Skip to Content

Nitric oxide Side Effects

For the Consumer

Applies to nitric oxide: inhalation gas

As well as its needed effects, nitric oxide may cause unwanted side effects that 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 nitric oxide side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned 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.

It is possible that some side effects of nitric oxide may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.