Can a 50-year-old Human Immunodeficiency Virus (HIV) positive patient with no known allergies be prescribed Bactrim (Trimethoprim/Sulfamethoxazole) DS?

From the Guidelines

Bactrim DS (trimethoprim-sulfamethoxazole) can be prescribed for a 50-year-old HIV-positive patient with no allergies. The standard prophylactic dose for preventing Pneumocystis jirovecii pneumonia (PCP) in HIV patients is one double-strength tablet (160 mg trimethoprim/800 mg sulfamethoxazole) daily or three times weekly 1. For active infections, the typical dose is one or two double-strength tablets twice daily for 7-14 days, depending on the infection being treated. This medication is particularly valuable for HIV patients as it provides protection against multiple opportunistic pathogens including PCP, toxoplasmosis, and certain bacterial infections. Some key points to consider when prescribing Bactrim DS include:

• Monitoring for side effects including rash, gastrointestinal disturbances, and electrolyte abnormalities 1
• Regular blood work to check renal function, liver enzymes, and complete blood count is recommended, especially during the first few weeks of treatment 1
• If the patient develops a rash or other signs of hypersensitivity, discontinue the medication immediately and consider alternative prophylaxis options such as dapsone, atovaquone, or pentamidine 1
• Desensitization protocols may be considered for patients with a history of hypersensitivity reactions to sulfonamides, including Bactrim DS 1

From the FDA Drug Label

Potential Risk in the Treatment of Pneumocystis jirovecii Pneumonia in Patients with Acquired Immunodeficiency Syndrome (AIDS) 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 sulfamethoxazole and trimethoprim 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 If a patient develops skin rash, fever, leukopenia or any sign of adverse reaction, re-evaluate benefit-risk of continuing therapy or re-challenge with sulfamethoxazole and trimethoprim

Key Considerations:

• The patient is HIV positive, which may increase the risk of adverse reactions to sulfamethoxazole and trimethoprim.
• The drug label warns of potential risks in treating Pneumocystis jirovecii pneumonia in AIDS patients, including increased incidence of adverse reactions.
• There is no information provided about the patient's current condition or the reason for prescribing Bactrim DS.

Answer: Bactrim DS can be prescribed to the patient, but with caution and close monitoring due to the potential increased risk of adverse reactions in HIV-positive patients 2.

From the Research

Patient Information

• Age: 50 years old
• HIV positive
• No allergies

Considerations for Prescribing Bactrim DS

• Bactrim DS is a combination of trimethoprim and sulfamethoxazole, which is commonly used to prevent Pneumocystis carinii pneumonia (PCP) in HIV-infected patients 3, 4, 5
• Studies have shown that trimethoprim-sulfamethoxazole is effective in preventing PCP and other bacterial infections in HIV-infected patients 4, 6, 5
• However, there is a risk of hypersensitivity reactions to trimethoprim-sulfamethoxazole, particularly in patients with a history of sulfa allergy 3
• The patient's HIV status and lack of allergies suggest that Bactrim DS may be a suitable option for prevention of PCP and other bacterial infections

Key Findings

• A study published in 1993 found that rechallenge with trimethoprim-sulfamethoxazole was safe in HIV-infected patients with a history of non-life-threatening hypersensitivity 3
• A study published in 1995 found that intermittent cotrimoxazole was more effective than low-dose dapsone for primary PCP prophylaxis 4
• A study published in 2002 found that trimethoprim-sulfamethoxazole significantly reduced the risk of bacterial infections, including infectious diarrhea, sinusitis/otitis media, and pneumonia, compared to aerosolized pentamidine and dapsone 6
• A review published in 2017 noted that trimethoprim-sulfamethoxazole remains the first-line agent for treatment and prophylaxis of Pneumocystis pneumonia in HIV-infected patients, despite concerns about resistance 7