Is nitroglycerin (glyceryl trinitrate) effective for a patient with a second anal fissure?

Nitroglycerin for Recurrent Anal Fissure

Yes, nitroglycerin (glyceryl trinitrate) can help heal a second anal fissure, but calcium channel blockers like diltiazem or nifedipine are more effective with fewer side effects and should be your first-line topical treatment. 1

Why Calcium Channel Blockers Are Preferred Over Nitroglycerin

According to the most recent systematic review and meta-analysis of 148 trials, calcium channel blockers (CCBs) were more effective than glyceryl trinitrate and caused significantly less headache and hypotension. 1

Comparative Effectiveness:

• CCBs (diltiazem or nifedipine) achieve healing rates of 65-95% 1
• Nitroglycerin achieves healing rates of only 25-50% 1
• In head-to-head comparison, topical nifedipine healed 89% of chronic fissures versus only 58% with glyceryl trinitrate 2

Side Effect Profile:

• Headaches occur in 40-72% of patients using nitroglycerin 2, 3, 4
• Only 5% of patients experience side effects with topical nifedipine 2
• Headaches are severe enough to limit treatment in approximately 15% of nitroglycerin users 3

If You Choose to Use Nitroglycerin

Dosing and Application:

• Apply 0.2% glyceryl trinitrate ointment twice daily to the anoderm for at least 6 weeks 1
• Use 1.5-2 cm of ointment per application 5
• Pain relief typically occurs within 14 days, but complete healing takes longer 1

Expected Outcomes:

• Nitroglycerin reduces maximum anal resting pressure from approximately 122 to 72 cm of water within 20 minutes 6
• For acute fissures: 63% heal by 4 weeks, 81% by 8 weeks 3
• For chronic fissures: 33% heal by 8 weeks, 50% by 12 weeks 3
• Recurrence rates are significant: 25-43% of healed fissures recur 2, 4

Complete Treatment Algorithm for Second Fissure

Step 1: Conservative Management (Always Start Here)

Non-operative management is strongly recommended as first-line treatment for anal fissures, including recurrent ones. 1

• Increase fiber intake and water consumption 1
• Warm sitz baths to relax the internal anal sphincter 1
• Topical analgesics for pain control 1
• 50% of fissures heal with conservative measures alone within 10-14 days 1

Step 2: Add Topical Sphincter Relaxant

If conservative measures fail after 2 weeks, add topical therapy: 1

• First choice: Topical calcium channel blocker (0.3% nifedipine with 1.5% lidocaine or diltiazem) 1
• Second choice: 0.2% glyceryl trinitrate ointment if CCBs unavailable 1
• Continue treatment for at least 6 weeks 1

Step 3: Consider Botulinum Toxin

If topical therapy fails, botulinum toxin injection shows 75-95% cure rates with low morbidity 1

Step 4: Surgical Options (Last Resort)

Lateral internal sphincterotomy is reserved for fissures that fail all conservative and medical management 1

Critical Pitfalls to Avoid

What NOT to Do:

• Never perform manual dilatation—it carries 30% temporary and 10% permanent incontinence rates 1
• Do not rush to surgery for a second fissure—repeat the conservative approach first 1

Important Caveats:

• Since this is a recurrent fissure, ensure adequate duration of initial conservative therapy (full 6 weeks minimum) 1
• Address underlying causes: constipation, inadequate fiber/fluid intake, or sphincter hypertonicity 1
• If the fissure is not in the midline (posterior or anterior), evaluate for Crohn's disease or other underlying conditions 7, 8

Monitoring for Chronicity:

Look for signs that indicate chronic fissure requiring more aggressive treatment: 7, 8

• Sentinel skin tag
• Hypertrophied anal papilla
• Visible internal sphincter muscle fibers
• Duration beyond 8 weeks despite treatment