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Use of Niacin in Attempts to Defeat Urine Drug Testing --- Five States, January--September 2006

In addition to its use as a nutritional supplement, niacin (nicotinic acid or vitamin B3) is medically prescribed to treat hyperlipidemia and hypercholesterolemia. Use of niacin in low doses usually leads to few adverse drug reactions (ADRs); however, at larger doses, niacin can cause skin flushing, itching, and occasionally more serious effects (1). The 2005 annual report of the American Association of Poison Control Centers documented 3,109 reports of exposures to niacin (2). During 2006, the Rocky Mountain Poison and Drug Center (RMPDC) in Denver, Colorado, received multiple calls regarding ADRs after nonmedical use of niacin. A review of call records indicated various uses of niacin, including attempts to alter or mask results of urine drug tests, although no scientific evidence exists that ingestion of niacin can alter a drug test result. To determine the extent of niacin use in attempts to alter drug test results, reports to RMPDC of niacin ADRs were reviewed for the period January--September 2006. The results identified 18 persons who reported nonsuicidal, intentional, nonmedical reasons for using niacin, including eight who specified altering drug test results as their reason for using niacin. Ten other persons, among an additional 18 who offered no reason for niacin use, were categorized as possible users of niacin to try to alter drug test results because of their ages or the amount of niacin ingested. Clinicians, especially those whose patients include teens and young adults, should be aware of the potential use of niacin in attempts to defeat urine drug tests.

RMPDC serves Colorado, Hawaii, Idaho, Montana, and southern Nevada, a total population of approximately 10 million. RMPDC staff members searched their database for telephone calls reporting niacin exposures during January--September 2006. Calls regarding niacin exposures were divided into six categories: 1) unintentional dosing errors in therapeutic users, 2) ADRs after therapeutic use, 3) pediatric unintentional exposures, 4) suicide attempts, 5) ADRs with no reason given for niacin use, and 6) ADRs after nonsuicidal, intentional, nonmedical use. Data collected included the person's age, sex, circumstances of exposure, symptoms, and outcome. Persons who gave no reason for niacin use but were aged <30 years or who reported taking at least 1,000 mg or "large amounts" of niacin in one ingestion were cateogorized as possible users of niacin to defeat urine drug testing. The study was approved by RMPDC's institutional review board and granted a waiver of consent.

A total of 92 calls (72 from persons at home and 20 from health-care providers) reported exposures to niacin. Thirty calls (33%) reported dosing errors or ADRs after therapeutic use, 23 (25%) referred to unintentional pediatric exposures, and 18 (20%) reported ADRs after nonsuicidal, intentional, nonmedical use. An additional 18 calls (20%) reported niacin ADRs with no reason stated for the exposure. Three calls (3%) described attempted suicides.

Among the 18 persons who said their ADRs resulted from nonsuicidal, intentional, nonmedical use of niacin, the median age, excluding three adults of unknown ages, was 18 years (range: 15--50 years). Eight of the 18 persons said they took niacin (1,000 mg--8,000 mg) to alter or mask a drug screening; eight others said they took niacin (400 mg--5,000 mg) to "purify, cleanse, or flush" their bodies; and two said they used niacin as a diet pill. Among the 18 persons who gave no reason for niacin use, eight were aged <30 years, and two patients of unknown age reported taking a 2,000-mg dose and "large amounts" of niacin, respectively; under the case definition, those 10 persons were categorized as possible users of niacin to defeat urine drug testing.

Calls regarding the 18 persons who either said their ADRs resulted from attempts to alter drug test results or who were categorized as possible users of niacin for that purpose came from all five states covered by RMPDC. Twelve calls came from Colorado, two from Idaho, and one each from Hawaii, Montana, and southern Nevada; one call came from California via a manufacturer's hotline telephone number. Among the 28 who either gave a nonmedical reason for niacin use (18 persons) or who stated no reason but were categorized as possible users of niacin to alter drug test results (10 persons), the most common ADRs reported were tachycardia, flushed skin, rash, nausea, and vomiting. Thirteen of the 28 were treated at or referred to a health-care facility. No deaths were reported.

Reported by: C Mendoza, MD, K Heard, MD, Rocky Mountain Poison and Drug Center, Denver Health Medical Center, Colorado.

Editorial Note:

Niacin is well established as a medical treatment for hyperlipidemia (3) and available by prescription in 50-mg to 500-mg tablets or capsules. The initial recommended therapeutic daily dose is 100 mg, three times a day, titrated to a maximum daily dose of 1,000 mg (4). Extended-release niacin tablets and capsules (at 125 mg--1,000 mg) also are available by prescription, usually in a dose of 500 mg at bedtime, to a maximum of 2,000 mg per day. The therapeutic use of niacin often is limited by dermatologic and gastrointestinal ADRs (e.g., tachycardia, flushing, rash, nausea, vomiting, or abdominal pain). These effects usually are self-limited and are more common with dosages >1,000 mg per day, but can occur at any dose. Hepatotoxicity is a rare but serious adverse effect, usually associated with chronic use (5).

No scientific evidence indicates that taking niacin can alter a urine drug test result. However, readily accessible information on the Internet lists ingestion of niacin as a way to prevent detection of tetrahydracannabinol (THC), the main psychoactive ingredient of marijuana. An Internet search on the words "niacin" and "marijuana" can produce tens of thousands of results.

In addition to sales as a prescription drug, niacin is sold over the counter (in 100-mg to 500-mg tablets) and generally is regarded as a safe nutritional supplement with well-known dermatologic and gastrointestinal ADRs that usually are self-limited and resolve with supportive care (1). Death from acute overdose has not been reported, and a minimum lethal dose has not been established (6). However, severe effects in some patients have been reported. A report in press on use of niacin to defeat urine drug tests describes four cases of niacin toxicity that included hepatotoxicity, metabolic acidosis, variations in blood glucose, neutropenia, and electrocardiographic effects (7). Two of the four patients had life-threatening ADRs; one had taken 5,500 mg of niacin during a 36-hour period, and the other had taken 2,500 mg during a 48-hour period.

The findings in this report are subject to at least four limitations. First, the data were collected retrospectively from the RMPDC database; although a specific data set was gathered for each case, persons might have misrepresented the circumstances of their niacin use, leading to misclassification, underreporting of dosages, or inaccurate reporting of symptoms. Second, persons who did not cite a reason for using niacin and were aged <30 years and persons who took more than 1,000 mg or "large amounts" of niacin were categorized as possible users of niacin to alter drug test results; however, those persons might have used niacin for other reasons, including treatment of hyperlipidemia. Third, poison center data might not be representative of all niacin exposures; patients with less severe or no symptoms from niacin use would not contact a poison center. Finally, RMPDC is a regional poison center, and the use of niacin to attempt to alter or mask drug test results might be a regional phenomenon. Further research of national poison center data can provide additional information regarding nonmedical use of niacin.

Public health measures such as school-based education and authoritative Internet communications might help prevent ADRs if directed at those who are prompted to misuse niacin by claims that are not substantiated scientifically. This report underscores the importance of taking medications in appropriate doses and for approved indications as directed by a health-care provider. With the Internet now a common source of medical information, clinicians can expect to encounter patients with unusual ADRs resulting from nonscientific drug use (8) and should familiarize themselves with these effects and counsel their patients accordingly.


  1. CDC. Niacin intoxication from pumpernickel bagels---New York. MMWR 1983;32:305.
  2. Lai MW, Klein-Schwartz W, Rodgers GC, et al. 2005 annual report of the American Association of Poison Control Centers' national poisoning and exposure database. Clin Toxicol 2006;44:803--932.
  3. Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults. Executive summary of the third report of The National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III). JAMA 2001;285:2486--97.
  4. Poisondex® system. Greenwood Village, CO: Thomson Micromedex.
  5. Temple BR. Vitamins. In: Dart RC, Caravati EM, McGuigan M, et al, eds. Medical toxicology. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins, 2004:1022--3.
  6. Bloomquist SE, Dart RC. Cardiovascular drugs. In: Dart RC, Caravati EM, McGuigan M, et al, eds. Medical toxicology. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins, 2004:645--7.
  7. Mittal MK, Florin T, Perrone J, Delgado JH, Osterhoudt KC. Toxicity from the use of niacin to beat urine drug screening. Ann Emerg Med. In press. 2007.
  8. Cone EJ. Ephemeral profiles of prescription drug and formulation tampering: evolving pseudoscience on the Internet. Drug Alc Depend 2006;83S:S31--9.

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Date last reviewed: 4/18/2007


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