A daily low dose of cotrimoxazole for preventing opportunistic infections in adults with HIV

Cotrimoxazole helps to prevent infections in adults who are HIV-infected but may increase resistance to the drug and more trials are needed.

Human immunodeficiency virus (HIV) attacks the immune system, leaving people vulnerable to infections. Such infections often cause death or serious complications. Anti-viral drugs can slow HIV. However, most HIV-infected people live in developing countries without access to these treatments. Preventing infections is therefore the main aim of HIV treatment in developing countries. A daily low dose of cotrimoxazole , an antibiotic (a drug that fights bacterial infections), is used to try to prevent infections and improve survival, but with unknown effectiveness for HIV-infected people. The review found cotrimoxazole improved survival in some areas of Africa and found improvements in other outcomes, but adverse effects and possible drug resistance are unclear. More trials are needed.

Authors' conclusions: 

In the trials included in the review, cotrimoxazole prophylaxis had a beneficial effect in preventing death and illness episodes in adults with both early and advanced HIV disease. However, the wider applicability of these findings is unclear, in particular to areas with higher background bacterial resistance to cotrimoxazole. Further trials would be required in differing settings to widen applicability.

Read the full abstract...

The prevention and early treatment of infections are the mainstay of the medical management of the majority of people with HIV infection, who live in low income countries without access to antiretroviral drugs. Cotrimoxazole is cheap and effective against a wide range of organisms. However, routine prophylactic treatment is difficult to deliver in low-resource settings, and could also lead to increased resistance to the drug.


To assess the effects of routinely administered cotrimoxazole on death and illness episodes in HIV infected adults.

Search strategy: 

We searched the Cochrane HIV/AIDS Group register, the Cochrane Controlled Trials Register, MEDLINE, LILACS, AIDSLINE, AIDSTRIALS and AIDSDRUGS databases, and proceedings and abstracts from AIDS and tuberculosis (TB) conferences (search date July 2001). We checked reference lists for trials and other pertinent articles, and contacted pharmaceutical companies and experts in the field.

Selection criteria: 

Randomised or quasi randomised trials comparing routinely administered cotrimoxazole versus placebo or no treatment in adults (age greater than 13 years).

Data collection and analysis: 

Two reviewers independently assessed trial eligibility and quality, and extracted data. Where data were incomplete or unclear trial authors were contacted for further details.

Main results: 

Four trials involving 1476 people were identified. Three trials (1416 people) studied heterosexual men and women in West Africa. A fourth trial was of homosexual men on chemotherapy for Kaposi's sarcoma, in the United States. Meta-analysis of the three African trials showed a significant beneficial effect of cotrimoxazole for death: relative risk 0.69 (95% confidence interval 0.55 to 0.87); for morbid events: 0.76 (0.64 to 0.9); and for hospitalisation: 0.66 (0.48 to 0.92). There was no significantly greater risk of adverse effects: relative risk 1.28 (0.47 to 3.51). Effects were similar in people with early and advanced HIV disease. Insufficient evidence was found on effects in areas with higher bacterial resistance or in people on antiretroviral therapy.