Clinical Pearls & Morning Reports
The three medications approved by the Food and Drug Administration for the treatment of opioid use disorder are naltrexone, methadone, and buprenorphine. Patients who take methadone may have longer retention in treatment than those who take buprenorphine, and patients who take buprenorphine have longer retention than those who take naltrexone. Read the latest Case Records of the Massachusetts General Hospital here.
Q: Can naltrexone, methadone, and buprenorphine be prescribed in any clinical setting?
A: Prescribing naltrexone does not require special training or licensing, although prescribing injectable intramuscular naltrexone often requires prior authorization from an insurance company or collaboration with a specialty pharmacy. As a treatment for pain, methadone can be prescribed and dispensed in a manner similar to any other opioid pain medication, but as a treatment for opioid use disorder, methadone can be administered to patients outside the hospital only through an opioid treatment program that is licensed and regulated at the federal and state levels. Like naltrexone, buprenorphine can be prescribed in any clinical setting, although to prescribe buprenorphine in an outpatient setting, a waiver must be obtained from the Drug Enforcement Agency after completion of additional training (8 hours for physicians and 24 hours for nurse practitioners and physician assistants).
Q: Which medications for opioid use disorder may precipitate withdrawal symptoms?
A: The initiation of either injectable or oral naltrexone treatment precipitates withdrawal symptoms if the patient has not abstained from opioid use for several days before initiation. In contrast with naltrexone, methadone (a full opioid agonist) is not associated with a risk of precipitated withdrawal, so abstinence before the initiation of methadone treatment is not necessary. Buprenorphine (a partial opioid agonist) can precipitate withdrawal if the patient has not abstained from opioid use for several hours before the first dose and has not begun to have withdrawal symptoms.
A: Urine is a more commonly tested specimen type than oral fluid, since it can easily be obtained noninvasively, with the additional benefit that drugs of interest or their metabolites are often concentrated in it. However, urine testing for drugs of abuse is potentially complicated by deliberate manipulation of the specimen; adulteration, substitution, and dilution can all affect drug detection. Although an abnormal creatinine level, pH, or osmolality can suggest specimen manipulation, these measures are not entirely sensitive or specific. The use of oral fluid for drug testing is also a noninvasive technique and may mitigate the potential for specimen manipulation, since collection of the specimen is observed directly. Testing of oral fluid may be particularly useful in clinical practices in which the prevalence of specimen adulteration is high. Such testing requires a higher degree of technical sophistication, may result in a longer turnaround time, and may not be widely available in local practice settings, but it is offered at reference laboratories.
A: The decision to taper treatment should be initiated by the patient and should be based on the clinical scenario. Tapering therapy at less than 1 year typically results in recurrence of active opioid use. One of the longest observational studies of buprenorphine for the treatment of prescription-opioid use disorder, in which patients were followed for up to 42 months, showed that, although many patients elected to taper off buprenorphine during the follow-up period, the strongest predictor of abstinence at 42 months was continued buprenorphine treatment. Long-term treatment with buprenorphine has powerful benefits.