From the Guidelines
Bactrim (Trimethoprim/Sulfamethoxazole) Prophylaxis in HIV-Positive Individuals To use Bactrim (trimethoprim/sulfamethoxazole) prophylactically in HIV-positive individuals, the recommended dose is one single-strength tablet (80mg trimethoprim/400mg sulfamethoxazole) daily 1. This is typically used to prevent Pneumocystis jirovecii pneumonia (PCP) and other opportunistic infections.
- The duration of prophylaxis depends on the individual's CD4 cell count and viral load, but generally, it is recommended for those with a CD4 count below 200 cells/mm^3 1.
- Alternative regimens can be considered for patients who cannot tolerate TMP-SMZ, including dapsone, dapsone plus pyrimethamine plus leucovorin, aerosolized pentamidine, and atovaquone 1.
- It is essential to consult a healthcare provider for personalized guidance, as they will assess the individual's specific needs and health status to determine the appropriate duration and potential need for alternative prophylactic regimens.
- Patients who have experienced adverse events, including fever and rash, might better tolerate reintroduction of the drug with a gradual increase in dose (i.e., desensitization) or reintroduction of TMP-SMZ at a reduced dose or frequency 1.
From the FDA Drug Label
For the treatment of documented Pneumocystis jirovecii pneumonia and for prophylaxis against P jirovecii pneumonia in individuals who are immunosuppressed and considered to be at an increased risk of developing P. jirovecii pneumonia.
Adults: The recommended dosage for prophylaxis in adults is 4 teaspoonfuls (20 mL) of sulfamethoxazole and trimethoprim oral suspension daily.
Children: For children, the recommended dose is 750 mg/m 2/day sulfamethoxazole with 150 mg/m 2/day trimethoprim given orally in equally divided doses twice a day, on 3 consecutive days per week
The prophylactic use of Bactrim (Trimethoprim/Sulfamethoxazole) in patients with Human Immunodeficiency Virus (HIV) is for the prevention of Pneumocystis jirovecii pneumonia. The recommended dosage for prophylaxis in adults is 4 teaspoonfuls (20 mL) of sulfamethoxazole and trimethoprim oral suspension daily 2. For children, the recommended dose is 750 mg/m 2/day sulfamethoxazole with 150 mg/m 2/day trimethoprim given orally in equally divided doses twice a day, on 3 consecutive days per week 2.
From the Research
Prophylactic Use of Bactrim in HIV Patients
The prophylactic use of Bactrim (Trimethoprim/Sulfamethoxazole) in patients with Human Immunodeficiency Virus (HIV) is primarily for the prevention of Pneumocystis carinii pneumonia (PCP) [ 3 ].
Efficacy and Safety
- A study published in 1991 found that low-dose trimethoprim-sulfamethoxazole thrice weekly was efficacious for primary and secondary prophylaxis of PCP in HIV-infected patients [ 3 ].
- The failure rate for primary prophylaxis was 2.9% and for secondary prophylaxis was 7.4% [ 3 ].
- Adverse reactions sufficient to permanently terminate therapy occurred in 8.7% of patients [ 3 ].
Potential Risks
- A 2012 study found that trimethoprim/sulfamethoxazole can cause acute psychosis in HIV-infected patients with Pneumocystis jirovecii pneumonia, with an incidence of 11.9% [ 4 ].
- The risk of acute psychosis increased with higher daily doses of trimethoprim/sulfamethoxazole and the use of adjunctive steroids [ 4 ].
Comparison with Other Studies
- A 2024 study compared low-dose and conventional-dose trimethoprim-sulfamethoxazole for Pneumocystis pneumonia in non-HIV patients and found similar survival rates but reduced adverse events with low-dose treatment [ 5 ].
- A 2011 systematic review found weak evidence that trimethoprim-sulfamethoxazole prophylaxis protects against resistance to other antibiotics [ 6 ].
General Information
- Trimethoprim-sulfamethoxazole is active against a variety of gram-positive and gram-negative bacteria and is useful for treatment and prophylaxis of various infections [ 7 ].
- It is the antimicrobial agent of choice for Pneumocystis carinii pneumonia and is relatively nontoxic in patients without AIDS [ 7 ].