Oral amoxicillin as prophylaxis for endocarditis: what is the optimal dose?
We compared serum levels and tolerability of oral amoxicillin in 30 healthy adults who each received 2.0 g of amoxicillin and, 1 week later, 3.0 g of the same preparation. Serum levels of amoxicillin were determined at 1, 2, 4, and 6 hours following its ingestion. Mean serum levels of amoxicillin were significantly higher after 3.0-g doses than after 2.0-g doses. Levels in females were higher than in males; this was a reflection of differences in body weights. Food intake had no effect on serum levels. The 2.0-g doses resulted in adequate serum levels; 6 hours after dosing levels were still substantially higher than the MICs for oral streptococci. Three individuals (10%) experienced mild gastrointestinal side effects after they received the 3.0-g doses; no side effects were noted after the 2.0-g doses. We propose that to prevent bacterial endocarditis in adults who are at risk, a single 2.0-g dose of oral amoxicillin may be adequate prophylaxis for dental, oral, or upper respiratory tract procedures.
Dajani
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AS
Division of Infectious Diseases, Children's Hospital of Michigan, Detroit 48201.
Bawdon
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RE
Berry
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MC
D000284:Administration, Oral; D000328:Adult; D000658:Amoxicillin / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood; D004064:Digestive System / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004361:Drug Tolerance; D004697:Endocarditis, Bacterial / Q000517:prevention & control*; D005260:Female; D006801:Humans; D008297:Male
D000658:Amoxicillin