients being
treated with methadone and buprenorphine at risk for potentially toxic drug interactions.

A substantial literature has accumulated on drug interactions between either methadone
or buprenorphine with other medications when ingested concomitantly by humans. This
guidance will summarize that literature in tabular form below (Adapted from Reference 1
below).



                         

No clinically significant interaction
 
Didanosine (in tablet form)

• Significant decrease in didanosine   HIV Medications   
• concentrations of methadone, AZT and Suboxone/Subutex
• Not studied in human pharmacokinetics studies methadone

Stavudine

• Significant decrease in stavudine concentrations  HIV Medications
• Not studied in human pharmacokinetics studies

Delavirdine 

• Increased methadone (and LAAM)  
• concentrations; no cognitive impairment  HIV Medications
• Increased buprenorphine concentrations; no cognitive impairment

Atazanavir 

• Not associated with increased levels of methadone
• Significant increases in buprenorphine and report of cognitive dysfunction
• under study    HIV Medications

Darunavir 

• Opiate withdrawal may occur
• Under study

Efavirenz

• Opiate withdrawal may occur
• No clinically significant interaction

Fosamprenavir

• Data suggest that the PK interaction is not clinically relevant; 
• however, patients should be monitored for opiate withdrawal symptoms

Under study
Nelfinavir 

• Methadone levels are decreased. Opiate withdrawal may occur
• No clinically significant interaction

Nevirapine

• No clinically significant interaction
• Opiate withdrawal may occur

Lopinavir/ritonavir 

• Opiate withdrawal may occur
• No clinically significant interaction

http://pcssb.org/wp-content/uploads/2010/09/PCSS-B-Opioid-Therapies-and-Drug-Interactions.pdf