Correction to This Article
A May 1 Health item on a study of niacin overdoses incorrectly referred to physician and study author Manoj K. Mittal as a woman.
High-Risk Behavior

Niacin Overdose

Tuesday, May 1, 2007

Although it is touted on the Internet as a way to beat a drug test, taking large doses of the over-the-counter supplement niacin, also known as vitamin B3, is both ineffective and potentially dangerous, researchers at the University of Pennsylvania warn.

Emergency physician Manoj K. Mittal of Children's Hospital of Philadelphia and her colleagues reported earlier this month in the Annals of Emergency Medicine that they had treated four patients for niacin overdose during the past two years. All had taken large quantities of the vitamin after using marijuana or cocaine, and all recovered from the overdose of niacin.

Two patients, both in their early 20s, said they used the vitamin to conceal drug use before undergoing pre-employment urine tests to detect illegal drug use. A third patient, a 14-year-old boy, said he took niacin the day before he was to meet with his parole officer; the fourth, a 17-year-old girl who was found unconscious, said she popped niacin after using ecstasy and marijuana.

Niacin is one of several over-the-counter supplements popularly believed to subvert the results of drug testing. The authors note that a Google search for niacin plus the phrase "pass urine drug test" yielded more than 85,000 results.

It is erroneously believed, the authors write, that massive doses of vitamin B3 can rapidly flush drugs from a user's body and produce a negative drug test for marijuana and cocaine by speeding up metabolism.

In reality, they write, it can prove toxic, causing heart palpitations, vomiting, blood sugar abnormalities and liver failure. The recommended daily dose of niacin is about 14 to 16 milligrams per day; the 14-year-old who was treated at Children's said he took 5,500 milligrams.

An ER physician who does not suspect niacin overdose might conclude the patient was having a severe allergic reaction and might treat the patient with possibly harmful drugs, the authors warn.

A companion editorial by toxicologists at the Rocky Mountain Poison and Drug Center in Denver reported the center had fielded 16 calls between January and September 2006 from people who said they had taken niacin to achieve a negative urine test. About half received medical treatment for overdose, and all recovered, they reported.

"Emergency physicians should consider attempts to mask urine drug screens as a cause of unusual presentation in high-risk populations, such as military, patients on probation and with a history of drug abuse," they wrote.

-- Sandra G. Boodman

© 2007 The Washington Post Company