Doxycycline vs. Cotrimoxazole for Bacterial Infections

Comparative Efficacy

The World Health Organization recommends doxycycline (100mg twice daily) as first-line therapy for chlamydial and non-gonococcal urethritis, with azithromycin as an alternative, due to doxycycline's superior efficacy (100%) compared to azithromycin (97%) 1, 2
Doxycycline is recommended for purulent skin and soft tissue infections likely due to Staphylococcus aureus, including MRSA, by the Infectious Diseases Society of America 6
For community-acquired pneumonia, the American Thoracic Society suggests doxycycline can be used as an alternative to macrolides when combined with a β-lactam for inpatient therapy 7
Both doxycycline and ciprofloxacin have similar efficacy for post-exposure prophylaxis against Bacillus anthracis, according to the Infectious Diseases Society of America 8

The Centers for Disease Control and Prevention indicate that cotrimoxazole may have higher rates of adverse effects compared to some alternatives 1
Jarisch-Herxheimer-like reactions can occur during the first 24 hours of doxycycline therapy, as reported by the Infectious Diseases Society of America 9

For melioidosis, the British Society for Antimicrobial Chemotherapy notes that doxycycline had 80% survival rates while cotrimoxazole had 100% survival rates when used as post-exposure prophylaxis 10

For STIs (chlamydia, non-gonococcal urethritis), the European Society of Clinical Microbiology and Infectious Diseases recommends doxycycline 100mg twice daily for 7-14 days as the first choice 1, 2
For skin and soft tissue infections, the Infectious Diseases Society of America prefers doxycycline if MRSA is suspected 6
For respiratory infections, the American Thoracic Society suggests doxycycline can be used in combination with a β-lactam for community-acquired pneumonia 7