Table 3 Adverse drug reactions (ADRs) leading to withdrawal and total ADRs reported*
ADRStage 1 Allopurinol(n = 82)Stage 2 Benzbromarone(n = 24)Stage 2 Probenecid(n = 31)
Number of patients with ADRs9 (11)/18 (22)1 (4)/5 (20)8 (26)/12 (39)
    95% CI5–20/14–320–19/6–3812–45/22–58
Type of ADR
    Dizziness–/––/–1 (3)/2 (6)
    Fatigue1 (1)/1 (1)–/–3 (10)/3 (10)
    Gastrointestinal1 (1)/6 (7)–/3 (12)5 (16)/7 (23)
    Gout flares†–/2 (2)1 (4)/2 (8)–/1 (3)
    Headache–/––/–1 (3)/2 (6)
    Muscle pain/cramps–/3 (4)–/––/–
    Rash6 (7)/6 (7)–/–1 (3)/1 (3)
    Flushing–/1 (1)–/–1 (3)/2 (6)
    Vision disorder1 (1)/1 (1)–/––/–
  • *ADRs expressed as ADR leading to withdrawal (n (%))/total ADR (n (%)) reported; one patient could report more than one ADR.

  • †Gout flares might be caused by starting serum urate (sUr)-lowering therapy due to mobilisation of urate related to rapid decline of sUr.