The Institute for Safe Medication Practices has received a number of reports involving brand name medications that may contain different active ingredients in another country.

In one report, a patient was prescribed Dilacor XR (diltiazem extended-release) 120 mg daily for hypertension. While traveling to Serbia, he ran out of medication. A Serbian pharmacist filled the prescription, but he actually dispensed digoxin 0.25 mg because, in Serbia, Dilacor is a brand name for digoxin. The patient did not notice the change in tablet strength, so he continued to take the medication for 3 days upon return to the United States. He took extra doses each day (2-3 tablets), however, because he felt that his blood pressure medication was not working. By the third day, the patient experienced signs of digoxin toxicity, including nausea, vomiting, headaches, and chest pain worsened by exertion. He went to an emergency department and was admitted for monitoring and treatment with Digibind (digoxin immune FAB).

In another case, a hospitalized patient developed gastrointestinal (GI) bleeding, and the medical team was trying to determine the cause. A pharmacy student on the team was asked to find out what “Cartia” was, since the patient had apparently been taking that medication prior to admission. The student found that several Web sites, as well as Micromedex, described Cartia as a 100-mg, enteric-coated tablet of aspirin. When the student reported this information to the team, a decision was made to discontinue the drug, as aspirin can cause GI bleeding. Fortunately, a medication error was averted when it was discovered that the patient was actually taking Cartia XT (diltiazem in the United States), which is bioequivalent to Cardizem CD, to treat hypertension and angina.

Cartia is a trademark for enteric-coated aspirin in New Zealand and Australia. This product can be purchased over the Internet in the United States, however, and both products could be considered heart medications, increasing the risk of error. If a patient taking Cartia XT searches the Web and finds that “Cartia” is available without a prescription and inexpensive (one site advertised 28 tablets for $1.94 in US dollars), a medication error could occur. Confusion also could exist among physicians trained outside the United States or patients who travel between the United States and New Zealand or Australia.

Finally, the trademark Entex LA is used for 2 different products in the United States and Canada. In the United States, Andrx Pharmaceuticals markets a capsule formulation of Entex LA that contains phenylephrine hydrochloride (30 mg extended-release) and guaifenesin (400 mg immediate-release). In Canada, Purdue Pharma Canada supplies Entex LA as a tablet that contains pseudoephedrine (120 mg) and guaifenesin (600 mg). Compounding the confusion, the indicated adult dose for each product is one tablet every 12 hours.

Safe Practice Recommendations

Be cautious of drug information obtained only from the Internet. The Internet knows no national boundaries, so information—even drug names—found may be inaccurate and/or not applicable to health care in the United States. Always question patients on the reason they are taking their medications so as not to rely solely on drug references. Remind patients when they travel to carry an adequate supply of medications and a list by generic and brand name. Those needing a temporary supply while overseas should confirm that the correct drug has been dispensed, as brand name products may contain different active ingredients in different countries.

For a list of drug names in which identical or nearly identical names used in other countries reflect different ingredients, please visit the FDA Web site at: www.fda.gov/oc/opacom/reports/confusingnames.html.