Furazolidone

WHAT WAS BEHIND THIS PATIENTS RACING THOUGHTS AND EUPHORIA?

A 36-YEAR-OLD MAN WITH AIDS CAME TO THE ED WITH acute, severe diarrhea and fever, according to a report in the April 1998 issue of Clinical Infectious Diseases. His stool was positive for Giardia lamblia, and he received two courses of metronidazole (for 5 and 14 days) and a 5-day course of furazolidone (Furoxone). After each course of therapy, he had short-term improvement but then relapsed, so his health care provider ordered a 30-day course of furazolidone, 100 mg q.i.d.

Furazolidone causes monoamine oxidase (MAO) inhibition, so the patient was advised of potential interactions with foods containing tyramine and sympathomimetic drugs. He also was prescribed megestrol, dapsone, and oxycodone with acetaminophen (Percocet). After a week, his diarrhea improved, and by the end of the second week, he noted increased energy and appetite-and uncharacteristic frenetic activity.

After 4 weeks of therapy, the patient reported to his psychiatrist that he was also experiencing severe insomnia, racing thoughts, and feelings of euphoria. These and other symptoms were diagnosed as a hypomanic episode. After furazolidone therapy was discontinued, the symptoms subsided.

What went wrong?

Monoamine oxidase inhibition by furazolidone peaks between days 10 and 20 of therapy. Typically, furazolidone is used only for 7 to 10 days, but this patient had 30 days of therapy.

What precautions can you take?

Exercise caution with long-term use of furazolidone. If long-term use is indicated, teach the patient to avoid tyramine-containing foods such as broad beans, yeast extracts, strong unpasteurized cheeses, beer, wine, pickled herring, chicken livers, and fermented products. Tell him not to use over-the-counter decongestants. Review his medications with him and reduce dosages of other MAO-inhibiting drugs, sedatives, antihistamines, tranquilizers, and opioids.

Source: "Furazolidone-Induced Mood Disorder during the Treatment of Refractory Giardiasis in a Patient with AIDS," Clinical Infectious Diseases, A. Elliott, et al., April 1998.

Dr. Shuster is clinical associate professor, Temple University, and clinical pharmacist, Medical College of Pennsylvania Hospital, both in Philadelphia, Pa. Send examples of adverse drug reactions to: Joel Shuster, PharmD, The Institute for Safe Medication Practices, 300 W. Street Rd., Warminster, PA 18974. Fax: (215) 956-9266. If we publish your item (anonymously), we'll pay you $25.

Copyright Springhouse Corporation Apr 1999
Provided by ProQuest Information and Learning Company. All rights Reserved