Chronic anal fissures are a painful condition frequently seen in general practice, with an incidence of 2,5/1000 per year. According to the practice guidelines of the Dutch College of General Practitioners, isosorbide dinitrate 1% ointment (ISDN) is the treatment of first choice for chronic anal fissures. Systemic side-effects such as headache are reported in 27% of all cases. This side effect in combination with the frequent application of ISDN (4-6 times daily) leads to a low compliance for this therapy. A meta-analysis of the Cochrane Collaboration showed similar efficacy of diltiazem compared to ISDN. Diltiazem has several advantages: the application frequency is only twice daily, no systemic side-effects have been reported, the total costs of treatment are lower than the costs of ISDN and a standard preparation of diltiazem ointment is available. Therefore, diltiazem 2% ointment should be the first line treatment for chronic anal fissures.
Conflict of interest: none declared. Financial support: none declared.