Evidence of safety: relative risk and 95% confidence intervals
| Comparison | Adverse events | RR* (95% CI) | Evidence | Reference |
|---|---|---|---|---|
| *RR: relative risk between treatment group and control group: RR = 1, no difference; RR >1, more risk with treatment; RR <1, more risk with control. | ||||
| AHS, allopurinol hypersensitivity syndrome; CI, confidence interval; CT, controlled trial; FPE, fixed pigmented drug eruption; GI, gastrointestinal; LCV, leucocytoclastic vasculitis; RCT, randomised controlled trial. | ||||
| Colchicine v placebo | Nausea, vomiting or diarrhoea | 4.20 (1.95 to 9.03) | RCT, 48 hours | 17 |
| Diarrhoea | 8.38 (1.14 to 61.38) | RCT, 3 months | 22 | |
| Colchicine+probenecid v probenecid | Any | 1.69 (0.95 to 3.00) | RCT, 6 months | 23 |
| GI | 1.69 (0.95 to 3.00) | RCT, 6 months | 23 | |
| Diarrhoea | 1.35 (0.60 to 3.04) | RCT, 6 months | 23 | |
| Nausea/vomiting | 1.98 (0.85 to 4.60) | RCT, 6 months | 23 | |
| Azapropazone v allopurinol | Acute duodenal ulcer | 2.20 (0.09 to 53.59) | CT, 6 months | 24 |
| Nausea/dyspepsia | 51.68 (3.21 to 833.18) | CT, 6 months | 24 | |
| Diarrhoea/abdominal pain | 2.20 (0.23 to 20.85) | CT, 6 months | 24 | |
| Headache/dizziness | 1.10 (0.19 to 6.47) | CT, 6 months | 24 | |
| Allopurinol: | ||||
| Allopurinol v placebo | Creatinine clearance | Reduced to p>0.02 | RCT, 2.5 years | 13 |
| Adjusted dose v unadjusted dose | Rash, AHS, FPE, LCV | 1.96 (0.34 to 11.92) | Cohort study, | 44 |
| Exposure v non-exposure | Cataract | 1.82 (1.18 to 2.80) | Case–control | 45 |