Drug Guide

Generic Name

Nitroglycerin

Brand Names Tridil, Nitrostat, Nitro-bid, Nitronal, Nitro IV, Nitrolingual, Nitrolingual Pumpspray, Nitrol, Nitroglycerin In Dextrose 5%, Transderm-nitro, Nitro-dur, Rectiv, Nitromist, Minitran, Gonitro

Classification

Therapeutic: Antianginal agent

Pharmacological: Nitrate (vasodilator)

FDA Approved Indications

Angina pectoris due to coronary artery disease
Acute coronary syndrome (with other therapies)

Mechanism of Action

Nitroglycerin is converted to nitric oxide in the body, which activates guanylate cyclase, increasing cyclic GMP levels, leading to smooth muscle relaxation and vasodilation, predominantly of veins, reducing myocardial oxygen demand.

Dosage and Administration

Adult: Doses vary by formulation; sublingual tablets: 0.3-0.6 mg every 5 minutes as needed, up to 3 doses in 15 minutes. Transdermal patches: 0.2-0.8 mg/hr applied once daily for 12-14 hours.

Pediatric: Use with caution; consult specific pediatric guidelines.

Geriatric: Start at lower doses; monitor closely.

Renal Impairment: Adjustments generally not necessary, but caution advised.

Hepatic Impairment: Data limited; use cautiously.

Pharmacokinetics

Absorption: Rapid after sublingual and IV administration.

Distribution: Wide distribution; crosses placenta.

Metabolism: Liver metabolism via conjugation and reduction.

Excretion: Renal pathways; metabolites active.

Half Life: 1-4 minutes for IV; longer for transdermal formulations.

Contraindications

Hypersensitivity to nitroglycerin or other nitrates
Use with phosphodiesterase inhibitors (e.g., sildenafil)

Precautions

Severe anemia
Head trauma or increased intracranial pressure
Use with caution in hypotension or hypovolemia

Adverse Reactions - Common

Headache (Very common)
Dizziness or lightheadedness (Common)
Flushing (Common)
Nausea (Uncommon)

Adverse Reactions - Serious

Hypotension (Less common)
Reflex tachycardia (Less common)
Methemoglobinemia (rare) (Rare)

Drug-Drug Interactions

Erectile dysfunction drugs (e.g., sildenafil) - severe hypotension risk

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor blood pressure, heart rate, pain relief, and adverse effects.

Diagnoses:

Ineffective tissue perfusion related to vasodilation

Implementation: Administer as prescribed; ensure correct formulation and route; avoid abrupt discontinuation.

Evaluation: Assess relief of anginal pain and monitor for hypotension.

Patient/Family Teaching

Instruct on proper use of sublingual tablets and transdermal patches.
Avoid sudden position changes to prevent dizziness.
Report severe headaches or signs of hypotension.
Use as directed and do not exceed prescribed doses.

Special Considerations

Black Box Warnings:

Potential for precipitating severe hypotension and bradycardia.
Use with caution in head trauma or increased intracranial pressure.

Genetic Factors: Limited data.

Lab Test Interference: None noted.

Overdose Management

Signs/Symptoms: Severe hypotension, tachyarrhythmias, headache, dizziness.

Treatment: Discontinue nitroglycerin, provide supportive care, and administer IV fluids or vasopressors if needed.

Storage and Handling

Storage: Store in a tightly closed container away from heat and light.

Stability: Stable under recommended conditions; check specific formulation expiry.