Abstract: We included four RCTs, involving 564 participants in this review. We compared the effects of colchicine in addition to a non-steroidal anti-inflammatory drug (NSAID) such as ibuprofen, aspirin or indomethacin to the effects of the NSAID alone. Two comparable trials studied the effects of colchicine in 204 participants with recurrent pericarditis and two trials studied 360 people with acute pericarditis. All trials had a moderate quality for the primary outcomes. We identified two on-going trials; one of these trials examines acute pericarditis and the other assesses recurrent pericarditis. There was moderate quality evidence that colchicine reduces episodes of pericarditis in people with recurrent pericarditis over 18 months follow-up (HR 0.37; 95% confidence interval (CI) 0.24 to 0.58). It is expected that at 18 months, the number needed to treat (NNT) is 4. In people with acute pericarditis, there was moderate quality evidence that colchicine reduces recurrence (HR 0.40; 95% CI 0.27 to 0.61) at 18 months follow-up. Colchicine led to a greater chance of symptom relief at 72 hours (risk ratio (RR) 1.4; 95% CI 1.26 to 1.56; low quality evidence). Adverse effects were mainly gastrointestinal and included abdominal pain and diarrhoea. The pooled RR for adverse events was 1.26 (95% CI 0.75 to 2.12). While the number of people experiencing adverse effects was higher in the colchicine than the control groups (9% versus 7%), the quality of evidence was low owing to imprecision, and there was no statistically significant difference between the treatment groups (P = 0.42). There was moderate quality evidence that treatment with colchicine led to more people stopping treatment due to adverse events (RR 1.87; 95% CI 1.02 to 3.41). Colchicine, as adjunctive therapy to NSAIDs, is effective in reducing the number of pericarditis recurrences in patients with recurrent pericarditis or acute pericarditis. However, evidence is based on a limited number of small trials. Patients with multiple resistant recurrences were not represented in any published or on-going trials, and it is these patients that are in the most need for treatment.

Plain-language summary: We wanted to discover whether colchicine alone or added to other medications is better or worse than alternative therapies in preventing pericarditis. We have reviewed all randomised controlled trials about the effect of colchicine in preventing recurrence of pericarditis in people with pericarditis. We found four trials involving 564 participants, who were followed up for at least 18 months. Two studies examined the use of colchicine in people with recurrent pericarditis and two examined the use of colchicine in people with a first episode of pericarditis. The evidence is current to August 2014. The trials showed that people taking colchicine have a lower risk of developing pericarditis recurrence and a higher proportion experience symptom relief. It is expected that at 18 months, one pericarditis recurrence can be avoided for every four people receiving colchicine with NSAIDs rather than NSAIDs alone. Adverse effects were reported in all trials and affected 15 people (9%) of the 162 taking colchicine. Adverse effects included abdominal pain, nausea and vomiting. Two studies were designed so that participants knew the type of intervention they were taking and people in the comparison group had no dummy pill. The results of these studies could exaggerate the effects of the drug. The evidence suggests beneficial effects of colchicine in preventing recurrence of pericarditis, however this is based on a limited number of small trials. More trials are currently being done and we await their results to see if the benefits of colchicine can be further confirmed.