From the FDA Drug Label
Streptococcal Infections and Rheumatic Fever The sulfonamides should not be used for treatment of group A β-hemolytic streptococcal infections.
The FDA drug label does not answer the question regarding the effectiveness of Bactrim for urine culture growing beta hemolytic strep group B, as it only mentions group A β-hemolytic streptococcal infections. 1
From the Research
Bactrim (trimethoprim-sulfamethoxazole) is not the preferred treatment for urinary tract infections (UTIs) caused by beta-hemolytic strep group B due to high rates of resistance and the availability of more effective alternatives. According to the most recent study 2, the recommended first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females is a 5-day course of nitrofurantoin, a 3-g single dose of fosfomycin tromethamine, or a 5-day course of pivmecillinam.
- The typical dosage for uncomplicated urinary tract infections is one double-strength tablet (160mg trimethoprim/800mg sulfamethoxazole) twice daily for 3-5 days, or one regular-strength tablet (80mg/400mg) twice daily for 3-5 days.
- However, antibiotic susceptibility testing should guide treatment, as some strains may show resistance.
- Patients should take the full course of antibiotics even if symptoms improve, drink plenty of fluids, and contact their healthcare provider if symptoms worsen or don't improve within 48-72 hours.
- Those with sulfa allergies, pregnant women in their third trimester, or patients with certain kidney conditions should not take Bactrim, and alternative antibiotics would be needed.
- The use of Bactrim is not recommended due to its high resistance rates, as reported in the study 3, which highlights the importance of using alternative antibiotics to avoid resistance development.
- It is essential to note that the study 2 provides the most recent and highest quality evidence, and its recommendations should be prioritized in clinical practice.