• valproic acid;
  • migraine;
  • refractory headache;
  • treatment;
  • prophylaxis

Objective– The efficacy and safety of valproic acid were assessed as a prophylactic agent in migraine patients who previously derived no significant benefit from conventional prophylactic medications for migraine. Patients and methods– One hundred and twenty patients aged 23–58 years with the diagnosis of migraine without aura. Response to therapy was determined by using a headache calendar detailing the frequency and severity of attacks. Reduction of 50% or greater in the frequency or severity of headache was considered as improvement. Results– Improvement was observed in headache frequency within 67% of patients. Headache severity had been improved in 60% of patients. The mean average dosage of valproic acid was 1250 mg daily. Most of the side effects are mild and tolerable. Conclusion– These results suggest that valproic acid is effective and safe in the treatment of refractory migraine headache.