Comparison between two low doses of Amitriptyline in the management of chronic neck pain. A Randomized double-blind comparative study.

INTERVENTION: 10 mg Amitriptyline dose 5 mg of amitriptyline. CONDITION: ; Musculoskeletal Diseases ; Nervous System Diseases ; Orthopaedics Musculoskeletal Diseases Nervous System Diseases Orthopaedics PRIMARY OUTCOME: Neck Pain Disability Index. NPDI SECONDARY OUTCOME: Anxiety and depressive symptoms will be evaluated with Hospital Anxiety and Depression Scale (HADS), Athens Insomnia Scale Neck pain intensity INCLUSION CRITERIA: 1. Presence of CNP for more than 15 days/month during at least three consecutive months. 2. Patients without previous trauma. 3. Patients free from other neurologic disorders except for chronic tension headaches. 4. Age from18 to 75 years. 5. Normal neurologic examination (performed by a neurologist) except for pericranial tenderness. 6. No imaging abnormalities except for a loss of cervical lordosis.