Neophyr (Nitric Oxide)

Neophyr delivers nitric oxide via inhalation to target pulmonary vascular disorders.

• Neonatal persistent pulmonary hypertension: reduces pulmonary arterial pressure and enhances oxygen exchange in newborns.
• Adult pulmonary arterial hypertension: improves hemodynamics and exercise capacity in patients with elevated pulmonary pressures.
• Acute respiratory distress syndrome: facilitates ventilation‑perfusion matching by lowering pulmonary vascular resistance.
• Post‑cardiac surgery pulmonary hypertension: supports hemodynamic stability during recovery.

• Nitric Oxide diffuses into vascular smooth‑muscle cells where it activates soluble guanylate cyclase, increasing cyclic GMP levels. Elevated cGMP leads to smooth‑muscle relaxation, vasodilation of the pulmonary circulation, and reduced vascular resistance, thereby improving oxygen delivery.

Nitric Oxide inhalation can be associated with a range of adverse reactions.

Common Side Effects

• Headache: mild to moderate discomfort often related to vasodilation.
• Dizziness or light‑headedness: due to transient blood pressure changes.
• Flushing: warm sensation on the skin.
• Hypotension: measurable drop in systemic blood pressure.
• Nausea or mild gastrointestinal upset.
• Cough or throat irritation from the gas.

Serious or Rare Side Effects

• Methemoglobinemia: elevated methemoglobin levels impairing oxygen transport.
• Severe hypotension: profound blood pressure fall requiring intervention.
• Rebound pulmonary hypertension: worsening pressure after abrupt discontinuation.
• Acute respiratory distress: unexpected worsening of breathing.
• Allergic reaction: rash, pruritus, or anaphylaxis in susceptible individuals.

When using inhaled nitric oxide, careful monitoring and specific safety measures are recommended.

• Monitor blood pressure: watch for hypotension during and after administration.
• Assess methemoglobin levels: especially in patients with G6PD deficiency or cyanosis.
• Avoid use in severe anemia: reduced oxygen‑carrying capacity may be exacerbated.
• Use cautiously with phosphodiesterase‑5 inhibitors: risk of additive vasodilation.
• Store at ambient temperature: keep cylinders in original packaging, protect from heat and direct sunlight.

Nitric oxide may interact with other agents that affect vascular tone or blood gases.

Major Interactions (Avoid)

• Concurrent potent vasodilators (e.g., nitroglycerin): can cause severe hypotension.
• Phosphodiesterase‑5 inhibitors (e.g., sildenafil): may lead to excessive pulmonary vasodilation.

Moderate Interactions (Monitor Closely)

• Inhaled anesthetics (e.g., sevoflurane): may potentiate blood pressure lowering.
• Beta‑blockers: can mask compensatory tachycardia.
• Anticoagulants: increased bleeding risk due to vasodilatory effects on pulmonary vessels.