Can a person get high from Suboxone or buprenorphine, the active part of that medication? I suspect most pharmacists, police officers, and legislators would answer ‘yes!’, but the answer is more complicated. The people who serve patients who take Suboxone should learn how the medication works, when it is dangerous, and when it isn’t.
The actions of all opioids are impacted by tolerance. All mu-receptor opioids including morphine, heroin, and fentanyl are cross-tolerant at the mu opioid receptor. In other words, one opioid will replace another opioid in equipotent doses. If a person is tolerant to 100 mg of oxycodone per day and has only hydrocodone, it takes about 150 mg of hydrocodone/day to avoid withdrawal. Online calculators help with similar dose conversions.
Opioid agonists can be added together, but the total effect is not equal to the sum of each opioid. The most-potent opioid in the mix usually accounts for most of the combination’s opioid effect.
Buprenorphine is a Partial Agonist
Buprenorphine is a partial agonist with blocking and activating effects at the mu receptor. Buprenorphine has a high binding affinity, meaning that it binds very tightly to mu opioid receptors (affinity is the ratio between association constants and dissociation constants). That high affinity allows buprenorphine to displace most other opioids, including fentanyl. Partial agonists with high affinity like buprenorphine , through their balance of activating and blocking receptors, ‘set tolerance’ at a certain level, which coincides with the maximum effect of buprenorphine at opioid receptors. That opioid effect is about the same as the effect of 35 mg of methadone per day. One problem associated with changing patients from methadone to buprenorphine is ‘tolerance mismatch’. That mismatch occurs when a patient is tolerant, for example, to 100 mg of methadone per day and changes to buprenorphine. Buprenorphine immediately ‘pulls’ tolerance lower, causing mild to moderate withdrawal for days to weeks.
Greater precipitated withdrawal occurs if buprenorphine is administered when opioid agonists are bound to the mu receptor. Even in cases of lower opioid tolerance, buprenorphine displaces bound agonist with an antagonist-like effect, causing withdrawal symptoms that can be severe but typically last only 24-48 hours.
What about Naloxone?
The effects described above have nothing to do with naloxone. Naloxone was added to some buprenorphine products to reduce the attractiveness of intravenous misuse of buprenorphine. Naloxone has no effect on sublingual buprenorphine. From discussions with patients, I question whether naloxone has much of an effect even when the combination is dissolved and injected. Studies show that naloxone reduces the ‘liking score’ when buprenorphine is injected, but I question whether that reduction is significant in those who inject Suboxone and other combination products. The main reason I’ve heard for injecting Suboxone is because intravenous use increases bioavailabiliy, making a dose stretch out three-times longer. That extra time is valuable to a person trying to avoid withdrawal.
Who Abuses Buprenorphine?
Any person using heroin or fentanyl regularly likely has an opioid tolerance much greater than the full effect of buprenorphine. For those people buprenorphine at best will cause tolerance mismatch, where severe withdrawal symptoms are relieved without significant euphoria or ‘high’. If those people have heroin or fentanyl in their systems buprenorphine is likely to precipitate severe withdrawal. These phenomena will occur whether buprenorphine is taken sublingually or intravenously.
There are two scenarios where a person may want to abuse buprenorphine. The first is someone who lacks a significant tolerance to opioids. In those cases buprenorphine is likely to cause a significant opioid effect that can be fatal in combination with other respiratory depressants. I have consulted in these rare but horrible cases, which usually involve a young person experimenting with multiple unfamiliar substances. If that same opioid newbie survives and tries buprenorphine the next day, the opioid effect will be muted. After a few days, additional doses of buprenorphine will have almost no effect. The only way for such a person to get ‘high’ again would be to stop buprenorphine, go through a week or two of withdrawal, and take it again, which is not an attractive proposition. The primary risk is if the person seeks out other illicit opioids to avoid withdrawal. I see this as the main problem related to buprenorphine abuse.
The second scenario is in regular opioid users who made the decision, for whatever reason, to avoid illicit opioids. In such cases buprenorphine can prevent the worst withdrawal (when taken correctly) and serve as a bridge to continued drug use or to treatment. Over the years I have had many patients in the latter group; people who started illicit buprenorphine to get away from active addiction, then sought out a prescriber for treatment.
A Hidden Benefit?
There is an ‘accidental treatment’, or at least harm reduction, component to buprenorphine abuse. The ‘high’ sought by opioid addicts requires significant receptor activation, and bound buprenorphine lessens that activation for several days, even longer in some people. If a person takes buprenorphine, one dose will prevent the euphoric effect of illicit opioids for a few days. Bound buprenorphine also reduces the risk of respiratory depression from other opioids. That protection is not absolute, and can be overcome by high doses of opioid agonists. The death-reducing effects of buprenorphine are the reason why many ER docs now distribute several days of the medication to patients who present in withdrawal.
In summary, the primary risk of buprenorphine abuse and diversion is to opioid-naive individuals, either causing overdose or introducing those individuals to illicit opioid agonists. The risk of buprenorphine abuse among people who are already attached to opioids is small, and the likelihood of harm is very low. At least some people chronically attached to opioids use diverted buprenorphine as a bridge, intended or not, to treatment. Others use buprenorphine as a temporary respite from the ravages of agonists.