Paper Title
Amitriptyline Effects on Serum Glutamate and Pain Intensity in Chronic Tension-Type Headache Patients

Abstract
Amitriptyline has been widely used for prophylactic pharmacotherapy in patients with chronic tension-type headache (CTTH). The aim of the present study was to determine if there were alterations in the serum levels of glutamate and pain intensity in CTTH patients before and after 15-day treatment with amitriptyline. This randomized, controlled, double-blind, clinical trial with pre and post test design included 73 patients with diagnosis of CTTH according to International Classification of Headache Disorders, 2nd edition criteria. All subjects were randomized into three interventional groups (flunarizine 5 mg/day, twenty five patients; flunarizine 10 mg/day, twenty five patients; amitriptyline 12.5 mg/day, twenty three patients). The serum level of glutamate and Numeric Rating scale (NRS) score for pain intensity were measured before and after 15-day treatment. We found significant difference decrement of serum glutamate concentration (p <0.001) between baseline and after 15-day in flunarizine 5 mg group and the NRS score decreased significantly (p<0.001) was found in amitriptiline 12.5 mg group. In the present study, flunarizine showed more effective in reducing serum glutamate concentration whereas amitriptyline more effective in reducing pain intensity and this suggest that glutamate play a role in the patophysiology of CTTH. Key words- Flunarizine, serum glutamate, CTTH patients, NRS score