Circulating thrombin time anticoagulant in a procainamide-induced syndrome

Area of Science:

• Pharmacology
• Hematology
• Immunology

Background:

• Drug-induced syndromes can rarely manifest with circulating anticoagulants.
• Procainamide is an antiarrhythmic drug with potential adverse effects.
• Understanding the mechanisms of drug-induced coagulopathies is crucial for patient safety.

Observation:

• A patient with procainamide-induced syndrome exhibited a prolonged thrombin time.
• This coagulation defect was attributed to a circulating anticoagulant not originating from fibrin or fibrinogen.
• The anticoagulant prolonged both thrombin and reptilase clotting times.

Findings:

• Subclinical doses of heparin sodium precipitated hemorrhagic manifestations in the patient.
• The circulating anticoagulant remained detectable even after heparin therapy was discontinued.
• Bleeding tendency resolved upon cessation of heparin, while the anticoagulant persisted.

Implications:

• The study highlights an unusual case of drug-induced circulating anticoagulant.
• It suggests a complex interaction between procainamide, anticoagulants, and bleeding risk.
• Gradual resolution of all symptoms after procainamide withdrawal underscores the drug's causal role.