Topical nitrates potentiate the effect of botulinum toxin in the treatment of patients with refractory anal fissure.

BACKGROUND: Anal fissure is perpetuated by high sphincter pressures and secondary local ischaemia. Pharmacological approaches include topical nitrates and botulinum toxin (BT) which act to reduce anal pressure. BT lowers anal pressure by preventing acetylcholine release from nerve terminals while topical nitrates act by donating nitric oxide (NO). The aims of the present study were to compare the therapeutic effect and lowering action on internal anal sphincter pressure of BT injection and local application of isosorbide dinitrate (ID) compared with BT given alone, in patients with chronic anal fissure (CAF) refractory to treatment with ID. METHODS: Thirty consecutive patients with CAF who did not respond to previous topical ID treatments were randomly assigned to receive one of the following treatments: group A, injection of BT (20 U into the internal anal sphincter) and subsequent daily applications of ID (2.5 mg three times daily for three months); and group B, BT injection only (20 U). If at the end of six weeks following BT injection no improvement was seen in group B, ID was added. A series of anal pressure measurements, including resting basal pressure and resting pressure following topical ID (1.25, 2.5, and 3.75 mg), was carried out both before and two weeks after 20 U of BT injection into the internal anal sphincter. At the end of the trial, patients were followed up for an average period of 10 months. FINDINGS: At six weeks the fissure healing rate was significantly higher in group A patients (10/15 (66%)) compared with group B (3/15 (20%)) (p=0.025). At eight and 12 weeks, no significant differences were seen: 11/15 (73%) v 11/15 (73%) and 9/15 (60%) v 10/15 (66%), group A v group B, respectively. Maximum anal resting pressure (MARP) was significantly lower two weeks after BT injection than baseline MARP (90 (4) v 110 (5) mm Hg; p<0.001). A significantly greater reduction in MARP following local application of ID was achieved after BT injection compared with that achieved before BT injection (p=0.037) INTERPRETATION: (1) Combined BT injection and local application of ID in patients with CAF who failed previous treatment with ID was more effective than BT alone. This treatment modality appears to be safe and promising. (2) ID application induced a greater reduction in MARP following BT injection compared with ID application before BT injection. The improved potency of ID on MARP after BT injection suggests a primary cholinergic tonus dominance in some patients and not, as previously claimed, anal sphincter insensitivity to nitrates.

Treatment of chronic anal fissure with isosorbide dinitrate: long-term results and dose determination.

PURPOSE: Anal fissure is a tear of the anoderm, which eventually can become an ulcer. Chronic anal fissure is perpetuated by contraction of the internal sphincter, believed to reduce perfusion. Nitric oxide is a neurotransmitter mediating vasodilation and internal anal sphincter relaxation. The aim of the present study was to evaluate both the effect and the effective dose regimen of isosorbide dinitrate, a nitric oxide donor, as a treatment for chronic anal fissure. METHODS: Isosorbide dinitrate, Isoket spray (Schwarz-Pharma, Mannheim, Germany), was used to treat 41 patients with chronic anal fissure. Anal manometry was performed in all patients before they entered the study. The treatment program consisted of digital application of isosorbide dinitrate in a dose of 1.25 mg or 2.5 mg three times each day for four weeks. At the end of the trial, patients were followed up for an average time of 11 +/- 1 months. RESULTS: In 34 (83 percent) patients, the fissure healed within one month of treatment (mean, 3 +/- 0.1 weeks). The average time for symptoms to disappear was 6.5 +/- 0.7 days. In six (14.6 percent) patients the anal fissure did not heal even after four weeks of further treatment, and they underwent lateral sphincterotomy. Six patients relapsed during the follow-up period, but responded to another course of treatment. A dose of 2.5 mg of isosorbide dinitrate caused a greater reduction in maximum anal resting pressure than a dose of 1.25 mg. CONCLUSIONS: Topical isosorbide dinitrate is an effective and safe treatment for chronic anal fissure. In our experience the optimal dose regimen is 2.5 mg three times each day.

Decreased substance P content in the rectal mucosa of diabetics with diarrhea and constipation.

Substance P (SP), vasoactive intestinal polypeptide (VIP), and somatostatin content in rectal mucosa were determined by radioimmunoassay (RIA) in 38 diabetic patients (12 with normal bowel function, 13 with diabetic diarrhea, and 13 with constipation) and in 10 nondiabetic controls with normal bowel function. SP content (picograms per milligram) in the rectal mucosa of diabetics with normal bowel function was significantly higher than that of nondiabetic controls (P < .05). SP content in the rectal mucosa of diabetics with diabetic diarrhea and constipation was significantly lower than in diabetics with normal bowel habits and nondiabetic controls (P < .05). No differences were found in the rectal mucosa content of VIP and somatostatin between the different groups of diabetics and controls. Diabetic diarrhea is a condition with an intermittent nature and frequently alternates with constipation. Our findings showing low levels of rectal mucosa SP in both conditions suggest a possible common role of SP in the pathogenesis of diabetic diarrhea and constipation.