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INOmax Side Effects

Generic Name: nitric oxide

Note: This page contains information about the side effects of nitric oxide. Some of the dosage forms included on this document may not apply to the brand name INOmax.

For the Consumer

Applies to nitric oxide: inhalation gas

In addition to its needed effects, some unwanted effects may be caused by nitric oxide (the active ingredient contained in INOmax). In the event that any of these side effects do occur, they may require medical attention.

If any of the following side effects occur while taking nitric oxide, check with your doctor or nurse immediately:

More common:
  • Blurred vision
  • confusion
  • dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  • sweating
  • unusual tiredness or weakness
Incidence not known:
  • Bluish lips or skin
  • chest discomfort
  • difficult or labored breathing
  • dizziness
  • tightness in the chest
  • trouble breathing

If any of the following symptoms of overdose occur while taking nitric oxide, get emergency help immediately:

Symptoms of overdose:
  • Bluish-colored lips, fingernails, or palms
  • dark urine
  • fever
  • headache
  • pale skin
  • rapid heart rate
  • sore throat
  • unusual bleeding or bruising

Minor Side Effects

Some of the side effects that can occur with nitric oxide may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

Incidence not known:
  • Dry throat

For Healthcare Professionals

Applies to nitric oxide: inhalation gas


Hematologic side effects including methemoglobinemia (which increases with the dose of nitric oxide (the active ingredient contained in INOmax) have been reported. Elevated NO2 levels have also been reported.[Ref]

In one study 35% of neonates treated with nitrous oxide 80 ppm had methemoglobin levels exceeding 7%. Following discontinuation or reduction of nitric oxide the methemoglobin levels returned to baseline over a period of hours.[Ref]


Cardiovascular side effects including hypotension (13%) have been reported.[Ref]


Other side effects including withdrawal (12%), sepsis (7%), infection (6%), and cellulitis (5%) have been reported. Accidental exposure of hospital staff to nitric oxide (the active ingredient contained in INOmax) has been associated with chest discomfort, dizziness, dry throat, dyspnea, and headache.[Ref]


Respiratory side effects including atelectasis (9%) and stridor (5%) have been reported.[Ref]


Renal side effects including hematuria (8%) have been reported.[Ref]


Metabolic side effects including hyperglycemia (8%) have been reported.[Ref]


1. "Product Information. INOmax (nitric oxide)." INO Therapeutics Inc, Clinton, NJ.

Not all side effects for INOmax may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

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