The principal pharmacologic action of glyceryl trinitrate is mediated via the release of nitric oxide. When glyceryl trinitrate ointment is applied by the intra-anal route,the internal anal sphincter becomes relaxed.Hypertonicity of the internal but not the external anal sphincter is a predisposing factor in the formation of anal fissures.

The ointment will help to relieve the symptom of pain caused by chronic anal fissures.

Nitroglycerin 0.4% ointment should be inserted into the anal cavity with an applicator.The ointment must be inserted at least 1 cm into the anus.The dose is to be applied intra-anally every twelve hours. Treatment may be continued until the pain abates,up to a maximum of 8 weeks.

Headache and dizziness is a common side effect experienced with Nitroglycerin 0.4% ointment. A possible side effect is reduced control over bowel movements and leaking of bowel motions although this is expected to be a rare event.

Headache and dizziness is a common side effect experienced with Nitroglycerin 0.4% ointment. A possible side effect is reduced control over bowel movements and leaking of bowel motions although this is expected to be a rare event.

Overdose Effects

Accidental overdose may result in hypotension and reflex tachycardia. Because the hypotension associated with nitroglycerin overdose is the result of venodilation and arterial hypovolaemia, prudent therapy in this situation should be directed toward increasing central fluid volume. Excessive dosage may also give rise to methaemogiobinaemia. This should be treated with methylene blue infusion.

Nitroglycerin 0.4% ointment should be used with caution in patients who have severe hepatic or renal disease.It should not be used if patient suffers from severe anemia, glaucoma, hypotension, increased intracranial pressure.

Use in Special Populations

Pediatric Use: It is not recommended for use in children and adolescents below 18 years of age due to lack of data on safety and efficacy

Pregnancy & Lactation

There are no adequate data from the use of Nitroglycerin in pregnant women. Animal studies are inconclusive with respect to effects on pregnancy embryonal/foetal parturition and postnatal development. This ointment should not be used during pregnancy. It is not known whether Nitroglycerin is excreted in human milk. Due to the potential harmful effects on the breast fed child, the use of this ointment is not recommended during breast feeding.