Illicit drug users who present with suspected infectious illnesses and/or active skin lesions may actually have been exposed to levamisole, an agent used by veterinarians to deworm animals that is frequently used to adulterate cocaine and heroin, new research suggests.

A case series study showed that 23 individuals who presented at healthcare facilities with unexplained neutropenia or skin necrosis reported using cocaine or heroin in the past month. In addition, nearly one half of these patients were admitted to the hospital from emergency departments (EDs), 3 individuals were admitted to the intensive care unit, and 1 died.

Of the 23 cases, 12 were from Michigan, 10 from New Mexico, and 1 from Minnesota.

"Not only is the cocaine causing harm, but the levamisole in it is causing health problems serious enough to bring people to the emergency room," said lead author Sara J. Vagi, PhD, from the Centers for Disease Control and Prevention in Atlanta, Georgia, in a release.

The investigators note that because cocaine is estimated to be used by 2 million Americans and because individuals report being generally unaware of these potentially life-threatening effects, this is "an important emerging health concern."

"Education about the dangerous health effects from exposure to levamisole-contaminated drugs should be incorporated in anti–drug abuse public health messaging," they write.

The study was published online January 29 in Annals of Emergency Medicine.

According to the researchers, 69% or more of cocaine and 3% of heroin seized by the US Drug Enforcement Administration (DEA) as of 2009 contained levamisole.

This agent had been used up to 1999 for rheumatoid arthritis, as an anthelmintic pharmaceutical drug, and as an adjunct to chemotherapy. However, in 2000, use in Americans was restricted after an association was found between the drug and agranulocytosis.

"Today, the only Food and Drug Administration–approved use of levamisole is in livestock as an antiparasitic agent," report the investigators.

They add that it is still used in humans outside this country. But they do not know why it is often added to cocaine.

"Proposed theories include to increase bulk, to enhance stimulatory effects; and to monitor supply, distribution, and sources of origin by the manufacturers," write the study authors.

In September 2009, the US Substance Abuse and Mental Health Services Administration issued a warning about cases of unexplained agranulocytosis in cocaine users.

The following month, the CDC "initiated multistate surveillance for these cases," as well as for cases of neutropenia.

They examined records from state health departments between October 2009 and May 2010 for 46 potential cases. Of these, 23 (52% men; mean age, 44.4 years) met eligibility criteria.

The most common chief complaint from the patients upon presentation involved symptoms of infectious illnesses, which included fever, body aches, and sore throats (n = 12).

In addition, 10 patients reported active skin lesions, with one half reporting the lesions as ulcerative or necrotic. A total of 83% of all the patients presented to EDs.

Most of the participants (n = 19) reported taking only cocaine during the past month. Only 1 reported using only heroin.

Nine of the 10 patients who participated in formal interviews reported using cocaine more than 2 or 3 times per week. In addition, 6 of the patients reported using cocaine for a period longer than 2 years, and 6 reported a preference for crack cocaine.

"All were unaware of exposure to levamisole through cocaine and of levamisole's inherent toxicity," write the investigators.

Dr. Vagi noted that the serious health effects associated with levamisole, the substantial associated healthcare costs, and the large number of cocaine users in the United States "put emergency physicians on the front line of this public health problem."

In addition, because of the DEA's reports showing that more than two thirds of the cocaine they seized before its arrival in the United States is laced with levamisole, she said that "our sample size is likely an underestimation."

The study authors have reported no relevant financial relationships.

Ann Emerg Med. Published online January 29, 2013. Full article

Medscape Medical News © 2013  WebMD, LLC

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Cite this: Cocaine, Heroin Cut With Animal Dewormer Send Users to ED - Medscape - Jan 30, 2013.

is a freelance writer for Medscape.

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