Ozyalcin 2005.

Methods	Single‐centre, double‐blind, randomised, parallel study: venlafaxine 75 mg versus venlafaxine 150 mg versus placebo
Participants	Country: Turkey N = 60 Sex: 6 M, 54 F Mean age: 34.25 (SD 8.28) venlafaxine 75 mg; 37.19 (SD 12.37) venlafaxine 150 mg; 38.16 (SD 11.24) placebo Diagnosis: migraine without aura according to International Headache Society (IHS 1988) Exclusion criteria: age < 18 or > 70, headache for < 2 years, < 3 attacks or > 10 attacks per month and > 15 headache days per month. Patients taking other prophylactic treatment not stopped 2 weeks prior the start of the study. Women who were breast feeding, patients with major cardiovascular, metabolic, gastrointestinal, neurologic diseases, any primary headache disorder other than migraine without aura, and any secondary headache disorder including drug over use headache disorder
Interventions	N = 20 venlafaxine 75 mg N = 21 venlafaxine 150 mg N = 19 placebo
Outcomes	1. Number of days with headache 2. Pain intensity 3. Headache duration 4. Analgesic consumption 5. Daily activities 6. Patient satisfaction 7. Adverse events 8. Global tolerance
Notes	Lost at follow‐up 22% (47 completers) Per protocol analysis No sample size calculation
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No information (randomised)
Allocation concealment (selection bias)	Unclear risk	No information
Blinding (performance bias and detection bias) All outcomes	Unclear risk	No information (double‐blinded)
Incomplete outcome data (attrition bias) All outcomes	Low risk	Moderate drop‐out rate (13/60 = 21.67%), balanced (placebo 3/19 = 15.8%, venlafaxine 75 mg 5/20 = 25%, venlafaxine 150 mg 5/21 = 23.8%)
Selective reporting (reporting bias)	Unclear risk	No information
Other bias	High risk	Grant from Wyeth Ilaclari AS, Istanbul, Turkey. Blinded study drugs were prepared by Wyeth Pharmaceuticals, PA, USA