Risk of gout flare after medication: prescription symmetry sequence analysis.

• What is already known about this subject? 1. The prescription symmetry sequence analysis is a useful method for detecting an adverse drug reaction associated with one potential offending drug. 2. Numerous medications are found to induce gout flares. • What does this study add? 1. The prescription symmetry sequence analysis supports the evidence that aspirin (low-dose), thiazide diuretics, loop diuretics, ethambutol and pyrazinamide are associated with a greater probability of gout flares. 2. The exposure to fenofibrate or losartan might be a protective factor against gout flares. 3. Metformin use could be associated with a greater probability of gout flares. • How might this impact on clinical practice or future developments? 1. Clinicians should always consider the possibility of medication-induced gout flares. If gout flares develop, discontinuation of risky medications is the first step. Then prescribing cascades can be eliminated.