Practitioners' Reporting News

Lamictal - Similar Name Error Alert

Issued February 6, 2001

Numerous medication error reports received by the USP Medication Errors Reporting (MER) Program involve problems that arise from similar drug names. A number of reports have focused on the products, Lamictal® (lamotrigine), an antiepileptic drug, and Lamisil® (terbinafine hydrochloride), an antifungal drug. Of eleven reports received, three reported that these sound-alike and look-alike brand names had the potential to cause an error, while the remaining eight described errors that actually transpired. Of the eight actual errors, seven resulted in patients taking the wrong medication. One patient received over 30 doses of Lamictal 25 mg instead of Lamisil 250 mg. Glaxo Wellcome, the manufacturer of Lamictal, has issued a "Dispensing Errors Alert" calling on prescribers, dispensers, manufacturers, and patients to be aware of the potential for error in order to help avoid future errors. This is especially important because patients with epilepsy who do not receive their antiepileptic medication could be at risk for developing serious consequences, including status epilepticus.

Lamictal has also been confused with other products that have similar proprietary names. The USP MER Program has received six reports citing errors between Lamictal and the antidiarrheal product, Lomotil® (diphenoxylate hydrochloride and atropine sulfate). One report described an error where a prescription for Lomotil 2.5 mg was interpreted as Lamictal 25 mg because the handwriting was unclear and the decimal point was missing between the "2" and the "5." The pharmacist, who knew the patient had epilepsy and took an antiepileptic medication, learned through counseling the patient that the medication had in fact been prescribed to treat diarrhea. In three additional MER Program reports involving Lamictal and Lomotil, it was noted that patient counseling was instrumental in preventing the patients from receiving the wrong medication.

In addition to confusion between the brand name products, Lamictal's generic name, lamotrigine, has been the source of four medication error reports to USP. Each report describes a circumstance where the patient received lamotrigine 150 mg instead of the intended drug, lamivudine, Glaxo Wellcome's antiviral, Epivir® 150 mg, because of the similar sounding generic names.

The National Coordinating Council for Medication Error Reporting and Prevention (NCC MERP) has adopted a set of recommendations aimed at establishing and reinforcing safe dispensing techniques. These recommendations can be accessed at the NCC MERP Web site, www.nccmerp.org. One of the NCC MERP recommendations on patient counseling was instrumental in preventing four of these dispensing errors. Other measures that may help to prevent errors involving similar sounding drug names include: spelling back the name of the drug when a phone-in prescription is received, providing the indication for use when appropriate, questioning new prescriptions if the drug does not seem to be appropriate for the patient's condition when the patient profile is current, and flagging similar sounding product names in computer entry and pharmacy computer systems.

Patients can take an active part in reducing the chances of medications errors by knowing the name of the medication they have been prescribed and the reason it was prescribed. When obtaining a refill the patient should question any changes in color, shape, size, and dosage from the original prescription. For additional tips for consumers on medication safety see the USP press release, Ten Ways Consumers Can Help Ensure That Medication Errors Are Avoided  (122KB)


Readers are advised that official USP cautions and warnings for drugs appear in the USP–NF or USP DI. Unless otherwise indicated, any advice or opinions expressed herein reflect solely the judgment of USP staff. Such statements are intended for further consideration and evaluation and may or may not be applicable to a particular practice. The USP Medication Errors Reporting Program is presented in cooperation with the Institute for Safe Medication Practices.