Oral bioavailability of antimicrobials

Antimicrobial	Bioavailability
Ciprofloxacin	70%
Levofloxacin	99%
Trimethoprim-sulfamethoxazole	100%
Amoxicillin	70-80%
Amoxicillin-clavulanic acid	70-80%
Cephalexin	95%
Cefadroxil	90%
Cefpodoxime	46%
Cefdinir	25%

• Note that oral dosing for many medications (e.g. β-lactams) is much lower for oral than for IV formulations, so even a high bioavailability may not guarantee that target levels in serum are reached

Excellent Bioavailability (>90%)

• Ciprofloxacin
• Doxycycline
• Fluconazole
• Levofloxacin
• Linezolid
• Metronidazole
• Minocycline
• Moxifloxacin
• Rifampin
• Trimethoprim-sulfamethoxazole
• Voriconazole

Good Bioavailability (60-90%)

• Amoxicillin
• Azithromycin
• Cephalexin
• Cefuroxime axetil
• Ciprofloxacin
• Clindamycin
• Erythromycin