Rectogesic® (rectal glyceryl trinitrate)

Rectogesic® is a rectal ointment containing the active ingredient glyceryl trinitrate (GTN, also known as nitroglycerin) at a concentration of 0.4%. It is an approved medication that specifically relaxes the internal anal sphincter and is used primarily to treat chronic anal fissures.

Unlike the other hemorrhoid preparations, Rectogesic® contains neither a corticosteroid nor a local anesthetic. Instead, glyceryl trinitrate releases nitric oxide (NO), which relaxes the smooth muscle of the sphincter and improves local blood flow.

This relieves the pain of chronic anal fissures. Rectogesic® is approved for pain relief, not for healing the fissure.

Rectogesic® works by releasing nitric oxide (NO):

Mechanism of action:

• Glyceryl trinitrate is converted locally into nitric oxide (NO)
• NO activates guanylate cyclase in smooth muscle
• Increase in cGMP levels
• Relaxation of the smooth muscle of the internal anal sphincter

Therapeutic effects:

• Reduction of resting pressure in the anal canal (by 20–30%)
• Relaxation of the internal anal sphincter
• Improved anodermal blood flow
• Pain relief through reduced sphincter spasm

Onset of action:

• Sphincter relaxation: within 15–30 minutes

Rectogesic® is suitable for:

• Adults with a chronic anal fissure
• Painful sphincter spasm (cramping of the sphincter muscle)

Especially recommended for:

• Chronic anal fissures (> 6 weeks)
• When conservative measures (sitz baths, stool regulation) are not sufficient
• Painful symptoms associated with bowel movements due to sphincter spasm

Not suitable:

• Children and adolescents under 18 years of age
• Concomitant use of PDE-5 inhibitors (sildenafil, tadalafil)
• Severe hypotension (low blood pressure)
• Known hypersensitivity to nitrates

Dosage:

• 375 mg ointment (equivalent to approx. 1.5 mg glyceryl trinitrate) rectally every 12 hours
• 2 × daily (morning and evening)
• 375 mg corresponds to a strip of ointment approx. 2.5 cm long

Dosing aid:

• There is a 2.5 cm guide line on the outer carton: hold your finger next to it and squeeze out the ointment until the strip is as long as the line
• A strip of ointment from the fingertip to the middle of the first finger segment = approx. 375 mg

Duration of use:

• Maximum 8 weeks
• Treatment can be continued until the pain subsides
• If there is no response: discuss surgical options

Available strength:

• 0.4% glyceryl trinitrate rectal ointment (30 g tube)

Application:

• Squeeze a strip of ointment approx. 2.5 cm long onto your finger
• Gently insert your finger into the anal canal up to the first finger joint
• This applies the ointment inside the anal canal (intra-anally)
• Wash your hands thoroughly afterward (risk of headache!)

Important notes:

• WASH YOUR HANDS THOROUGHLY after application (nitroglycerin is absorbed through the skin)
• Use disposable gloves if available
• If gloves are not possible: wrap your finger in plastic wrap
• Apply 2 × daily, 12 hours apart
• Headaches are common – they usually subside after a few days

Application tip: It is best to apply the ointment in the morning and evening after a bowel movement and gentle cleansing. Do not rub – just dab gently.

Rectogesic® must not be used in cases of:

• Hypersensitivity to glyceryl trinitrate or other nitrates
• Concomitant use of PDE-5 inhibitors (sildenafil, tadalafil, vardenafil) – life-threatening drop in blood pressure!
• Concomitant use of riociguat
• Severe anemia
• Increased intracranial pressure
• Hypovolemia (volume deficiency)
• Severe hypotension (low blood pressure)
• Constrictive pericarditis
• Migraine or frequent headaches
• Orthostatic hypotension (drop in blood pressure when standing up)

Caution in cases of:

• Cardiovascular diseases
• Concomitant use of blood-pressure-lowering medications

Pregnancy and breastfeeding: Insufficient data. Only when strictly indicated, after careful consideration by a physician.

Very common (> 10%):

• Headaches (most common side effect, in over 50% of patients!)

→ Usually subside after a few days of use → If needed: paracetamol for the headaches

Common (1–10%):

• Dizziness
• Nausea

Uncommon (0.1–1%):

• Anal burning and itching (anal pruritus)
• Rectal bleeding
• Tachycardia (racing heart)

Frequency not known:

• Drop in blood pressure, including when standing up (hypotension, orthostatic hypotension)
• Light-headedness, fainting (syncope)
• Hypersensitivity reactions
• Irritation, rash or pain at the application site
• Feeling of warmth (flushing)

Note: Headaches occur in more than half of patients because nitroglycerin also dilates the blood vessels in the head. They are the most common reason for stopping treatment. In most patients, the headaches subside after 3–7 days as the body gets used to the effect (development of tolerance).

Contraindicated with:

• PDE-5 inhibitors (sildenafil, tadalafil, vardenafil) → life-threatening drop in blood pressure!
• Riociguat → increased lowering of blood pressure

Caution with:

• Other antihypertensives (ACE inhibitors, sartans, beta-blockers, calcium channel blockers) → increased drop in blood pressure
• Alcohol → increased lowering of blood pressure
• Tricyclic antidepressants → increased hypotension
• Heparin → reduced heparin effect with nitrates
• Ergotamine → increased effect of ergotamine

Important: Although rectal use results in lower systemic absorption than oral use, interactions with blood-pressure-lowering medications can occur. The contraindication with PDE-5 inhibitors is absolute – even with rectal use.