nitroglycerin rectal ointment

Forms nitric oxide which activates the enzyme guanylate cyclase causing increased guanosine 3', 5' monophosphate (cyclic GMP). This produces vasodilation. Also reduces sphincter tone and resting intra-anal pressure.

Therapeutic effects:

Decreased pain associated with chronic anal fissure.

Pharmacokinetics ⬆ ⬇

Absorption: 50% absorbed following intra-anal applications.

Distribution: Unknown.

Metabolism/Excretion: Mostly metabolized by the liver; some extra-hepatic metabolism (red blood cells, vascular walls).

Half-Life: 2–3 min.

Time/Action Profile ⬆ ⬇

ROUTE	ONSET	PEAK	DURATION
Rect	unknown	unknown	12 hr

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity to nitrates, nitrites, nitroglycerin or any other ointment components ;
Increased intracranial pressure;
Concurrent use of sildenafil, tadalafil or vardenafil;
Severe anemia.

Use Cautiously in:

Volume depletion, hypotension, cardiomyopathy, HF, acute MI, or poor cardiac function due to other causes (may ↓ venous return, arterial resistance and BP);
Concurrent use of tissue plasminogen activator (t-PA) therapy;
OB: Use during pregnancy only if potential maternal benefit justifies potential fetal risk;
Lactation: Safety not established in breastfeeding;
Pedi: Safety and effectiveness not established in children;
Geri: ↑sensitivity to nitrates and ↑ risk of hypotension.

Adv. Reactions/Side Effects ⬆ ⬇

CV: hypotension

Hemat: methemoglobinemia (rare)

Neuro: headache, dizziness

Misc: allergic reactions (rare)

Interactions ⬆ ⬇

Drug-drug:

Concurrent use with sildenafil, tadalafil, or vardenafil↑ risk of hypotension and is contraindicated.
Concurrent use with antihypertensives, beta blockers, other nitrates, alcohol or aspirin(500–1000 mg) may ↑ risk of hypotension.
Beta blockers may ↓ reflex tachycardia from nitroglycerin.
May ↓ levels and effectiveness of t-PA.
May ↓ effectiveness of heparin.
May ↑ levels and risk of adverse cardiovascular reactions with ergotamine.

Route/Dosage ⬆ ⬇

Rect (Adults ): Apply one inch of ointment intra-anally every 12 hr for up to three weeks.

Availability ⬆ ⬇

Assessment ⬆ ⬇

Assess anal fissure and amount of pain periodically during therapy.

Implementation ⬆ ⬇

Topical Using plastic wrap, a disposable surgical glove, or finger cot, apply 1 inch of ointment intra-anally every 12 hrs. Dose is determined by laying covered finger alongside 1 inch dosing line on carton. Gently insert covered finger into anal canal no further than first finger joint and apply ointment around the side of the anal canal. If not possible due to pain, apply ointment directly to outside of anus. May continue treatment for up to 3 wks. Close tube tightly. Use within 8 wks of opening. Wash hands after application.
- Not for oral, ophthalmic, or intravaginal use.

Patient/Family Teaching ⬆ ⬇

Instruct patient to use nitroglycerin ointment as directed. Notify health care professional if anal pain does not improve.
Inform patient that nitroglycerin ointment may cause headache. Advise patient not to alter schedule due to headache; tolerance develops. May take an analgesic, such as acetaminophen to treat headache.
May cause dizziness. Caution patient to avoid driving or other activities requiring alertness until response to medication is known.
Advise patient to stop medication and notify health care professional immediately if signs of allergic reaction (swelling of face, lips, tongue, or throat, difficulty breathing) occur.
Caution patient to change positions slowly to prevent orthostatic hypotension. Avoid drinking alcohol; may increase orthostatic hypotension.
Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care professional before taking other medications, especially medications for erectile dysfunction; may increase hypotensive effects.
Rep: Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected or if breastfeeding.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇