Acute sinusitis | Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis | Amoxicillin-clavulanate,1 875 mg orally twice daily for 10 days | For patients allergic to penicillin, doxycycline, 100 mg twice daily for 10 days |
Aspiration pneumonia | Mixed oropharyngeal flora, including anaerobes | Clindamycin, 300 mg orally four times daily for 10–14 days | Amoxicillin 500 mg orally three times daily for 10–14 days |
Cystitis | Escherichia coli, Staphylococcus saprophyticus, Klebsiella pneumoniae, Proteus species, other gram-negative rods or enterococci | Nitrofurantoin monohydrate macrocrystals 100 mg twice daily for 5–7 days (unless pregnant); fosfomycin 3 g orally as a single dose | Cephalexin, 500 mg orally four times daily for 7 days, for uncomplicated cystitis. Due to increasing bacterial resistance, TMP-SMZ and fluoroquinolones are not recommended as first-line therapy for empiric treatment |
Erysipelas, impetigo, cellulitis, ascending lymphangitis | Group A streptococcus | Penicillin V, 500 mg orally four times daily for 7–10 days | Cephalexin, 500 mg orally four times daily for 7–10 days; or azithromycin, 500 mg on day 1 and 250 mg on days 2–5 |
Furuncle with surrounding cellulitis | Staphylococcus aureus | Dicloxacillin, 500 mg orally four times daily for 7–10 days for MSSA. For CA-MRSA: TMP-SMZ2 one double-strength tablet twice daily for 7–10 days; or clindamycin 300 mg orally three times daily for 7–10 days | Cephalexin, 500 mg orally four times daily for 7–10 days for MSSA. For CA-MRSA, doxycycline is a reasonable alternative |
Gastroenteritis | Salmonella, Shigella, Campylobacter, Entamoeba histolytica | See footnote 3 | |
Otitis media | S pneumoniae, H influenzae, M catarrhalis | Amoxicillin, 500 mg–1 g orally three times daily for 10 days | Amoxicillin-clavulanate,1 875 mg orally twice daily; or cefuroxime, 500 mg orally twice daily; or cefpodoxime, 200–400 mg daily; or doxycycline, 100 mg twice daily |
Pelvic inflammatory disease | Neisseria gonorrhoeae, Chlamydia trachomatis, anaerobes, gram-negative rods | Ceftriaxone 250 mg intramuscularly once plus doxycycline 100 mg orally twice daily for 14 days +/– metronidazole 500 mg orally twice daily for 14 days; or cefoxitin 2 g intramuscularly once plus probenecid 1 g orally once, plus doxycycline 100 mg orally twice daily for 14 days +/– metronidazole 500 mg orally twice daily for 14 days | |
Pharyngitis | Group A streptococcus | Penicillin V, 500 mg orally four times daily, or amoxicillin, 500 mg–1 g orally three times daily for 10 days | For patients with history of mild penicillin allergy, cephalexin, 500 mg orally four times daily for 10 days; for patients with IgE-mediated reaction, clindamycin, 300 mg orally four times daily for 10 days; or azithromycin, 500 mg on day 1 and 250 mg on days 2–5 |
Pneumonia | S pneumoniae, Mycoplasma pneumoniae, Legionella pneumophila, Chlamydophila pneumoniae | Doxycycline, 100 mg orally twice daily | Amoxicillin, 1.0 g orally three times daily plus azithromycin 500 mg orally on day 1 and 250 mg on days 2–5. A respiratory fluoroquinolone4 for patients at high risk for infection due to resistant pneumococci |
Pyelonephritis | E coli, K pneumoniae, Proteus species, S saprophyticus | Fluoroquinolones5 for 7 days if prevalence of resistance among uropathogens is < 10% | TMP-SMZ,2 one double-strength tablet twice daily for 7–14 days for susceptible pathogens. Oral beta-lactams are less effective than fluoroquinolones or TMP-SMZ |
Urethritis, epididymitis | N gonorrhoeae, C trachomatis | Ceftriaxone, 250 mg intramuscularly once plus azithromycin (or doxycycline) for N gonorrhoeae; azithromycin 1 g orally once, or doxycycline, 100 mg orally twice daily for 7 days, for C trachomatis | Cefixime 400 mg orally once for N gonorrhoeae6 |
Syphilis |
Early syphilis (primary, secondary, or latent of < 1 year’s duration) | Treponema pallidum | Benzathine penicillin G, 2.4 million units intramuscularly once | Doxycycline, 100 mg orally twice daily for 2 weeks. Ceftriaxone 1–2 g intravenously once daily for 10–14 days |
Latent syphilis of > 1 year’s duration or cardiovascular syphilis | T pallidum | Benzathine penicillin G, 2.4 million units intramuscularly once a week for 3 weeks (total: 7.2 million units) | Doxycycline, 100 mg orally twice daily, for 4 weeks |
Neurosyphilis | T pallidum | Aqueous penicillin G, 18–24 million units/day intravenously for 10–14 days | |