At a glance
People with chronic anal fissures often try more than one topical medication during their treatment journey. Each works by relaxing the internal sphincter muscle, but the side effect profiles and daily experience of using them differ. Understanding these differences can help you have a more informed conversation with your clinician about which option might suit you.
This guide compares the three main topical fissure medications from the perspective of what people actually describe about using each one.
The three main options
GTN (glyceryl trinitrate)
Brand names include: Rectogesic, Rectiv
How it works: Releases nitric oxide to relax smooth muscle.
What people describe:
- Effective at reducing sphincter spasm
- The headache side effect is the dominant feature of the experience
- Headaches can be severe — ranging from mild and brief to debilitating
- Some people adjust to the headaches over time; others do not
- The headaches are dose-related — less ointment means less headache, but also potentially less effectiveness
- Application stinging is common
Diltiazem
How it works: Blocks calcium channels in smooth muscle, reducing contraction.
What people describe:
- Significantly fewer headaches than GTN
- Some people describe a mild burning on application
- A small number develop a local skin reaction (rash, irritation)
- Generally well tolerated for most people
- Similar effectiveness to GTN for many
- Often prescribed when GTN headaches are intolerable
Nifedipine
How it works: Another calcium channel blocker, similar mechanism to diltiazem.
What people describe:
- Similar to diltiazem in terms of headache frequency (less than GTN)
- May cause less local skin reaction than diltiazem for some people
- Mild dizziness is occasionally reported
- Less widely prescribed than GTN or diltiazem in some regions
- An alternative when diltiazem is not tolerated
Comparing the practical experience
Headaches
- GTN: Common and often significant. The primary reason people switch away.
- Diltiazem: Less common. When they occur, typically milder.
- Nifedipine: Similar to diltiazem. Occasionally present, rarely severe.
Skin reactions
- GTN: Stinging on application. Skin reactions less common.
- Diltiazem: Some people develop a local rash or irritation. The most common reason for switching from diltiazem.
- Nifedipine: Generally well tolerated. Less commonly associated with skin reactions.
Application experience
- All three involve applying a small amount of ointment to the anal canal
- The process is similar regardless of the medication
- The discomfort of application is related to the fissure itself, not the specific cream
- Applying after a sitz bath reduces discomfort for all three
Effectiveness
- The evidence suggests similar effectiveness across the three medications
- Individual response varies — some people respond to one but not another
- Compliance matters as much as choice of medication — a cream you can tolerate is better than one you cannot use consistently
The switching experience
People who switch between medications describe:
- Relief when moving from a poorly tolerated cream to a better-tolerated one
- A brief period of uncertainty about the new medication
- Usually a smooth transition — one is stopped and the other started
- The importance of giving each new medication a fair trial (several weeks)
Beyond topical treatment
If none of the topical medications heal the fissure after adequate trials, the next step is typically:
- Botox injection
- Surgery (LIS or fissurectomy)
Not responding to topical treatment does not mean the fissure is untreatable. It means it needs a different approach.
When to seek care
Contact your clinician if:
- Side effects are making it impossible to use the prescribed cream
- Symptoms are not improving after a full course of treatment
- Heavy or persistent bleeding
- Pain that is worsening
- You want to discuss switching or escalating treatment