Contaminant in cocaine impairs immune systems

Toxicologists across the country are sounding the alarm about a contaminant increasingly found in cocaine that is impairing cocaine users' immune systems, subjecting them to various infections and, in some cases, causing death.

“usually reversible after exposure to levamisole is terminated.”

The U.S. Drug Enforcement Agency estimates some 70 percent of cocaine currently coming into the country is contaminated with levamisole - a drug used to de-worm animals. The drug can cause dangerous effects in people, most notably agranulocytosis, or a low white blood cell count, which prevents the immune system from fighting infections.

Dr. Steven Seifert, medical director of the New Mexico Poison and Drug Information Center and a board member for the American Association of Poison Control Centers, co-authored a report on the current status of levamisole-contaminated cocaine that was published in the U.S. Centers for Disease Control and Prevention's Morbidity and Mortality Weekly Report in December 2009. The report reviewed what had been previously known and included additional cases of agranulocytosis linked to people with a history of cocaine use.

It is unclear when levamisole started contaminating cocaine supplies or why, but the contamination appears to be widespread: In July 2009, the Drug Enforcement Agency reported detecting levamisole in nearly 70 percent of seized cocaine lots coming into the United States.

Seifert said the public health threat presented by this contamination is underappreciated and is being under-reported because of a lack of awareness in the medical community. Physicians should suspect levamisole-contaminated cocaine in patients presenting with immune suppression, with or without infection, and should contact their county or state health departments for assistance with testing and epidemiologic investigation. Physicians with questions about the impact of levamisole should call their poison center at 1 (800) 222-1222. Doctors should also warn patients known to use cocaine of the presence of a potentially lethal contaminant in cocaine supplies.

In Arizona, five doctors for the Banner Good Samaritan Poison and Drug Information Center in Phoenix recently authored a "Dear Colleague" letter urging fellow physicians to consider the possibility of levamisole exposure in patients who appear to have impaired immune systems, including testing urine for cocaine. They wrote that the agranulocytosis is "usually reversible after exposure to levamisole is terminated."

Both centers are members of the American Association of Poison Control Centers, which maintains a database, the National Poison Data System (NPDS), that tracks calls to poison centers. According to the association, poison centers have received 25 calls related to weakened immune systems from patients who have used cocaine since Jan. 1, 2009. Of those, two cases resulted in death.

Jim Hirt, executive director of the American Association of Poison Control Centers, said poison centers are uniquely positioned to often be the first to see public health threats. "Poison centers have been on the forefront of public health surveillance," he said. "And this is another example of how medically staffed poison centers can track public health problems in the making."

SOURCE American Association of Poison Control Centers