Torrabadella L and Salgado G (2005) Controlled dose delivery in topical treatment of anal fissure: pilot study of a new paradigm. Dis Colon Rectum 49: 1–4

Topical nitroglycerin is a common treatment for anal fissure that reduces internal-sphincter tone and facilitates blood flow and healing. Previous studies have, however, shown variable efficacy and side effects (principally headache) of nitroglycerin in this setting. This variation might be caused, in part, by inaccurate placement and dosage of nitroglycerin associated with methods of administration (e.g. open tubular applicators or gloved fingers). Torrabadella and Salgado have compared the efficacy and safety of nitroglycerin administered either intra-anally, via a controlled dose-delivery device (DoseRite™, Origyn, Tustin, CA) plus side-opening applicator, or administered perianally via a gloved finger, in treatment-naive patients with anal fissure.

Consecutive patients were randomly allocated to receive 2.25 mg nitroglycerin three times daily, either intra-anally (n = 10)—with removal of excess nitroglycerin that leaked from the anal verge—or perianally (n = 12). Average duration of follow-up was 59.2 days and 36.4 days (intra-anal and perianal group, respectively; visits every 7–10 days). Clinical outcome (including fissure healing, sustained pain reduction, and referral for internal anal sphincterotomy) did not differ significantly between the groups. Intra-anal treatment was, however, associated with markedly fewer headaches (1 of 10 intra-anally treated patients versus 10 of 12 perianally treated) and greater reductions in resting anal pressure than perianal treatment. Headaches were so severe in seven perianally treated patients that they crossed over to the other group; six reported a subsequent improvement in their headaches.

The authors note that this drug delivery device might be useful in other disorders that require topical anal treatment.