TreatmentUpdate61; Volume 7, No. 7; July 1995
Sean Hosein

Licensed for the prevention of MAC (Mycobacterium avium complex) infection, rifabutin (Mycobutin) in a dose of 300 mg/day can delay the appearance of symptoms of MAC infection. Should symptoms of MAC infection appear, doctors are likely to treat it with a combination of antibiotics, which in some cases may include rifabutin. As more people become exposed to the drug, it is likely that side effects first seen in small numbers of patients will appear in more people. Over the past 18 months there have been increasing reports of side effects of rifabutin affecting the eye.

* DETAILS

A number of research subjects as well as patients using rifabutin have developed eye inflammation. Symptoms reported include:

+ painful/painless loss of vision + increased sensitivity to light + blurred vision + redness + itching + painful movement of the eyeball

* CAUSES

These changes appeared to be caused by changes in the pressure inside the eyeball. Infection inside the eye could also cause this condition, but in all cases technicians could not detect microbes in the eye. As well, most of the people were using a number of drugs and an interaction among them could cause this complication.

After reviewing different reports it became clear that there were some drugs that were used by all subjects, including;

+ rifabutin (300 to 600 mg/day) + clarithromycin (up to 2 g/day) + ethambutol (up to 15 mg/Eg/day) + fluconazole (200 mg/day or more)

The researchers writing these reports agree that rifabutin appeared to be the cause of the eye inflammation. Fluconazole may increase the concentration of rifabutin in the blood, as might clarithromycin.

* TREATMENT

In nearly all cases stopping the use of rifabutin and/or putting drops of corticosteroids in the eye resulted in recovery ranging between 2 and 12 weeks. The dose of corticosteroids was slowly reduced once recovery began.

In some people use of rifabutin has turned their skin yellow/orange, a condition that is not harmful. Given that rifabutin stains other body fluids yellow/orange, this is not surprising.

REFERENCES:

1. Shfran SD, Deschenes J. Miller M, Phillips P and Toma E. Uveitis and pseudojaundice during a regimen of clarithromycin, rifabutin and ethambutol. New England Journal of Medicine 1994;330(6):438-439.

2. Jacobs DS, Pileiro P. Kuperwaser MG, et al. Acute uveitis associated with rifabutin use in patients with human immunodeficiency virus infection. American Journal of Oph- thalmology 1994;118(6):716-722.

3. Saron BR, Maguire AM, Nichols C, et al. Hypopyon uveitis in patients with Acquired Immunodeficiency Syndrome treated for systemic Mycobacterium avium complex infection with Rifabutin. Archives of Ophthalmology 1994;112:1158-1165.

4. Havlir D, Torriani F and Dube M. Uveitis associated with rifabutin prophylaxis. Annals of Internal Medicine 1994;121(7):510-512.

950701
CATE6111

Copyright © 1995 - TreatmentUpdate. Reproduced with permission. Reproduction of this article (other than one copy for personal reference) must be cleared through the Editor, The Canadian AIDS Treatment Information Exchange, 555 Richmond St. West, Suite 505, Box 1104, Toronto, ON, M5V 3B1 • Phone: 416-203-7122 • Toll Free: 1-800-263-1638 • Fax: 416-203-8284  http://www.catie.ca