Valproic Acid-Induced Thrombocytopenia-Related Spontaneous Systemic Bleeding

Area of Science:

• Neurology
• Hematology
• Pharmacology

Background:

• Valproic acid is a widely used medication for various conditions.
• Thrombocytopenia is a known, but often dose-dependent, side effect of valproic acid.
• High protein binding of valproic acid influences its therapeutic and toxic levels.

Observation:

• A 57-year-old woman developed spontaneous oral and vaginal bleeding.
• She presented with atraumatic contusions, ecchymosis, and a subdural hematoma.
• Laboratory tests revealed severe thrombocytopenia (platelets 4000/μL) with subtherapeutic valproic acid levels (26.3 μg/mL).

Findings:

• This case presents spontaneous systemic bleeding secondary to valproic acid-induced thrombocytopenia.
• It is the first reported instance of such bleeding occurring with normal fibrinogen levels.
• The event occurred despite the patient having subtherapeutic serum valproic acid concentrations.

Implications:

• Clinicians should consider valproic acid-induced thrombocytopenia in patients presenting with unexplained bleeding, even with seemingly low drug levels.
• This case underscores the potential for serious hematologic adverse events with valproic acid, irrespective of typical therapeutic ranges.
• Further investigation into the mechanisms and clinical relevance of valproic acid-induced thrombocytopenia is warranted.