Table 1. Activity of Antimicrobial Agents Against Oral Microorganisms

Penicillin Use oral penicillin V as it results in higher plasma levels than oral penicillin G.
Amoxicillin Achieves higher serum concentrations than oral penicillin V; recommended in prophylaxis of dental infections.
Cephalexin Not recommended in prophylaxis/treatment of dental infections. >90% of Viridans Group Streptococci are resistant to cephalexin.
Cefuroxime Good activity against most dental pathogens.
Macrolides Less activity against dental pathogens compared to β-lactam agents.

Ciprofloxacin/ Levofloxacin/


Not recommended in prophylaxis/treatment of dental infections.
Clindamycin Due to significant risks of adverse effects including C. difficile infection (highest risk of any other antibiotic class) and significant resistance of oral flora, clindamycin use should be restricted to documented allergy/intolerance to all other recommended agents.
Metronidazole No aerobic coverage; use in combination with penicillin.
Doxycycline/ Tetracycline Anti-inflammatory properties may have role in periodontal infections.