Defective platelet function following the administration of penicillin compounds

Area of Science:

• Pharmacology
• Hematology
• Clinical Medicine

Background:

• Penicillin antibiotics are widely used clinically.
• Potential side effects on hemostasis are not fully understood.
• Platelet function is crucial for blood clotting.

Purpose of the Study:

• To investigate the effects of penicillin-G, ampicillin, and methicillin on platelet function and blood coagulation in humans.
• To determine dose-dependent effects and identify specific alterations in hemostasis.

Main Methods:

• Human volunteers received incremental doses of penicillin-G, ampicillin, or methicillin.
• Platelet aggregation (ADP-induced), coagulation tests, and bleeding time were assessed.
• Intracellular adenine nucleotide content was measured.

Main Results:

• Coagulation tests remained normal across all drug groups.
• ADP-induced platelet aggregation was impaired by penicillin-G and ampicillin, and to a lesser extent by methicillin.
• Dose-dependent prolongation of bleeding time occurred with penicillin-G and ampicillin, but not methicillin.
• Platelet adenine nucleotide levels were unaffected.

Conclusions:

• Penicillin-G and ampicillin interfere with ADP-mediated platelet activation, leading to impaired aggregation and prolonged bleeding.
• Methicillin exhibits a lesser impact on platelet function and bleeding time compared to penicillin-G and ampicillin.
• These findings highlight potential risks of certain penicillin derivatives in patients with bleeding disorders.