Rectiv (Nitroglycerin) Dosing for Chronic Anal Fissure
Apply 375 mg of Rectiv (0.4% nitroglycerin ointment) intra-anally every 12 hours, delivering 1.5 mg of nitroglycerin per application, for a total daily dose of 3 mg. 1, 2
Standard Dosing Protocol
- Dose per application: 375 mg of 0.4% nitroglycerin ointment (1.5 mg active nitroglycerin) 1, 2
- Frequency: Twice daily (every 12 hours) 1, 2
- Route: Intra-anal application 1
- Total daily nitroglycerin dose: 3 mg 1
Treatment Duration and Expected Response
- Minimum treatment duration: 21 days, though most studies evaluate efficacy over 3-8 weeks 2, 3
- Pain relief timeline: Patients typically experience pain relief lasting 2-6 hours after each application 4
- Healing timeline: Complete fissure healing occurs within 2 weeks in approximately 50% of patients and within 4 weeks in an additional 10-15% 4, 3
- Maximum trial period: If no response after 6-8 weeks, consider alternative treatments or surgical referral 3, 5
Critical Administration Instructions
- Headache prophylaxis: Administer 650 mg acetaminophen before each nitroglycerin application to prevent treatment-limiting headaches 2
- Application technique: Apply directly to the anal canal, not just perianally 1
Important Clinical Considerations
Expected Side Effects
- Headache: Occurs in 70% of patients, severe enough to cause concern in 20-25% 1, 2
- Transient headache: Typically resolves despite continued therapy 4
- Local burning sensation: Mild and generally tolerable 3
Efficacy Limitations
Nitroglycerin is NOT the optimal first-line topical therapy. Compounded 0.3% nifedipine with 1.5% lidocaine cream achieves 95% healing rates compared to nitroglycerin's 60-70% healing rates, and nifedipine causes significantly fewer headaches. 6, 7 However, if Rectiv is the only available formulation or insurance requires it, the dosing above applies.
Mechanism of Action
- Nitroglycerin acts as a nitric oxide donor, mediating relaxation of the hypertonic internal anal sphincter 1
- Reduces anal canal pressure and improves anodermal blood flow to the ischemic fissure 1
- Bioavailability is approximately 50% with intra-anal application 1
Mandatory Adjunctive Measures
Nitroglycerin alone is insufficient. All patients must receive:
- High-fiber diet: 25-30 grams daily or fiber supplementation 7
- Adequate fluid intake: To soften stools and minimize anal trauma 8
- Warm sitz baths: Multiple times daily to promote sphincter relaxation 8
- Stool softeners: If constipation persists despite dietary measures 6
When to Abandon Nitroglycerin Therapy
- Severe intolerable headaches: Despite acetaminophen prophylaxis 2
- No improvement after 4 weeks: Consider switching to compounded nifedipine/lidocaine or surgical consultation 3
- No healing after 6-8 weeks: Classify as treatment failure and refer for lateral internal sphincterotomy 5, 3
Common Pitfalls to Avoid
- Stopping fiber and water intake after healing: This is the primary cause of fissure recurrence 8
- Using nitroglycerin as monotherapy: Without dietary modification and sitz baths, healing rates drop significantly 9
- Continuing beyond 8 weeks without response: This delays definitive surgical treatment that has >95% healing rates 5
- Inadequate headache prophylaxis: Failure to premedicate with acetaminophen leads to poor compliance 2