108 Warning: Generic Suboxone Not Equal to Name Brand

Abstract:

Introduction:

On June 14, 2018, the FDA approved generic buprenorphine/naloxone, as an alternative to the brand Suboxone (FDA,2018). A patient who developed acute withdrawal symptoms when switched from Suboxone to generic buprenorphine/naloxone at the same dosage, with resolution with replacement with brand name Suboxone, is presented. Induction of withdrawal with generic buprenorphine/naloxone has not heretofore been described.

Methods:

Case Study: A 39-year-old right handed single male presented with a past medical history of intravenous heroin dependence. He was relapse free for 5 years and without change on Suboxone film 8mg/2mg twice daily, and was provided with prescriptions for the same, which was substituted to generic brand Dr. Reddy’s Lab SA buprenorphine HCl/naloxone HCl 8mg/2mg film. After two days on this, one hour after taking generic buprenorphine/naloxone film, symptoms of withdrawal began as manifest by hot flashes, diaphoresis, cold chills, leg cramping, and nausea without vomiting. These were the same symptoms he experienced during his past inpatient withdrawal from opioids. These symptoms recurred every day for an entire week until switching back to brand name Suboxone, whereupon his withdrawal symptoms resolved.

Discussion:

The mechanism whereby the generic buprenorphine/naloxone combination induced withdrawal symptoms is unclear. It appears that this generic version was either not effectively blocking the mu receptors or the naloxone was inducing a withdrawal state. Possibly the porous nature of the film was such that less of the buprenorphine was absorbed through the mucosa. As a result, less was transferred into the bloodstream, across the blood brain barrier, to the nucleus accumbens, and ultimately on kappa opioid/mu receptor (Centerwatch, 2002). Alternatively, a greater amount of naloxone may have been absorbed transmucosally, thus inducing withdrawal. The absorption may have been normal, but the exact milligram dosage may not be accurate with either too little buprenorphine or too much naloxone. On the other hand, this buprenorphine compound may have been pH sensitive, such that it became inactivated upon exposure to the mildly acidic salivary pH. He could have been malingering this response. Again this is unlikely since he was not given a higher dose of buprenorphine/naloxone, rather the same dose of Suboxone as previously prescribed. It is important that physicians be aware of the possibility for acute withdrawal and increased cravings, which can lead to relapse while using this agent. Further investigation of the efficacy of the generic variant and Suboxone as replacement therapy is warranted.