Bactrim/Septra is the most common drug used to prevent and treat PCP (Pneumocystis carinii pneumonia). However, recent reports suggest that a small but increasing number of cases of PCP have appeared in people with HIV despite the use of Bactrim/Septra. One alternative, albeit a more expensive one, to Bactrim/Septra is Mepron (atovaquone). Unfortunately, however, there is now evidence to suggest that the organism that causes PCP may also develop resistance to Mepron.
Doctors in the USA and England have in reported 4 cases of PCP in HIV-positive patients taking Mepron. In at least 2 of the patients, resistance to Mepron was confirmed by genetic testing. All of the subjects had been using Mepron for between 2 and 15 months to prevent PCP at the time the drug failed.
Since PCP-causing microbes appear to need a single key mutation in order to develop resistance to Mepron, the research team suggests that another drug be used with it to avoid this problem. In the case of malaria, Mepron is in fact used successfully in combination with another drug to delay the appearance of resistance.
19990222
CATE9505
Copyright © 1999 - 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
Disclaimer: The editors have taken all such care as they consider reasonable in preparing this database, but they cannot be held responsible for any inaccuracies or mis-statements of fact contained herein. Inclusion in this database of any information on any treatment, therapy, or clinical trial in no way represents an endorsement of that treatment, therapy, or trial by ÆGiS or any of its sponsors. This data should always be used in conjunction with professional medical advice.