From the Guidelines
For a wound culture positive for Staphylococcus aureus sensitive to Bactrim DS (trimethoprim-sulfamethoxazole), the recommended dosing is one double-strength tablet (800 mg sulfamethoxazole/160 mg trimethoprim) taken by mouth twice daily for 7-14 days, as supported by the most recent guidelines 1. The duration of treatment depends on the severity of the infection, with uncomplicated skin infections typically requiring 7-10 days of treatment, while deeper or more severe infections may need the full 14 days, as recommended by the Infectious Diseases Society of America 1. It is essential to take the medication with a full glass of water and to complete the entire course of antibiotics even if symptoms improve before the medication is finished, to prevent the development of antibiotic resistance and ensure complete eradication of the infection 1. Some key points to consider when taking Bactrim DS include:
- Taking the medication with food may reduce stomach upset
- Staying well-hydrated to prevent kidney complications
- Being aware of common side effects, such as nausea, vomiting, rash, and sun sensitivity, and taking sun protection measures as needed
- The mechanism of action of Bactrim DS, which involves inhibiting two consecutive steps in bacterial folate synthesis, necessary for bacterial DNA replication and growth, making it effective against many strains of S. aureus, including some methicillin-resistant strains 1. In terms of specific dosing, the guidelines recommend 1-2 double-strength tablets of Bactrim DS taken by mouth twice daily, with the exact dosage depending on the severity of the infection and the patient's response to treatment 1. Overall, the key to successful treatment of a wound culture positive for S. aureus with Bactrim DS is to complete the full course of antibiotics as prescribed, stay hydrated, and be aware of potential side effects, while also considering the severity of the infection and the patient's individual response to treatment 1.
From the FDA Drug Label
The usual adult dosage in the treatment of urinary tract infections is 1 sulfamethoxazole and trimethoprim DS (double strength) tablet or 2 sulfamethoxazole and trimethoprim tablets every 12 hours for 10 to 14 days The usual adult dosage in the treatment of acute exacerbations of chronic bronchitis is 1 sulfamethoxazole and trimethoprim double strength tablet, or 2 sulfamethoxazole and trimethoprim single strength tablets, every 12 hours for 14 days For the treatment of traveler’s diarrhea, the usual adult dosage is 1 sulfamethoxazole and trimethoprim DS (double strength) tablet or 2 sulfamethoxazole and trimethoprim single strength tablets every 12 hours for 5 days
The proper dosing for a wound culture positive for S. aureus sensitive to Bactrim DS 800/160 is 1 Bactrim DS tablet every 12 hours. The time frame for treatment is typically 10 to 14 days, but this may vary depending on the specific condition being treated. Since the drug label does not explicitly address wound infections, a conservative approach would be to follow the dosing guidelines for other infections, such as urinary tract infections or acute exacerbations of chronic bronchitis 2.
From the Research
Dosing Information for Bactrim DS 800/160
- The standard dose of trimethoprim-sulfamethoxazole (TMP/SMX) is 160 mg/800 mg twice daily for 7 to 15 days 3.
- A higher dose of TMP/SMX (320 mg/1,600 mg twice daily) for 7 to 15 days has been studied, but it did not show a significant difference in clinical resolution compared to the standard dose 3.
- The duration of treatment can vary depending on the severity of the infection and the clinical response of the patient.
Treatment Duration
- A study comparing 3-day and 10-day courses of TMP/SMX found that patients with methicillin-resistant Staphylococcus aureus (MRSA) infections were more likely to experience treatment failure and recurrent skin infection if given 3 days of antibiotics instead of 10 days 4.
- The treatment duration for skin and skin structure infections caused by MRSA is typically 7 to 15 days 3.
Efficacy of Bactrim DS 800/160
- TMP/SMX has been shown to be effective in treating infections caused by methicillin-sensitive Staphylococcus aureus (MSSA) and MRSA 5, 6, 7.
- However, vancomycin is generally considered superior to TMP/SMX in efficacy and safety for treating severe Staphylococcus aureus infections 5.
- TMP/SMX may be considered as an alternative to vancomycin in selected cases of MRSA infection 5, 7.