Penicillin-induced coagulation disorder.

A coagulation disorder was seen after penicillin-G administration (10 million units/day) in uraemic patients and after high-dose penicillin G (40 million units/day) in patients with a normal glomerular filtration-rate (5 patients after cardiac surgery). This disorder was characterised by: prolongation of bleeding-time, appearing immediately after penicillin-G administration and persisting until 4 days after withdrawal of therapy; disturbance of collagen-induced and ristocetin-induced platelet aggregation; increase of antithrombin-III activity; and inhibition of factor-xa activity. The inhibition of factor-xa activity corresponded to that seen after low-dose-heparin prophylaxis. The clinically latent coagulation disorder, when super-imposed upon pre-existing coagulation abnormalities (uraemia, treatment with anti-coagulants) may cause severe bleeding, as observed in 1 patient with acute renal failure on haemodialysis.