Kara 2010.

Methods	Randomized, active‐controlled study, multiple dose, evaluated up to 2 days postop Medication administered at the end of the operation, without being contingent upon pain intensity Rescue medication (meperidine/pethidine 1 mg/kg IM) given to both groups as rescue medication for VAS > 4
Participants	Type of surgery: trans‐urethral resection of prostate Paracetamol group Entered/completing: 25/25 Age (mean, SD): only median age reported (64.3) Sex (male, %): 25 (100%) Diclofenac group Entered/completing: 25/25 Age (mean, SD): only median reported (66.8) Sex (male, %): 25 (100%)
Interventions	Paracetamol 1 g/100 ml IV over 15 min twice daily Diclofenac IM 75 mg at the end of the operation, followed by 75 mg IM for 24 h. Time interval between first two 75 mg doses not reported, but the authors describe this regimen as 150 mg once per day = 150 mg per 24 h.
Outcomes	Primary: pain intensity (VAS) Secondary: hemoglobin levels, hemostatic variables (bleeding time PT, INR), adverse effects, rescue opioid use (pethidine)
Source of funding	Not mentioned
Were treatment groups comparable at baseline?	Yes: demographics; duration of surgery; transrectal ultrasound volume
Details of preoperative pain	Similar at baseline
Notes	No statistically/clinically significant differences in postoperative hemoglobin, hemostatic parameters or bleeding events between placebo, paracetamol, and diclofenac groups. Diclofenac dosing (2 x 75 mg given in presumably quick succession, then repeated as a 150 mg dose 24 h later) is highly idiosyncratic, high. This regimen could bias results towards a greater diclofenac effect in the first portion of the 24 h dosing interval, and a lesser effect towards the end, compared with a more conventional dosing regimen of 75 mg IM every 12 h.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described
Allocation concealment (selection bias)	High risk	Not described. Assessed as high risk based on assumption of non‐blinding.
Blinding (performance bias and detection bias) All outcomes	High risk	Not described; assume to be unblinded
Incomplete outcome data (attrition bias) All outcomes	Low risk	No dropouts or protocol violations
Selective reporting (reporting bias)	Unclear risk	All outcomes from Methods section reported in Results section; opioid use reported in Results but not specifically mentioned in Methods. No SD reported for VAS data.
Size	High risk	Fewer than 50 participants per arm of the study (25 paracetamol, 25 diclofenac)