From the Guidelines
The recommended prophylactic dose of cotrimoxazole for preventing PCP in HIV patients is one double-strength tablet daily, as stated in the guidelines for preventing opportunistic infections among HIV-infected persons 1. This dose is preferred due to its effectiveness in preventing PCP, as well as its cross-protection against toxoplasmosis and selected common respiratory bacterial infections. Some key points to consider when prescribing cotrimoxazole for PCP prophylaxis include:
- The medication should be initiated when CD4 counts fall below 200 cells/µL or if the patient has a history of oropharyngeal candidiasis or other AIDS-defining illness, as recommended by the guidelines 1.
- Alternative dosing options, such as one single-strength tablet daily or one double-strength tablet three times weekly, may be considered for patients who cannot tolerate the preferred regimen, as noted in the guidelines 1.
- Patients should be monitored for side effects, which can include rash, gastrointestinal disturbances, and rarely, bone marrow suppression.
- For patients who cannot tolerate cotrimoxazole, alternative prophylactic medications, such as dapsone, atovaquone, or aerosolized pentamidine, may be recommended, as stated in the guidelines 1.
From the FDA Drug Label
For the prophylaxis of Pneumocystis carinii pneumonia, the recommended dosage for adults is 1 sulfamethoxazole and trimethoprim tablet (double strength) daily. For children, the recommended dose is 750 mg/m2/day sulfamethoxazole with 150 mg/m2/day trimethoprim given orally in equally divided doses twice a day, on 3 consecutive days per week.
The prophylactic dose of cotrimoxazole for preventing PCP in HIV patients is:
- Adults: 1 double-strength tablet (containing 800 mg sulfamethoxazole and 160 mg trimethoprim) daily.
- Children: 750 mg/m2/day sulfamethoxazole with 150 mg/m2/day trimethoprim given orally in equally divided doses twice a day, on 3 consecutive days per week, with a total daily dose not exceeding 1600 mg sulfamethoxazole and 320 mg trimethoprim 2.
From the Research
Prophylactic Cotrimoxazole Dose for Preventing PCP in HIV Patients
- The recommended prophylactic dose of cotrimoxazole for preventing Pneumocystis carinii pneumonia (PCP) in HIV patients is 160 mg trimethoprim and 800 mg sulfamethoxazole, given three times a week, on Mondays, Wednesdays, and Fridays 3, 4.
- This dose has been shown to be effective in preventing PCP, with a study demonstrating that it completely prevents AIDS-associated PCP in patients with a previous episode of PCP or with a CD4 cell count less than 200 cells/μL 3.
- Another study compared the efficacy of thrice-weekly cotrimoxazole with weekly dapsone-pyrimethamine for the primary prevention of PCP and found that cotrimoxazole was better than dapsone-pyrimethamine in preventing PCP 4.
- The use of cotrimoxazole for PCP prophylaxis has also been shown to provide protection against other opportunistic infections, including toxoplasmosis, salmonellosis, and invasive staphylococcal infections 5.
- In patients with a history of hypersensitivity to cotrimoxazole, desensitization protocols have been shown to be effective in allowing the continued use of cotrimoxazole for PCP prophylaxis 6.
- A randomized trial comparing cotrimoxazole, aerosolized pentamidine, and dapsone plus pyrimethamine for primary prophylaxis of PCP found that cotrimoxazole was effective in preventing PCP, but had a higher rate of side effects compared to aerosolized pentamidine 7.