Correspondence

Confusion of Nelfinavir and Nevirapine

N Engl J Med 1998; 338:396-397February 5, 1998

Article

To the Editor:

Nevirapine (Viramune), manufactured by Roxane Laboratories, is a non-nucleoside inhibitor of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase. Nelfinavir (Viracept), manufactured by Agouron Pharmaceuticals, inhibits the HIV-1 protease enzyme. Unfortunately, these medications have similar generic and brand names, as well as available tablet strengths (nevirapine, 200 mg; nelfinavir, 250 mg). Therefore, the potential for drug-dispensing errors is substantial.

Within a two-week period, two patients with HIV infection presented to our outpatient HIV clinic because they were concerned about their medication. One patient, who had received a new prescription for nelfinavir (250 mg per tablet; three tablets three times a day with meals), noticed that the medication name on the label did not coincide with the medication name on the dispensed bottle. The pharmacy had inadvertently placed the appropriate nelfinavir label on a bottle of nevirapine. Fortunately, the patient had not taken the incorrectly labeled medication.

The second patient had recently been prescribed stavudine, lamivudine, and nelfinavir. Three days after starting the medication, she had severe fatigue, hypersomnia, and nausea of sudden onset. The medications were stopped, and the patient was seen at the clinic four days later, at which time her symptoms had improved. Her vital signs were as follows: temperature, 37.4°C (99.3°F); blood pressure, 100/69 mm Hg; pulse, 88 per minute; and respiratory rate, 20 per minute. The patient had a diffuse papular rash on her face and neck, which she said had improved after she discontinued the medication. When her medication was examined, it was discovered that three bottles of nevirapine had been erroneously labeled as nelfinavir. For three days the patient had taken nevirapine (three tablets three times a day). The standard dosage of nevirapine is one tablet per day for 14 days, then one tablet twice a day.

Adverse drug events are common, preventable, and costly.1,2 Because of the similarity of these drugs in terms of their names, the dose per tablet, and their clinical indications, physicians and pharmacists should be particularly careful when prescribing, transcribing prescriptions for, and dispensing nevirapine and nelfinavir in order to prevent potentially serious adverse drug reactions or subtherapeutic dosing.

Blake Max, Pharm.D.
Nike Mourikes, M.D.
Cook County Hospital, Chicago, IL 60612

2 References

1. 1

   Bates DW, Cullen DJ, Laird N, et al. Incidence of adverse drug events and potential adverse drug events: implications for prevention. JAMA 1995;274:29-34
   CrossRef | Web of Science | Medline

2. 2

   Johnson JA, Bootman JL. Drug-related morbidity and mortality: a cost-of-illness model. Arch Intern Med 1995;155:1949-1956
   CrossRef | Web of Science | Medline

Author/Editor Response

A spokesperson for Roxane Laboratories replies:

To the Editor: These two incidents are unfortunate examples of medication errors that may be attributable to more than simply the names of the two drugs in question. Regardless of the steps taken to reduce medication errors, dispensing mistakes, such as the erroneous dispensing of Viramune (nevirapine) instead of Viracept (nelfinavir), do occur. However, these two products are distinct, with a variety of notable differences between them, including: differences in the product label, appearance of the tablets, dose strength, and packaging. Roxane Laboratories provides educational items such as “Daily Dosing of Available Antiretroviral Agents” charts that contain photographs of each table or capsule, depending on the drug.

We have been a leader in supporting programs to reduce medication errors. We will continue with these efforts in the hope that we can help pharmacists reduce unfortunate dispensing errors such as those described by Max and Mourikes.

Editor's note: Agouron Pharmaceuticals was offered the opportunity to reply but declined to do so.

Kirk V. Shepard, M.D.
Roxane Laboratories, Columbus, OH 43228-8601

Citing Articles (4)

Citing Articles

1. 1

   Jean-François Brasme, Frédéric Mille, Mounir Benhayoun, Françoise Bavoux, Albert Faye, Natacha Teissier, Eric Lachassinne, Stéphane Dauger. (2008) Uncomplicated outcome after an accidental overdose of nevirapine in a newborn. European Journal of Pediatrics 167:6, 689-690
   CrossRef

2. 2

   Jennifer Cocohoba, Betty J. Dong. (2007) ARV Medication Errors: Experience of a Community-Based HIV Specialty Clinic and Review of the Literature. Hospital Pharmacy 42:8, 720-728
   CrossRef

3. 3

   Jennifer Gray, Rodney W. Hicks, Cristi Hutchings. (2005) Antiretroviral Medication Errors in a National Medication Error Database. AIDS Patient Care and STDs 19:12, 803-812
   CrossRef

4. 4

   &NA;. (1998) Don't confuse nevirapine and nelfinavir. Reactions Weekly &NA;:689, 3
   CrossRef