Should an alternative antibiotic be considered for a patient with a lower abdominal abscess, currently experiencing copious drainage, after completing a 7-day course of Bactrim (trimethoprim/sulfamethoxazole)?

From the Guidelines

For a patient with an improving but still draining abdominal abscess who has completed a 7-day course of Bactrim, I would recommend switching to clindamycin 300mg orally four times daily for 7-10 days while awaiting culture results. Clindamycin provides good coverage against common skin and soft tissue pathogens, particularly Staphylococcus aureus (including some MRSA strains) and anaerobes that might be contributing to the persistent drainage, as suggested by the Infectious Diseases Society of America guidelines 1. Alternatively, doxycycline 100mg twice daily for 7-10 days could be considered, especially if MRSA is suspected, given its bacteriostatic properties and limited recent clinical experience 1. The patient should continue warm compresses to the area 3-4 times daily to promote drainage and healing. Proper wound care with daily cleaning and application of a clean, dry dressing is essential. If the patient develops increasing pain, redness, fever, or the abscess appears to be worsening rather than improving, they should return for reevaluation as surgical drainage or incision might be necessary. The switch to a different antibiotic class is recommended because the persistent drainage despite Bactrim therapy suggests either resistant organisms or inadequate coverage of the causative pathogens, as noted in the guidelines for the management of skin and soft tissue infections 1. It's also important to consider the potential for MRSA and the need for antibiotics with activity against this pathogen, such as clindamycin or doxycycline, as recommended by the guidelines 1. Overall, the goal is to provide effective treatment while minimizing the risk of antibiotic resistance and promoting optimal patient outcomes.

From the Research

Alternative Antibiotic Options

The patient has completed a 7-day course of Bactrim and still experiences copious drainage, surrounding redness, and improved swelling/abscess formation. Considering alternative antibiotic options, the following points are relevant:

• According to 2, the bacterial targets for antibiotics are mainly Staphylococcus aureus (SA) and Streptococcus pyogenes, and amoxicillin + clavulanate is recommended as the first-line antibiotic in most children suffering from severe skin infections requiring antibiotic treatment.
• A study by 3 found that treatment with a "simple" antibiotic, such as cephalexin, will result in resolution of the infection in nearly all cases of uncomplicated soft tissue infections.
• The use of oral tetracyclines, such as doxycycline, minocycline, and omadacycline, is recommended for the treatment of adult outpatients with skin and soft infections, including acute bacterial skin and skin structure infections (ABSSSIs) 4.
• A decision-analytic approach by 5 suggests that clindamycin and trimethoprim/sulfamethoxazole (T/S) have a higher probability of activity against the bacteria causing the infection, including CA-MRSA, methicillin-sensitive S. aureus, and group A Streptococcus (GAS).
• A study by 6 found that doxycycline and trimethoprim-sulfamethoxazole are effective against MRSA and should be used as initial therapy for SSTI when MRSA is suspected.

Key Considerations

When selecting an alternative antibiotic, consider the following:

• The prevalence of CA-MRSA and antibiotic resistance profiles in the local community 5, 6.
• The effectiveness of the antibiotic against the suspected pathogens, including Staphylococcus aureus and Streptococcus pyogenes 2, 3.
• The use of oral tetracyclines, such as doxycycline, minocycline, and omadacycline, as recommended for the treatment of adult outpatients with skin and soft infections 4.