Should a patient with untreated Human Immunodeficiency Virus (HIV) infection and a CD4 (Cluster of Differentiation 4) count of 210 cells/μL be placed on trimethoprim/sulfamethoxazole (Bactrim)?

From the Guidelines

No, a patient with untreated HIV and a CD4 count of 210 cells/mm³ should not be started on Bactrim (trimethoprim-sulfamethoxazole) for Pneumocystis jirovecii pneumonia (PCP) prophylaxis, as the CD4 count is above the recommended threshold of 200 cells/mm³. According to the guidelines for preventing opportunistic infections among HIV-infected persons, prophylaxis is indicated when CD4 counts fall below 200 cells/mm³, as this represents a significant risk threshold for opportunistic infections, particularly PCP 1. The medication works by inhibiting folate synthesis in susceptible organisms. For patients with sulfa allergies, alternative options include dapsone 100 mg daily, aerosolized pentamidine 300 mg monthly, or atovaquone 1500 mg daily. While initiating antiretroviral therapy should be the primary goal to restore immune function, PCP prophylaxis remains essential until the CD4 count rises above 200 cells/mm³ for at least 3-6 months on stable antiretroviral therapy. Regular monitoring of complete blood counts is recommended due to potential bone marrow suppression with Bactrim.

Some key points to consider:

• The guidelines recommend chemoprophylaxis against PCP if the CD4+ T lymphocyte count is less than 200 cells/mm³ 1
• Trimethoprim-sulfamethoxazole (TMP-SMZ) is the recommended prophylactic agent, with a preferred regimen of one double-strength tablet per day 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
• The decision to start PCP prophylaxis should be based on the individual patient's risk factors and CD4 count, rather than a single threshold value 1

From the FDA Drug Label

AIDS patients may not tolerate or respond to sulfamethoxazole and trimethoprim in the same manner as non-AIDS patients The incidence of adverse reactions, particularly rash, fever, leukopenia and elevated aminotransferase (transaminase) values, with sulfamethoprim therapy in AIDS patients who are being treated for P. jirovecii pneumonia has been reported to be increased compared with the incidence normally associated with the use of sulfamethoxazole and trimethoprim in non-AIDS patients

The decision to put a patient with untreated HIV on Bactrim (trimethoprim/sulfamethoxazole) depends on the CD4 count and the presence of any opportunistic infections.

• CD4 count of 210: This is not considered a low CD4 count that would automatically warrant prophylactic Bactrim for Pneumocystis jirovecii pneumonia (PCP).
• However, the FDA drug label does not provide a specific CD4 count threshold for initiating Bactrim prophylaxis in HIV patients.
• Clinical guidelines typically recommend Bactrim prophylaxis for PCP when the CD4 count falls below 200 cells/mm^3 2. Based on the information provided, it is not possible to make a definitive recommendation, but in general, a CD4 count of 210 would not typically be considered an indication for Bactrim prophylaxis in the absence of other risk factors or clinical indications.

From the Research

Patient with Untreated HIV and CD4 Count of 210

• The patient's CD4 count is 210, which is above the threshold of 200 cells/microl typically considered for Pneumocystis jirovecii pneumonia (PCP) prophylaxis 3, 4, 5.
• However, the patient has untreated HIV, which increases the risk of opportunistic infections 3, 6, 5.
• Studies have shown that trimethoprim-sulfamethoxazole (TMP-SMZ) is effective in preventing PCP and other bacterial infections in patients with advanced HIV infection 3, 4, 5.
• One study found that TMP-SMZ significantly reduced the risk of any bacterial infection, including infectious diarrhea, sinusitis/otitis media, and pneumonia, compared to other prophylactic agents 5.
• Another study demonstrated that TMP-SMZ is the most effective agent for PCP prophylaxis in people with HIV and confers a mortality benefit 4.
• However, it is essential to note that these studies were conducted in patients with more advanced HIV infection (CD4 count < 200 cells/microl) 3, 5.
• There is limited evidence specifically addressing the use of TMP-SMZ in patients with untreated HIV and a CD4 count of 210 7.
• One study suggested that PCP prophylaxis may not be necessary in patients with sustained viral suppression, regardless of CD4 count 7.

Considerations for Bactrim (TMP-SMZ) Prophylaxis

• The decision to initiate Bactrim prophylaxis should be based on individual patient factors, including the risk of opportunistic infections and the potential benefits and harms of treatment 6.
• Patients with untreated HIV and a CD4 count of 210 may still be at risk for opportunistic infections, and the use of Bactrim prophylaxis should be considered on a case-by-case basis 3, 6, 5.