Amitriptyline Dose and Treatment Outcomes in Specialty Headache Practice: A Retrospective Cohort Study.

OBJECTIVE: To characterize treatment patterns and real world outcomes in headache patients treated with amitriptyline in an academic headache center.

DESIGN AND METHODS: A retrospective chart review identified 178 patients in our center who were given a new prescription for amitriptyline in treatment of headache, and who were seen in follow-up within one year. Charts were reviewed to identify dosing patterns (initial and maximum dose) and persistence, patient-reported headache benefit, and reported side effects. Variables assessed in relation to medication use were comorbid psychiatric disease, headache characteristics, and prior use of a preventive medication.

RESULTS: We followed patients for an average of 6.5 months. Initial and maximum prescribed amitriptyline doses were characterized as: "very low" (≤10 mg daily), "low" (11-25 mg daily), and "traditional" (≥25 mg daily). The initial dose of amitriptyline ranged from 2.5 to 50 mg daily, though most patients were started on a dose of 10 mg daily (112/178, 63%). Approximately 3/4 of the patients were found to have improvement (134/178) and 85% (129/151) were still taking amitriptyline at the last follow-up appointment. Maximum dosing ranged from 2.5 to 100 mg daily with most patients taking 10-25 mg (86/146, 58%). The most commonly reported adverse effect was daytime fatigue (17/151, 11%). There did not appear to be any effect from gender, ethnicity, race, diagnosis of sleep apnea, chronicity of migraine, presence of aura on our outcome measures.

CONCLUSION: Our study supports the common clinical practice of using low doses of amitriptyline to treat chronic headache disorders and suggests that it was effective and well tolerated at doses lower than those used in many clinical trials. Use of low dosage amitriptyline may also improve medication persistence, an important clinical consideration in the management of this common and chronic condition. A subgroup of patients may experience a dramatic benefit from amitriptyline and this could warrant further investigation.