Home Drug Guide Nitric Oxide

Drug Guide

Generic Name

Nitric Oxide

Brand Names Inomax, Genosyl, Ulspira, Noxivent

Classification

Therapeutic: Vasodilator, Pulmonary hypertension agent

Pharmacological: Vasodilator, Nitric Oxide donor

FDA Approved Indications

Treatment of term and near-term neonates with hypoxic respiratory failure associated with pulmonary hypertension

Mechanism of Action

Nitric oxide is a potent vasodilator that relaxes smooth muscle in blood vessel walls by activating soluble guanylate cyclase, leading to increased cyclic GMP levels, resulting in vasodilation, especially in pulmonary vasculature.

Dosage and Administration

Adult: Initially, 20 ppm via inhalation, titrated based on response and tolerance. Duration varies, typically 24-48 hours,

Pediatric: Dosing varies with weight and response; often starts at 20 ppm, titrated as needed. Administer via calibrated inhalation system.

Geriatric: No specific adjustments required, but monitor closely due to comorbidities.

Renal Impairment: No specific dose adjustment needed.

Hepatic Impairment: No specific dose adjustment needed.

Pharmacokinetics

Absorption: Rapid absorption via inhalation; effects observed within minutes.

Distribution: Limited to pulmonary circulation; minimal systemic absorption at therapeutic doses.

Metabolism: Rapidly inactivated in blood and tissues, mainly by binding to hemoglobin to form methemoglobin.

Excretion: Metabolized to nitrates and nitrites, excreted via urine.

Half Life: Milliseconds in blood; effects are reversible within minutes after discontinuation.

Contraindications

Known intolerance or hypersensitivity to nitric oxide.
Recent exposure to high concentrations of nitric oxide or nitrogen dioxide.

Precautions

Use with caution in patients with right-to-left shunting, anemia, or worsening hypoxemia.
Close monitoring of methemoglobin levels is essential.

Adverse Reactions - Common

Hypotension (Frequent)
Methemoglobinemia (Less frequent (monitor levels))

Adverse Reactions - Serious

Severe hypotension (Rare)
Pulmonary hypertension rebound (Rare)
Oxygen toxicity with prolonged use (Rare)

Drug-Drug Interactions

None specifically documented, but careful monitoring needed when used with other vasodilators or hypotensive agents.

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor blood pressure, oxygenation, and methemoglobin levels. Assess response to therapy.

Diagnoses:

Impaired gas exchange
Risk for hypotension

Implementation: Ensure proper setup of inhalation delivery system, titrate dose carefully, and monitor patient response.

Evaluation: Effectiveness assessed by improved oxygenation and stable blood pressure.

Patient/Family Teaching

Explain purpose and process of inhaled nitric oxide therapy.
Notify healthcare provider if symptoms worsen or if side effects occur.
Emphasize the importance of close monitoring during therapy.

Special Considerations

Black Box Warnings:

Potential for pulmonary toxicity if used continuously beyond recommended duration.
Rebound pulmonary hypertension if discontinued abruptly.

Genetic Factors: None specific.

Lab Test Interference: May cause falsely elevated levels of nitrates/nitrites in blood tests.

Overdose Management

Signs/Symptoms: Hypotension, methemoglobinemia, severe hypoxemia.

Treatment: Discontinue nitric oxide, provide supportive care, administer oxygen, and treat methemoglobinemia with methylene blue if indicated.

Storage and Handling

Storage: Store in a cool, dry place, protected from light.

Stability: Stable when stored properly; discard opened vials after 24 hours.