Clindamycin versus ampicillin in the treatment of odontogenic infections.

The subjects were 106 patients, aged 14 to 70 years, with acute facial or oral abscesses originating from an odontogenic source. They were randomly assigned to receive 150 mg of clindamycin or 250 mg of ampicillin orally four times daily for seven days. After seven days of treatment, the infections were eradicated in 36 of the 52 clindamycin-treated patients and in 42 of the 54 ampicillin-treated patients, and improved in 16 and 11, respectively. One of the ampicillin group was a treatment failure. Mixed bacterial infections were found in most of the patients; 385 isolates were identified, 167 aerobes and 218 anaerobes. The most common aerobes were Staphylococcus aureus (in 58 patients), Staphylococcus epidermidis (in 47), and Staphylococcus viridans (in 32); the most common anaerobes were species of Peptococcus (in 76), Bacteroides (in 38), and Peptostreptococcus (in 33). No isolates were resistant to clindamycin; nine of 126 aerobes and six of 160 anaerobes were resistant to ampicillin. It is concluded that clindamycin is a safe and effective alternative antibiotic in the treatment of odontogenic infections.