How To Apply Nitroglycerin Ointment For Fissures

If your doctor has prescribed nitroglycerin ointment, you are probably wondering how to apply nitroglycerin ointment for fissures correctly, and what to expect once you start. The application itself is simple, but a few details make a real difference to how it goes.

South Fork Pharmacy in Moorefield, WV fills prescriptions like this and counsels patients on them, and one theme comes up every time: people are surprised by the side effects. This article covers what the ointment is for, general application guidance, why headaches are so common, and what to do if the side effects are hard to tolerate. It is general information only. Your prescriber’s directions and the label on your prescription always come first.

What Nitroglycerin Ointment Is Used For

Nitroglycerin ointment is prescribed for chronic anal fissures, which are small tears in the lining of the anal canal that do not heal on their own. In many people with a fissure, the internal anal sphincter, the ring of muscle inside the anus, is tight and stays in spasm. That tightness pinches off blood flow to the tear, so it struggles to heal, and each bowel movement can reopen it.

Nitroglycerin works by relaxing that muscle. When the sphincter relaxes, blood flow to the fissure improves and the tissue has a better chance to heal. It is a prescription treatment, and it is not something to obtain or use without a doctor’s evaluation, since other conditions can look similar to a fissure and the right treatment depends on the correct identification of the problem. Prescription strengths and formulations vary, so use only what was prescribed for you.

How It’s Typically Applied

Directions differ between products and prescribers, so the specific instructions on your label take priority over anything you read here. In general, the ointment is applied in a small, measured amount, often a strip of a specific length, once or twice a day for a limited number of weeks. Some prescriptions direct application at the anal opening and others just inside the canal, so ask your prescriber or pharmacist to confirm exactly where yours goes.

A few general habits are widely recommended. Wash your hands before and after. Because nitroglycerin absorbs through the skin, many people use a disposable glove, a finger cot, or a piece of plastic wrap over the finger so the medication does not soak into the fingertip, which can itself cause headaches. Use only the measured amount, since more does not heal a fissure faster and increases side effects. Clean and pat dry the area first, and apply it at the times your prescriber gave you, commonly morning and evening.

Sitting or lying down for a few minutes after applying can help if you feel lightheaded. Store the tube as directed, keep it tightly closed, and keep it out of reach of children and pets. If you miss a dose, follow the instructions on the label or ask your pharmacist rather than doubling up.

Healing takes time, and it is worth setting expectations. Treatment is usually given for a limited course of several weeks, and your prescriber will want to see how the fissure responds. Pain during and after bowel movements often improves before the tear has fully healed, so the ointment may seem to be working before the treatment ends. Keep any follow-up appointments, and let your prescriber know if the pain is not improving or if you notice more bleeding.

Why Headache Is A Common Side Effect

Nitroglycerin is a vasodilator, which means it widens blood vessels. The same effect that relaxes the sphincter and improves blood flow to the fissure also happens, to a lesser degree, in blood vessels elsewhere in the body once some of the medicine is absorbed. Widened blood vessels in and around the head are a classic cause of headache.

A headache from this ointment is not a sign that something is wrong or that you are using it incorrectly. It is a predictable effect of how the medication works, and it is one of the most commonly reported side effects. It is still worth knowing about in advance, so it does not catch you off guard, and so you can tell the difference between an expected headache and one that needs attention.

How Common And Predictable The Headache Really Is

Many fissure-treatment articles mention headache in a single line, which undersells how often it happens. In clinical studies of nitroglycerin ointment for fissures, headaches were among the most frequent complaints, reported by a large share of people, and for some they were significant enough that they stopped treatment. That does not mean everyone gets one, but it does mean you should plan on the possibility rather than treating it as rare.

The headache typically begins shortly after application, often within the first hour, and may last for a few hours. It tends to be most noticeable in the first days and may ease as the body adjusts, though that varies from person to person. Applying the ointment at times when you can rest, such as at bedtime, and using only the prescribed amount can help.

Pain relievers are worth discussing with your pharmacist or doctor rather than assuming. Ask which one is safe for you given your other medications and health conditions. And tell your prescriber about the headaches, since they may adjust the plan. Never change the amount or frequency of a prescription on your own, ask your doctor.

Other Side Effects To Expect

Beyond headache, the same vasodilation can cause lightheadedness, dizziness, and a drop in blood pressure, especially when you stand up quickly. Some people notice a flushed face, a fast heartbeat, or weakness. Local effects such as burning, itching, or irritation at the application site can also occur.

Because of the blood pressure effect, take extra care getting up from sitting or lying down, and be cautious with driving or operating machinery until you know how the ointment affects you. Alcohol can add to the effect, so many prescribers advise caution with it.

One important safety point: tell your prescriber and pharmacist about every medication you take. Nitroglycerin should not be combined with certain erectile dysfunction and pulmonary hypertension medications, such as sildenafil, tadalafil, and vardenafil, or with riociguat, because the combination can cause a dangerous drop in blood pressure. If you have heart problems, low blood pressure, anemia, or increased pressure in the head, or if you are pregnant or breastfeeding, make sure your prescriber knows. Seek emergency help by calling 911 if you faint, have chest pain, or a severe reaction.

What To Do If Side Effects Are Hard To Tolerate

If the headaches or dizziness are more than you can manage, do not simply stop or adjust the dose alone. Call the prescribing doctor. They may adjust the plan, review timing, or consider a different treatment, and there are several other approaches to fissures they can discuss, from other medications to procedures.

Your pharmacist is also a resource. They can review your medication list for interactions, explain how to apply the ointment to minimize absorption through your fingers, and help you plan around headaches. Bring your questions and the tube to the counter, and we can go over it with you. You can reach us through our pharmacy services page, and our medication information section has more general reading.

Alongside any prescription, the basics still matter for fissures: soft stools from fiber and fluids, avoiding straining, and warm sitz baths, which many people find soothing. If pain is severe, if there is heavy bleeding, or if a fissure has not healed within the time your doctor expected, let them know.

Frequently Asked Questions

Can I buy nitroglycerin ointment for a fissure without a prescription?

No, it is prescription-only, and it should be used only under a doctor’s direction. If you think you have a fissure, see a doctor for a proper evaluation.

Why does nitroglycerin ointment give me a headache?

It widens blood vessels, including some near the head, which is a common cause of headache. It is an expected effect, but tell your prescriber if it is severe.

How long does the headache last?

It often starts within an hour of applying and can last a few hours, and it may ease as your body adjusts. Ask your prescriber or a pharmacist at South Fork Pharmacy if it does not.

Should I wear a glove when applying it?

Many people use a glove, finger cot, or plastic wrap to avoid absorbing it through the fingertip. Ask your pharmacist or prescriber what is right for your product.

Can I stop using it if the headaches are bad?

Call your prescribing doctor before stopping or changing the amount. They can adjust the plan or discuss alternatives.

Why do I feel dizzy after applying it?

Nitroglycerin can lower blood pressure, especially when you stand up quickly. Sit or lie down, get up slowly, and call your doctor or 911 if you faint or have chest pain.