nitroglycerin

Absorption: Well absorbed after oral, buccal, and sublingual administration. Also absorbed through skin. Orally administered nitroglycerin is rapidly metabolized, leading to ↓ bioavailability.

Distribution: Unknown.

Metabolism/Excretion: Undergoes rapid and almost complete metabolism by the liver; also metabolized by enzymes in bloodstream.

Half-Life: 1–4 min.

Time/Action Profile ⬆ ⬇

(cardiovascular effects)

ROUTE	ONSET	PEAK	DURATION
SL/Translingual	1–3 min	unknown	30–60 min
PO-ER	40–60 min	unknown	8–12 hr
Oint	20–60 min	unknown	4–8 hr
Patch	40–60 min	unknown	8–24 hr
IV	immediate	unknown	several min

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
↑intracranial pressure;
Severe anemia;
Pericardial tamponade;
Constrictive pericarditis;
Uncorrected hypovolemia;
Alcohol intolerance (large IV doses only);
Acute circulatory failure/shock;
Concurrent use of PDE-5 inhibitor (avanafil, sildenafil, tadalafil, vardenafil) or riociguat.

Use Cautiously in:

Head trauma or cerebral hemorrhage;
Glaucoma;
Hypertrophic cardiomyopathy;
Severe liver impairment;
Malabsorption or hypermotility (PO);
Cardioversion (remove transdermal patch before procedure);
OB: May compromise maternal/fetal circulation;
Lactation: Safety not established in breastfeeding;
Pedi: Safety and effectiveness not established in children.

Adv. Reactions/Side Effects ⬆ ⬇

CV: hypotension, tachycardia, syncope

Derm: contact dermatitis (transdermal), flushing

EENT: blurred vision

GI: abdominal pain, nausea, vomiting

Neuro: dizziness, headache, apprehension, restlessness, weakness.

Misc: alcohol intoxication (large IV doses only), tolerance

Interactions ⬆ ⬇

Drug-drug:

Concurrent use of avanafil, sildenafil, tadalafil, or vardenafil may result in severe hypotension (do not use within 24 hr of isosorbide dinitrate or mononitrate); concurrent use contraindicated.
Concurrent use of riociguat may result in severe hypotension; concurrent use contraindicated.
Additive hypotension with antihypertensives, acute ingestion of alcohol, beta blockers, calcium channel blockers, haloperidol, or phenothiazines.
Agents having anticholinergic properties (tricyclic antidepressants, antihistamines, phenothiazines) may ↓ absorption of translingual or sublingual nitroglycerin.

Route/Dosage ⬆ ⬇

(Adults ): Tablets: 0.3–0.6 mg; may repeat every 5 min for 2 additional doses for acute attack; may also be used prophylactically 5–10 min before activities that may precipitate an acute attack.
Translingual Spray
(Adults ): 1–2 sprays; may be repeated every 5 min for 2 additional doses for acute attack; may also be used prophylactically 5–10 min before activities that may precipitate an acute attack.
PO (Adults ): 2.5–9 mg every 8–12 hr.
IV (Adults ): 5 mcg/min; ↑ by 5 mcg/min every 3–5 min to 20 mcg/min; if no response, ↑ by 10–20 mcg/min every 3–5 min (dosing determined by hemodynamic parameters; max: 200 mcg/min).
Transdermal (Adults ): Ointment: 1–2 in. every 6–8 hr. Transdermal patch: 0.2–0.4 mg/hr initially; may titrate up to 0.4–0.8 mg/hr. Patch should be worn 12–14 hr/day and then taken off for 10–12 hr/day.

Availability ⬆ ⬇

(Generic available)

Extended-release capsules: 2.5 mg; 6.5 mg; 9 mg
Sublingual tablets: 0.3 mg; 0.4 mg; 0.6 mg
Translingual spray: 0.4 mg/spray in 4.9-g bottle (60 doses) or 14.6-g bottle (200 doses) (Nitrolingual); 0.4 mg/spray in 8.5-g bottle (230 doses) (Nitromist)
Transdermal patch: 0.1 mg/hr; 0.2 mg/hr; 0.3 mg/hr; 0.4 mg/hr; 0.6 mg/hr; 0.8 mg/hr
Transdermal ointment: 2%
Solution for injection: 5 mg/mL
Premixed infusion: 25 mg/250 mL D5W; 50 mg/250 mL D5W; 100 mg/250 mL D5W

Assessment ⬆ ⬇

Assess location, duration, intensity, and precipitating factors of patient’s anginal pain.
Monitor BP and pulse before and after administration. Patients receiving IV nitroglycerin require continuous ECG and BP monitoring. Additional hemodynamic parameters may be monitored.

Lab Test Considerations:

May cause ↑ urine catecholamine and urine vanillylmandelic acid concentrations.
- Excessive doses may cause ↑ methemoglobin concentrations.
- May cause falsely ↑ serum cholesterol levels.

Implementation ⬆ ⬇

PO: Administer dose 1 hr before or 2 hr after meals with a full glass of water for faster absorption. DNC: Sustained-release preparations should be swallowed whole; do not break, crush, or chew.
Tablet should be held under tongue until dissolved. Avoid eating, drinking, or smoking until tablet is dissolved.
Translingual spray: Spray Nitrolingual under tongue. Spray Nitromist on or under tongue.
Rotate sites of topical application to prevent skin irritation. Remove patch or ointment from previous site before application.
- Doses may be increased to the highest dose that does not cause symptomatic hypotension.
- Apply ointment by using dose-measuring application papers supplied with ointment. Squeeze ointment onto measuring scale printed on paper. Use paper to spread ointment onto nonhairy area of skin (chest, abdomen, thighs; avoid distal extremities) in a thin, even layer, covering a 2–3-in. area. Do not allow ointment to come in contact with hands. Do not massage or rub in ointment; this will increase absorption and interfere with sustained action. Apply occlusive dressing if ordered.
- Transdermal patches may be applied to any hairless site (avoid distal extremities or areas with cuts or calluses). Apply firm pressure over patch to ensure contact with skin, especially around edges. Apply a new dose unit if the first one becomes loose or falls off. Units are waterproof and not affected by showering or bathing. Do not cut or trim system to adjust dosage. Do not alternate between brands of transdermal products; dose may not be equivalent. Remove patches before MRI, cardioversion or defibrillation to prevent patient burns. Patch may be worn for 12–14 hr and removed for 10–12 hr at night to prevent development of tolerance.

IV Administration:

IV: Doses must be diluted and administered as an infusion. Standard infusion sets made of polyvinyl chloride (PVC) plastic may absorb up to 80% of the nitroglycerin in solution. Use glass bottles only and special tubing provided by manufacturer.
Diluent: Vials must be diluted in D5W or 0.9% NaCl. Premixed infusions already diluted in D5W and are ready to be administered (no further dilution needed). Admixed solutions stable for 48 hr at room temperature or 7 days if refrigerated. Stability of premixed solutions based on manufacturer's expiration date.Concentration: Should not exceed 400 mcg/mL.
Rate: See Route/Dosage section. Administer via infusion pump to ensure accurate rate. Titrate rate according to patient response.

Patient/Family Teaching ⬆ ⬇

Instruct patient to take medication as directed, even if feeling better. Take missed doses as soon as remembered unless next dose is scheduled within 2 hr (6 hr with extended-release preparations). Do not double doses. Do not discontinue abruptly; gradual dose reduction may be necessary to prevent rebound angina.
- Caution patient to change positions slowly to minimize orthostatic hypotension. First dose should be taken while in a sitting or reclining position, especially in geriatric patients.
- Advise patient to avoid concurrent use of alcohol with this medication. Patient should also consult health care professional before taking OTC medications while taking nitroglycerin.
- Inform patient that headache is a common side effect that should decrease with continuing therapy. Aspirin or acetaminophen may be ordered to treat headache. Notify health care professional if headache is persistent or severe.
- Advise patient to notify health care professional if dry mouth or blurred vision occurs.
Rep: Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected or if breastfeeding.
Acute Anginal Attacks: Advise patient to sit down and use medication at first sign of attack. Relief usually occurs within 5 min. Dose may be repeated if pain is not relieved in 5–10 min. Call health care professional or go to nearest emergency room if anginal pain is not relieved by 3 tablets in 15 min.
Inform patient that tablets should be kept in original glass container or in specially made metal containers, with cotton removed to prevent absorption. Tablets lose potency in containers made of plastic or cardboard or when mixed with other capsules or tablets. Exposure to air, heat, and moisture also causes loss of potency. Instruct patient not to open bottle frequently, handle tablets, or keep bottle of tablets next to body (i.e., shirt pocket) or in automobile glove compartment. Advise patient that tablets should be replaced 6 mo after opening to maintain potency.
Lingual Spray: Instruct patient to lift tongue and spray dose under tongue (Nitrolingual, NitroMist) or on tongue (NitroMist).

Evaluation/Desired Outcomes ⬆ ⬇

Decrease in frequency and severity of anginal attacks.
- Increase in activity tolerance. During long-term therapy, tolerance may be minimized by intermittent administration in 12–14 hr or 10–12 hr off intervals.
Controlled hypotension during surgical procedures.
Treatment of HF associated with acute MI.

US Brand Names ⬆ ⬇

nitroglycerin extended-release capsules: Nitro-Time,

nitroglycerin intravenous: ~~Nitro-Bid IV,~~ ~~Tridil,~~

nitroglycerin sublingual tablets: Nitrostat,

nitroglycerin transdermal ointment: Nitro-Bid,

nitroglycerin transdermal patch: Nitro-Dur,

nitroglycerin translingual spray: Nitrolingual, Nitromist

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇