Nitroglycerin was the first medicine shown to heal chronic fissures without surgery. It works, and it gives many patients a headache. That is why nifedipine and diltiazem exist.
In short: Nitroglycerin 0.2–0.4 % (Rectiv in the US, Rectogesic in the UK, Australia and Europe) heals about 50 to 65 % of chronic fissures at 8 weeks, but 20 to 30 % of patients get headaches and some stop treatment. Calcium channel blockers heal the same with fewer side effects.
Medically reviewed by Dra. Milagros Carla Quinto Cobeña, Cirugía general, especialista en proctología · CMP 53588 · RNE 30074 · Clínica Proctológica de Lima · Updated 2026-11-01
How it works
Nitroglycerin releases nitric oxide, the natural messenger that relaxes the internal sphincter. Applied to the anal canal, it lowers resting pressure for several hours and improves blood flow to the fissure.
The headache problem
Nitric oxide also dilates blood vessels in the head. Headache occurs in 20 to 30 % of patients, usually in the first minutes after application, and is the main reason for abandoning treatment. Starting with a smaller amount and applying after lying down reduces it; many surgeons simply prefer a calcium channel blocker from the start.
Alternatives with the same healing and fewer side effects
Diltiazem 2 % and nifedipine 0.2 to 0.3 % (with or without lidocaine) have shown equivalent healing in randomized trials with far fewer headaches. FISURIN uses nifedipine plus lidocaine for that reason.
Frequently asked questions
Can I use nitroglycerin if I take sildenafil or similar?
No. Nitrates combined with sildenafil, tadalafil or vardenafil can cause a dangerous drop in blood pressure, even with topical use. Tell your physician; a calcium channel blocker is the alternative.
This content is educational and does not replace a medical consultation. FISURIN is a magistral (compounded) formula prepared under prescription in an authorized pharmacy; availability and regulatory status vary by country. If you have bleeding that does not stop, fever, or pain that worsens, seek medical care without delay.
