Study	Treatment	Adverse events	Withdrawals
Arnold 2016	Intervention group (N = 54): flexible‐dose pregabalin 75 to 450 mg/day Control group (N = 53): flexible‐dose placebo 75 to 450 mg/day Study duration: 15 weeks' duration involving 4 phases: doses were optimised over 3 weeks based on efficacy and tolerability to 75, 150, 300, 450 mg/day. Remaining at that dose for 12 weeks.	Total adverse events: Pregabalin: 167 Placebo: 132 No. participants with any adverse event: Pregabalin: 38/54 Placebo: 34/53 No. participants with serious adverse events: Pregabalin: 1/54 Placebo: 0/53	Total all‐cause withdrawals: Pregabalin: 10/54 Placebo: 17/53 Withdrawals due to adverse events: Pregabalin: 4/54 Placebo: 4/53
Brown 2016	Intervention group (N = 17): oral gabapentin 900 mg/day (300 x 3) Control group (N = 17): oral amitriptyline 10 mg/day Study duration: 6 weeks	Total adverse events: Gabapentin: 2/17 Amitriptyline: 1/17 No. participants with any adverse event: Gabapentin: 2/17 Amitriptyline: 1/17 No. participants with serious adverse events: Gabapentin: 0/17 Amitriptyline: 0/17	Total all‐cause withdrawals: Gabapentin: 2/17 Amitriptyline: 3/17 Withdrawals due to adverse events: Gabapentin: 2/17 Amitriptyline: 1/17
CI: confidence interval; m: mean; N: number of participants; SD: standard deviation