Oral nifedipine reduces resting anal pressure and heals chronic anal fissure

Background: Topical preparations have been used in the treatment of anal fissure. However, they are not universally successful and there is confusion over the site and dose of application. This study assessed the effectiveness of oral nifedipine in reducing resting anal pressure and on fissure healing. Methods: Anal manometry was performed on eight healthy volunteers and 15 patients with chronic anal fissure before and after oral administration of nifedipine 20 mg. Nifedipine was taken twice daily. Fissure healing was assessed over an 8-week period and pain scores were monitored. Results: Oral nifedipine produced an initial reduction in maximum resting anal pressure (MRP) of 35 per cent (P < 0.001) and of 28 per cent after 5 days (P < 0.001) in healthy volunteers. A reduction in IMRP of 36 per cent (P < 0.001) was observed in patients with fissure. Pain scores were significantly reduced during the treatment period. Healing was complete in nine patients after 8 weeks and a further three were asymptomatic. Ten patients experience flushing and four had mild headaches. There were no episodes of postural hypotension or incontinence. Conclusion: Oral nifedipine reduces resting anal pressure. It is well tolerated and offers an alternative treatment for chronic anal fissure.