Indefinite antimicrobial therapy

• Includes suppressive and prophylactic therapy, as well as use for treatment of non-infectious diseases (e.g. acne and reactive airways)

Indication	Antimicrobial	Alternative
Prophylaxis
PJP prophylaxis following transplantation	TMP-SMX SS or DS daily or thrice weekly	Dapsone 50-100 mg p.o. daily Atovaquone 1500 mg p.o. daily Pentamidine 300 mg inhaled every 3-4 weeks Clindamycin 300 mg p.o. daily plus pyrimethamine 15 mg p.o. daily
Post-splenectomy	Amoxicillin 250-500 mg p.o. daily
Rheumatic fever	Benzathine penicillin 1.2 g IM every 3-4 weeks Penicillin V 250 mg p.o. twice daily Sulphonamide 1 g p.o. daily Erythromycin 250 mg p.o. twice daily
Spontaneous bacterial peritonitis	Norfloxacin 400 mg p.o. daily	TMP-SMX DS p.o. daily Ciprofloxacin 750 mg p.o. weekly
Urinary tract infection	TMP-SMX SS half tablet p.o. daily or thrice weekly Trimethoprim 100-300 mg p.o. daily Ciprofloxacin 125 mg p.o. daily Cefalexin 125-250 mg p.o. daily Nitrofurantoin 50-100 mg p.o. daily Norfloxacin 200 mg p.o. daily
Suppressive Therapy
Prosthetic joint infection with MSSA	Cefalexin 500 mg p.o. three or four times daily Cefadroxil 500 mg p.o. twice daily	Dicloxacillin 500 mg p.o. three to four times daily Clindamycin 300 mg p.o. four times daily Amoxicillin/clavulanic acid 500 mg p.o. three times daily
Prosthetic joint infection with MRSA	TMP-SMX DS 1 tab p.o. twice daily	Minocycline or doxycycline 100 mg p.o. twice daily Fluoroquinolone +/- rifampin Fusidic acid + rifampin Cefalexin 500 mg p.o. three to four times daily
Prosthetic joint infection with beta-hemolytic streptococci and enterococci	Penicillin V 500 mg p.o. two to four times daily Amoxicillin 500 mg p.o. three times daily
Prosthetic joint infection with Gram-negative bacilli	Ciprofloxacin 250-500 mg p.o. twice daily TMP-SMX DS 1 tab p.o. twice daily
Non-Antimicrobial Properties
Acne	Minocycline 100 mg p.o. daily	Doxycycline, lymecycline, azithromycin, clindamycin, trimethoprim
Cystic fibrosis	Azithromycin 250-500 mg p.o. daily
Inflammatory bowel disease	Metronidazole 10-20 mg/kg/day Ciprofloxacin 500 mg p.o. twice daily plus metronidazole	RifaximinClarithromycin + rifabutin + clofazimine Clofazimine
Reactive airway disease	Azithromycin 250 mg p.o. daily Azithromycin 500 mg p.o. thrice weekly	Moxifloxacin 400 mg p.o. daily for 5 days followed by pulsed every 8 weeks

Further Reading

• Life-long antimicrobial therapy: where is the evidence? J Antimicrob Chemother. 2018;73:2601-2612. doi: 10.1093/jac/dky174