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Nitric oxide Side Effects

For the Consumer

Applies to nitric oxide: inhalation gas

Along with its needed effects, nitric oxide may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking nitric oxide:

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

Get emergency help immediately if any of the following symptoms of overdose occur while taking nitric oxide:

Symptoms of overdose

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

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

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) 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 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.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.