Background: The anal fissure is one of the most common anorectal diseases that is associated with reduced quality of life and productivity loss. We aimed to compare the efficacy of topical nifedipine and diltiazem for the treatment of acute anal fissure (AAF).
Methods: This single-blind randomized clinical trial was conducted at Ziaeian hospital, Tehran. Patients with an acute fissure diagnosis were allocated to two groups. Group A applied 3 grams of 0.3% nifedipine cream on the peri-anal area, three times a day, for 8 weeks. Group B also applied the same amount of 2% diltiazem-ointment on the peri-anal area for the same period. The primary outcome was fissure remission in the 8th week of the treatments. The duration of pain relief, the side effect of treatment, and the recurrence rate were also compared between the groups.
Results: After 8 weeks of treatment, a remission rate of 77.4% was shown in the nifedipine group which was significantly higher than the diltiazem group with a remission rate of 54% (P=0.01). Applying nifedipine ointment is associated with earlier pain relief compared with diltiazem (P<0.001). After 6 months of follow-up, the relapse rate was not statistically different between the nifedipine and diltiazem groups (16.3% versus 21.4%, respectively).
Conclusion: The application of topical nifedipine is associated with shorter pain relief and more remission rate for AAF compared with topical diltiazem. However, both methods were not different in terms of related side effects and AAF recurrence rate.
Keywords: Diltiazem, Nifedipine, Acute anal fissure

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10404091/pdf/mejdd-15-121.pdf