Buprenorphine (Subutex), a semi-synthetic opiate alkaloid derivative with partial μ-opioid receptor agonist and κ-opioid receptor antagonist activity, is used for treatment of opioid dependence or as a long-acting analgesic (1). It is available in several forms including sublingual tablets and has a mean plasma elimination half-life of 37 hours (2). Like other opioids, it can cause hypersensitivity reactions by directly activating mast cells or basophils in an IgE-independent manner (3). Reactions to buprenorphine have been reported in clinical trials and post-marketing experience: the most common reactions include rashes, hives, and pruritus. Less common reactions include bronchospasm, angioedema, and anaphylactic shock (2). Such systemic reactions to buprenorphine, however, are rare (4,5). We now report on a 21-year-old woman with a six-year history of opioid dependence, who had hypersensitivity reactions to many opioid medications, including buprenorphine, heroin, oxycodone, hydrocodone, and methadone, and who was successfully desensitized to buprenorphine.In our patient, heroin caused severe hives, vomiting, coughing, and sensation of throat closing; oxycodone resulted in hives and vomiting; hydrocodone and methadone resulted in severe nausea and vomiting. After multiple unsuccessful attempts to quit using drugs on her own, she entered a substance abuse treatment program and achieved remission for eight months, treated with sublingual buprenorphine twice daily along with cetirizine daily to minimize adverse reactions. She initially tolerated buprenorphine with cetirizine without reactions, but six months into her treatment, after missing a dose of cetirizine, she developed hives, dizziness, and a sensation of throat closing. Although these symptoms improved with cetirizine, further buprenorphine doses were accompanied by skin tingling, flushing, hives, and sometimes also with facial edema, nausea, or respiratory symptoms (sensation of throat closing associated with coughing and difficulty breathing). Over the next two months, respiratory symptoms became more frequent and severe. Symptoms occurred several times per week, typically lasting 10
NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript minutes, and improving with cetirizine. Because of these reactions, buprenorphine was discontinued and these symptoms abated. However, she then relapsed into heroin use, which caused severe reactions with hives, vomiting, diarrhea, and a sensation of throat closing, despite remaining on daily cetirizine. She was referred for further evaluation of buprenorphine allergy.Physical examination was notable for mild dermatographia. Laboratory evaluation was notable for baseline total tryptase that was initially mildly elevated at 18 ng/mL (reference range, 1-15 ng/mL); repeat 13 ng/mL. CBC showed 5% eosinophils, but was otherwise normal, as were LFTs and TSH. Because she required a minimum of several months of sublingual buprenorphine to treat her substance dependence, desensitization to buprenorphine was...