Penicillin treatment in oral surgery in patients with coagulation disorders.

There are clinical observations indicating that the frequency of postoperative bleeding after oral surgery in patients with coagulation disorders is reduced by prophylactic antibiotic treatment. To assess this effect, the concentrations of phenoxymethylpenicillin in plasma and saliva were determined during treatment and compared with the MIC values for penicillin of the oral bacteria of four patients with coagulation disorders. The concentration of penicillin in plasma of the patients considerably exceeded the MIC values of all isolated bacteria. In mixed saliva and saliva of the parotid and submandibular glands no penicillin activity could be detected. The bacteria isolated from the oral cavity of the patients did not in vitro exhibit either fibrinolytic or plasminogen activator activity. Thus, the oral bacteria of patients with coagulopathies probably do not cause an increased bleeding tendency by their intra- or extracellular enzymes.