In their study, featured in the Addiction journal on the 4th of August 2023, the authors recommend that doctors refrain from co-prescribing opioid agonists like methadone or buprenorphine with benzodiazepines, gabapentinoids, antipsychotics, or Z-drugs, unless the potential benefit to patients clearly outweighs the risks.
Opioid agonists, which encompass substances such as methadone and buprenorphine, are employed as a substitute for illicit drugs in the treatment of individuals grappling with drug dependency, particularly heroin.
This investigation, supported by the National Institute for Health and Care Research (NIHR) Greater Manchester Patient Safety Translational Research Centre, undertaken in partnership between The University of Manchester and the Northern Care Alliance NHS Foundation Trust, examined the medical records of 20,898 individuals undergoing opioid agonist treatment.
The study found that those who were prescribed benzodiazepines—commonly used sedatives—exhibited a 1.45-fold increase in the likelihood of hospital admission due to overdose when compared to those not prescribed such medications.
When gabapentinoids, employed for various conditions including neuropathic pain, epilepsy, and anxiety disorders, were combined with opioid agonists, the risk of hospital admission for overdose rose by a factor of 2.2.
Similarly, the likelihood of overdose-related hospitalization was 1.6 times higher when Z-drugs, also sedatives, were prescribed alongside opioid agonists. Additionally, antipsychotics, used to address psychosis, increased the overdose risk by a factor of 1.85.
However, the researchers did not identify any increased risk associated with the co-prescription of antidepressants.
The study observed primary care patients in England, aged between 18 and 64 years, who were grappling with opioid use disorder. The data encompassed 15,155 individuals prescribed methadone and 5,743 prescribed buprenorphine between January 1998 and December 2017.
Opioid use disorder is characterized by cravings for opioids, persistent use despite physical or psychological deterioration, heightened tolerance, and withdrawal symptoms.
The research data was sourced from the Clinical Practice Research Datalink GOLD and Aurum databases, and subsequently linked with information from the Hospital Episode Statistics and the Office for National Statistics.
Existing knowledge indicates that methadone, functioning as a full opioid agonist, can trigger overdose at high doses, while buprenorphine, a partial opioid agonist, appears to pose a lower risk.
Nevertheless, both treatments may interact with other commonly prescribed medications for individuals dealing with opioid use disorder.