What is the best topical treatment for anal fissure?

Best Topical Treatment for Anal Fissure

Topical calcium channel blockers (such as diltiazem) are the most effective topical treatment for anal fissures, offering healing rates of 65-95% with fewer side effects compared to other topical agents. 1, 2

First-Line Treatment Approach

• Conservative management should be initiated first for all anal fissures, including fiber supplementation, adequate fluid intake, sitz baths, and topical analgesics 1
• About 50% of all anal fissures heal with conservative care alone, particularly acute fissures 1
• For fissures that don't respond to conservative management, topical treatments should be considered before surgical options 1

Topical Treatment Options (Ranked by Effectiveness)

1. Calcium Channel Blockers (First Choice)

• Topical calcium channel blockers (diltiazem or nifedipine) are as effective as glyceryl trinitrate but with significantly fewer side effects 1
• Healing rates of 65% have been reported with topical diltiazem compared to 38% with oral diltiazem 2
• No significant side effects reported with topical application, making it better tolerated than other options 2

2. Glyceryl Trinitrate (GTN)/Nitroglycerin

• Early studies showed promising healing rates of 70-80%, but more recent studies show lower rates of 25-50% 1
• Side effects, particularly headaches, occur in up to 77% of patients, often limiting treatment compliance 3, 4
• One study found that nitroglycerin "more often causes a headache than treats the symptoms of anal fissure" 4
• Long-term recurrence rates after initial healing can be high (67% at 9 months in one study) 3

3. Botulinum Toxin Injection

• High cure rates (75-95%) with low morbidity have been reported 1
• Works by causing temporary sphincter relaxation 1
• Optimal injection location (internal vs. external sphincter) remains controversial 1
• Limited long-term data on relapse rates and effects on continence 1

4. Topical Antibiotics

• Consider adding metronidazole to traditional therapies in cases of poor genital hygiene 1
• One study showed improved healing rates (86% vs 56%) when metronidazole was added to lidocaine 1
• Evidence is limited, and recommendation for antibiotic use is weak 1

Treatment Algorithm

1. Start with conservative management for 2 weeks (fiber, fluids, sitz baths, topical analgesics) 1
2. If no improvement after 2 weeks, add topical calcium channel blocker (diltiazem 2% gel twice daily) 2
3. If unavailable, consider glyceryl trinitrate 0.2% ointment twice daily, but warn about headache side effects 5
4. Consider botulinum toxin injection if topical treatments fail after 4-6 weeks 1
5. Consider surgical options (lateral internal sphincterotomy) only if non-operative management fails after 8 weeks 1

Important Considerations

• Atypical fissures (those not in the midline) require evaluation for underlying conditions such as Crohn's disease, HIV/AIDS, ulcerative colitis, or cancer 1
• Pain control is essential as it helps reduce the reflex spasm of the anal sphincter, enhancing healing 1
• Lidocaine is the most commonly prescribed topical anesthetic for pain relief 1
• In the United States, appropriate diluted GTN and topical calcium channel blocker preparations may not be commercially available and might need compounding 1

Cautions

• Manual dilatation should be avoided due to high risk of temporary and permanent incontinence (up to 30% and 10%, respectively) 1
• Surgical treatment should be avoided for acute fissures 1
• Long-term failure rates with topical therapy may be significant and require further study 1