From the Guidelines
Bactrim (trimethoprim/sulfamethoxazole) can be used in patients with impaired renal function undergoing dialysis, but the dose should be adjusted to 50% of the normal dose, administered after dialysis sessions. This recommendation is based on the guidelines for preventing opportunistic infections among HIV-infected persons, which suggest that for patients on hemodialysis, the recommended dose of trimethoprim-sulfamethoxazole is ½ dose, administered after each dialysis session 1. Similarly, the guidelines for the management of chronic kidney disease in HIV-infected patients recommend a dosage adjustment for patients with creatinine clearance <15 mL/min to ½ dose or use of an alternative agent 1.
The need for dose adjustment stems from the fact that both trimethoprim and sulfamethoxazole components are partially removed during dialysis, and reduced kidney function in these patients leads to drug accumulation. Without proper adjustment, patients may experience increased side effects including hyperkalemia, bone marrow suppression, and worsening kidney function. Close monitoring is essential when using Bactrim in dialysis patients, particularly watching for signs of toxicity such as rash, blood count abnormalities, and electrolyte disturbances. Patients should be advised to report any unusual symptoms promptly.
Key considerations for using Bactrim in patients with impaired renal function undergoing dialysis include:
- Dose adjustment to 50% of the normal dose
- Administration of the adjusted dose after dialysis sessions
- Close monitoring for signs of toxicity
- Patient education on reporting unusual symptoms promptly Despite these considerations, when properly dosed, Bactrim remains an effective antibiotic option for treating susceptible infections in the dialysis population, as supported by the guidelines 1.
From the FDA Drug Label
However, patients with severely impaired renal function exhibit an increase in the half-lives of both components, requiring dosage regimen adjustment (see DOSAGE AND ADMINISTRATIONsection).
Use in patients with impaired renal function undergoing dialysis is not directly addressed.
- The label mentions that patients with severely impaired renal function require dosage regimen adjustment, but it does not provide specific guidance for patients undergoing dialysis.
- Caution is advised when using Bactrim (trimethoprim/sulfamethoxazole) in patients with impaired renal function, and dosage adjustments may be necessary.
- However, no conclusion can be drawn regarding the use of Bactrim in patients with impaired renal function undergoing dialysis, as the label does not explicitly address this scenario 2.
From the Research
Use of Bactrim in Patients with Impaired Renal Function Undergoing Dialysis
- Bactrim (trimethoprim/sulfamethoxazole) can be used in patients with impaired renal function undergoing dialysis, but with careful consideration of dosing and monitoring 3, 4.
- Renal dysfunction changes the pharmacokinetics of both trimethoprim and sulfamethoxazole, with significant alterations when creatinine clearance is less than 30 mL/min 3.
- Guidelines for appropriate dosing and monitoring of trimethoprim/sulfamethoxazole therapy in patients with impaired renal function are available 5, 3.
- Hemodialysis can remove significant amounts of trimethoprim and sulfamethoxazole, with 44% of administered trimethoprim and 57% of administered sulfamethoxazole removed during dialysis 4.
- Supplemental dosing of trimethoprim/sulfamethoxazole may be necessary after dialysis to maintain therapeutic levels 4.
Adverse Effects and Safety Considerations
- Adverse effects, including acute kidney injury, may occur more frequently in patients with impaired renal function 6.
- Patients with hypertension and diabetes mellitus may be at increased risk for renal insufficiency when treated with trimethoprim/sulfamethoxazole 6.
- Daily dosing of trimethoprim/sulfamethoxazole can be effective and safe in high-risk hemodialysis patients, with monitoring for clinical side effects and laboratory abnormalities 7.