Atypical reactions to heroin in users in five states have been attributed to contamination with the β-2 adrenergic receptor agonist clenbuterol, according to a report from the Centers for Disease Control and Prevention.
The 26 cases reported from January through April in Connecticut, New Jersey, New York, North Carolina, and South Carolina are the “first published accounts of poisoning from clenbuterol associated with reported heroin use” (MMWR 2005;54:793–6).
Clenbuterol is approved for limited veterinary use in the United States but is also used illicitly as an alternative to anabolic steroids in humans and livestock because it can increase muscle mass, the report noted. The cases “likely represent a fraction of actual cases of clenbuterol poisoning,” since patients might not undergo medical evaluation for fear of legal repercussions. Patients also might have presumed–as emergency physicians and hospital intensivists might have–that the effects were related to a known coingestant, the report said.
Heroin typically produces euphoria, miosis, and respiratory and central nervous system depression. The cardiovascular effects associated with these cases are not common.
The six most common signs, symptoms, and laboratory findings among the cases included tachycardia (24 of 26 cases), hypokalemia (22 of 24), palpitations (22 of 26), hyperglycemia (19 of 23), chest pain (15 of 26), and hypotension (14 of 26). Other symptoms reported less often have been nausea, shortness of breath, agitation, and tremor.
Only eight of the cases were confirmed because the assay for clenbuterol is not available in the majority of laboratories; other cases were classified as probable (16) and suspected (2).
Heroin-related clenbuterol toxicity may be diagnosed in the laboratory by detecting clenbuterol in urine, blood, or environmental samples (such as heroin).
The report indicated that it is unknown if the cases represent the adulteration of a single source of heroin before widespread distribution or the adulteration of multiple sources, or if the substance used by each patient was heroin contaminated with clenbuterol or pure clenbuterol sold as heroin. In the mid-1990s, heroin adulterated with scopolamine caused widespread poisoning in four states (MMWR 1996;45:457–60).