How Illicit Fentanyl Affects Buprenorphine Induction
The landscape of black market opioids has seen some pretty major changes over the years.
An influx of illegally manufactured fentanyl has infiltrated the heroin market, and has even been found in other street drugs like cocaine and pressed pills, leading to an uptick in overdose deaths that have been described by some as an “epidemic” or “crisis.” When produced for pharmaceutical purposes, fentanyl is a powerful, fast-acting opioid administered for acute breakthrough pain that can’t be managed with less potent opioids like morphine. It is sometimes used during child labor, for example, or during hospice care for terminally ill patients. But the formulations showing up in street drugs are not pharmaceutical fentanyl, meaning you can’t count on them to have the same properties as the fentanyl that’s prescribed to patients.
William E. Fantegrossi is an associate professor of pharmacology and toxicology at the University of Arkansas for Medical Sciences College of Medicine who has done contract work for the DEA testing new drugs being found on the streets. He spoke with me while researching a story for the Columbia Journalism Review about the myth that fentanyl can endanger law enforcement personnel through skin contact (spoiler: it can’t). He has seen new formulations showing up in street supplies, some with radically different properties than conventional, pharmaceutical fentanyl.
“There are literally hundreds of [fentanyl analogues], most of them we still don’t know anything about,” Fantegrossi said during our interview. He explained that street chemists make changes to the fentanyl formulation so that it can have a variety of effects including making it feel stronger at lower doses, or making the drug “last three times as long.” A lot of attention has been given to the danger these variations pose to users, who don’t necessary know what they’re getting each time they use a new bag. But one factor that has not gotten as much media attention is what role this could play in buprenorphine treatment.
Buprenorphine works by filling opioid receptors similarly to drugs like heroin or fentanyl. But it doesn’t fit them as perfectly. That means it won’t produce the same sense of euphoria or pain relief. Because it has a higher affinity for those receptors, however, it will stop other opioids from taking effect if someone tries to use, for example, heroin after taking buprenorphine. If someone tries to use buprenorphine after taking heroin, however the bupe will knock the heroin out of the receptor. In that scenario, a user with a dependency on heroin or other opioids will go into a state of precipitated withdrawal. Essentially, his body will be suddenly forced to experience the full force of the withdrawal period all at once. It is a grueling and potentially life threatening experience. It’s also the reason why physicians who are starting patients on buprenorphine make sure to wait a specific period of time before administering that full dose. For short acting opioids like heroin or pharmaceutical fentanyl, 12 to 24 hours opioid-free is usually long enough to wait before starting buprenorphine. But what happens when street supplies contain illicit fentanyl formulations with unknown effects, including unknown durations?
When to administer a first dose of buprenorphine is not just decided by the length of time since the patient last used an opioid. Medical staff—or patients taking their first dose at home—should also use the severity of withdrawal as a guideline. This can be somewhat difficult, since every person is different. While some people experience vomiting and diarrhea at the height of their opioid withdrawal, others find their worst symptoms are chills and agitation. So it is important for patients to be honest about what their withdrawals typically look like—and for providers to trust what their patients report.
The Clinical Opioid Withdrawal Scale (COWS) is a checklist of common withdrawal symptoms used to determine the objective severity of a patient’s withdrawal. Objective means of determining patient discomfort—such as pupil dilation, inability to sit still, and excessive sweating—can help providers gauge whether or not it’s safe to start the first dose of buprenorphine, regardless of how much time has elapsed since their last use of an opioid. It is also important for patients to accurately measure and report less visible withdrawal symptoms, like anxiety, cravings, and stomach pains. Even if it’s been 24 hours since a patient’s last drug use, if she doesn’t know her “heroin” was actually (or only) heroin, she could end up experiencing precipitated withdrawal because there was still some longer acting fentanyl in her system. If you’re self-determining when to start your first dose of buprenorphine, it’s really important to make sure you’re scoring as being in mid to high range withdrawal, which is usually a six or higher on the COWS scale. Taking that first dose too early could come with serious consequences—and might even land you in the emergency department.
Buprenorphine is still a highly effective treatment for addiction to illicit fentanyl. But because you and your doctor may not know the exact properties or half-life of the drugs you’ve been taking, it’s very important to pay close attention to your withdrawal symptoms. Waiting for that first dose of buprenorphine is tough, especially when your cravings are calling. But it’s important to make sure you are fully in withdrawal before starting buprenorphine. Whether you’re inducting at home or in a medical setting, make sure you don’t take that first dose just because it feels like enough time should have passed. Waiting is tough, but avoiding precipitated withdrawal is absolutely worth it!