Neophyr (Nitric Oxide)

Neophyr is an inhaled pulmonary vasodilator indicated for conditions affecting the pulmonary circulation.

• Pulmonary hypertension: lowers pulmonary arterial pressure and improves functional capacity in adult patients.
• Neonatal persistent pulmonary hypertension: enhances oxygenation and reduces the need for extracorporeal support in newborns.

• Nitric Oxide donated from Neophyr diffuses into pulmonary vascular smooth‑muscle cells, where it activates soluble guanylate cyclase. This increases cyclic GMP levels, leading to smooth‑muscle relaxation, vasodilation of the pulmonary arteries, and reduced pulmonary vascular resistance.

Neophyr may be associated with several adverse reactions.

Common Side Effects

• Cough or throat irritation
• Headache
• Dizziness or light‑headedness
• Nausea or vomiting
• Flushing or warmth sensation
• Mild hypotension

Serious or Rare Side Effects

• Methemoglobinemia
• Severe hypotension or cardiovascular collapse
• Rebound pulmonary hypertension upon abrupt discontinuation
• Bleeding complications related to platelet inhibition
• Infection from contaminated delivery system
• Pulmonary edema

When using Neophyr, clinicians should observe specific safety measures.

• Monitor blood pressure: watch for hypotensive episodes during and after inhalation.
• Assess methemoglobin levels: especially in patients with anemia or G6PD deficiency.
• Use cautiously in neonates: adjust delivery concentration and duration as per neonatal protocols.
• Avoid concurrent use with other nitric‑oxide donors: risk of additive vasodilation.
• Review anticoagulant therapy: increased bleeding risk may occur.
• Store at ambient temperature: keep cylinder upright, protect from heat and direct sunlight.

Neophyr can interact with several drug classes, requiring attention to dosing and monitoring.

Major Interactions (Avoid)

• Phosphodiesterase‑5 inhibitors (e.g., sildenafil, tadalafil): may cause profound hypotension.
• Other inhaled nitric‑oxide donors: additive vasodilatory effect leading to severe hypotension.
• Systemic vasodilators (e.g., nitroglycerin, hydralazine): risk of excessive blood pressure drop.
• Methylene blue: antagonizes nitric‑oxide activity, reducing therapeutic effect.

Moderate Interactions (Monitor Closely)

• Anticoagulants (e.g., heparin, warfarin): potential for increased bleeding.
• Inhaled anesthetics (e.g., sevoflurane, isoflurane): may enhance hypotensive response.
• Bronchodilators (e.g., albuterol): monitor for synergistic pulmonary effects.