WHAT IS THIS MEDICINE AND WHAT IS IT USED FOR?
Rectogesic contains glyceryl trinitrate (GTN) — the same active
ingredient used in angina sprays and patches, but in a low-concentration
ointment form applied locally to treat anal fissures. An anal fissure is a
small tear in the lining of the anal canal, usually caused by passing a hard or
large stool.
Although small, fissures can cause intense pain — particularly during and
after a bowel movement — and a persistent spasm of the internal anal sphincter
muscle (the ring of muscle around the anus). This muscle spasm reduces blood
flow to the fissure, preventing it from healing.
GTN ointment releases nitric oxide, which relaxes the internal anal
sphincter — relieving the spasm, improving blood flow, and allowing the fissure
to heal. It is used to relieve the pain of chronic anal fissures and promote
healing.
3. HOW TO TAKE THIS MEDICINE
Apply a small amount of ointment (approximately 2.5cm of ointment — about
1 inch measured from the tube) to the anal area twice daily — morning and
evening. Do not apply inside the anus (rectally) — apply externally around the
anal margin only, or as directed. Use the finger cot (fingertip cover, if
provided) or the tip of a clean finger. Wash hands thoroughly before and after
application.
Treatment is typically continued for 8 weeks. Do not use more than
directed — headaches are common even at the prescribed dose and worsen with
larger amounts.
Measure the dose carefully — approximately 2.5cm (1 inch) of ointment
from the tube. Applying more than this significantly increases the risk of
headache and low blood pressure. Keep the tube tightly closed between uses. The
ointment should not be applied inside the rectum — just to the outside of the
anal opening and the surrounding skin.
⚠ PATIENT TIP: Headaches are the most common
side effect — affecting up to 50% of patients. They are usually mild to
moderate and improve after the first week or two as your body adjusts. If the
headache is very troublesome, try paracetamol. Applying the ointment after a
bowel movement (rather than before) can sometimes reduce peak blood levels and
lessen headaches.
4. POSSIBLE SIDE EFFECTS
|
How Common? |
Side Effects |
|
Very Common |
Headache — affects up
to half of all patients, especially in the first 1 to 2 weeks. Usually
improves with continued use as tolerance develops. |
|
Common |
Dizziness, flushing,
feeling faint or light-headed (particularly when standing up from sitting or
lying — low blood pressure effect) |
|
Less Common |
Burning or discomfort
at the application site (usually temporary), nausea, palpitations |
|
Serious — Stop and
Seek Medical Advice |
Severe persistent
hypotension (very low blood pressure — if you feel faint or collapse after
application). Severe skin reaction at application site. |
5. WHO SHOULD NOT TAKE THIS MEDICINE
Rectogesic must not be used by patients who are taking
phosphodiesterase-5 inhibitors (PDE5 inhibitors) for erectile dysfunction or
pulmonary hypertension — including sildenafil (Viagra), tadalafil (Cialis),
vardenafil (Levitra), and avanafil. The combination causes a sudden, severe,
potentially life-threatening drop in blood pressure.
Do not use in patients with severe anaemia, closed-angle glaucoma, or
raised intracranial pressure. Use with caution in patients with very low blood
pressure, aortic/mitral stenosis, or hypertrophic cardiomyopathy.
⚠ PDE5 INHIBITOR CONTRAINDICATION (VIAGRA, CIALIS, LEVITRA):
This is an absolute contraindication. Combining GTN-based products with PDE5
inhibitors can cause a catastrophic and potentially fatal drop in blood
pressure. If you take sildenafil, tadalafil, or similar medicines, do not use
Rectogesic — speak to your doctor about alternative fissure treatments.
⚠ LOW BLOOD PRESSURE RISK: GTN dilates blood vessels
throughout the body, not just locally. Stand up slowly after applying,
particularly if you feel dizzy. Avoid strenuous activity immediately after
application.
⚠ HEADACHES: These are a sign the medicine is being absorbed
and working — mild to moderate headaches in the first 1 to 2 weeks are normal
and expected. They usually improve. If severe and persistent, contact your GP.
6. MEDICINES THAT INTERACT WITH THIS TREATMENT
Absolutely contraindicated with PDE5 inhibitors (sildenafil, tadalafil,
vardenafil, avanafil) — severe hypotension risk. Significantly increased
hypotension risk with: other nitrates (GTN sprays, patches, isosorbide
mononitrate), antihypertensive medicines, alcohol, and other vasodilators.
Tricyclic antidepressants may reduce the effect of GTN. Heparin activity may be
reduced by GTN — monitor anticoagulation if relevant.
7. HOW TO STORE THIS MEDICINE
Store below 25°C. Keep the tube tightly closed. Do not refrigerate. Keep
out of reach of children. Once opened, use within the period stated on the
tube.
8. PRESCRIPTION REQUIREMENT
|
Field |
Details |
|
Status |
Prescription Only
Medicine (POM) — prescribed by GPs or colorectal surgeons |
9. GUIDANCE FOR PATIENTS & CAREGIVERS
Apply approximately 1 inch (2.5cm) of ointment from the tube to the
outside of the anal area, twice daily — morning and evening. Wash hands
carefully before and after. Do not apply inside the anus. If you experience
headaches, paracetamol can help — they usually improve after the first 1 to 2
weeks. Stand up slowly after applying, as the medicine can temporarily lower
your blood pressure. If you take Viagra (sildenafil), Cialis (tadalafil), or
any similar medicine for erectile dysfunction or heart/lung conditions, do not
use this ointment — tell your doctor to prescribe an alternative fissure
treatment.
10. PHARMACIST & PRESCRIBER NOTES
|
Field |
Details |
|
Clinical Dispensing
Notes |
GTN 0.4% rectal
ointment — absolute contraindication with PDE5 inhibitors (sildenafil,
tadalafil, vardenafil, avanafil). Screen all male patients for PDE5 inhibitor
use at dispensing. Dose application technique counselling: 2.5cm from tube,
external application only around anal margin, not intrarectal. Headache
counselling: very common (up to 50%), typically transient and self-limiting
within 2 weeks; paracetamol is appropriate. Orthostatic hypotension risk —
advise slow position change post-application. Concurrent nitrate and
antihypertensive interaction counselling. Treatment course typically 8 weeks
— review non-healing or worsening symptoms for colorectal specialist
referral. Lifestyle adjuncts: high-fibre diet, adequate fluid intake, stool
softeners — address constipation as root cause. |
11. FREQUENTLY ASKED QUESTIONS
Q: How exactly do I apply the ointment?
Wash your hands. Squeeze approximately 2.5cm (about 1 inch) of ointment
from the tube onto your fingertip or the applicator provided. Gently apply it
to the external anal area — the skin around the opening, not inside. Wash your
hands thoroughly afterwards. Do not insert the ointment inside the rectum.
Q: How long before I see improvement?
Pain relief can begin within a few days to weeks of starting. Healing of
the fissure typically takes 6 to 8 weeks of consistent twice-daily application.
If there is no improvement after 8 weeks, a review by a colorectal specialist
is needed — there are surgical options available.
Q: Can I use it during pregnancy?
Rectogesic is not generally recommended in pregnancy — there is limited
safety data. Discuss with your GP or obstetrician, who may recommend
alternative treatments such as topical anaesthetic creams, stool softeners, and
dietary measures.
Q: What other things help alongside the ointment?
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