Methacholine Side Effects

Medically reviewed by Drugs.com. Last updated on Feb 7, 2025.

Applies to methacholine: inhalation powder for solution, inhalation solution.

Precautions

It is very important that your doctor check you or your child's progress closely during treatment with this medicine to see if it is working properly and to check for any unwanted effects.

This medicine may cause severe bronchoconstriction and should not be used in patients with asthma or with breathing difficulties. Check with your doctor right away if you are having severe cough, difficulty breathing, noisy breathing, or tightness in the chest.

This medicine may cause mild cough, chest tightness, or trouble with breathing. This is normal and nothing to worry about.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Common side effects of methacholine

Some side effects of methacholine 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:

Serious side effects of methacholine

Along with its needed effects, methacholine 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 methacholine:

For healthcare professionals

Applies to methacholine: compounding powder, inhalation powder for reconstitution, inhalation solution.

General adverse events

When administered orally or by injection, this drug is reported to cause nausea, vomiting, substernal pain or pressure, hypotension, fainting, and transient complete heart block. Overdosage with this drug, when administered orally or by injection, can result in a syncopal reaction with cardiac arrest and loss of consciousness.^[Ref]

Dermatologic

• Rare (0.01% to 0.1%): Itching^[Ref]

Nervous system

• Rare (0.01% to 0.1%): Headache, dizziness
• Frequency not reported: Light-headedness^[Ref]

Respiratory

• Rare (0.01% to 0.1%): Throat irritation
• Frequency not reported: Bronchospasm (includes symptoms such as chest tightness, cough or wheezing)^[Ref]

See also:

Further information

Methacholine side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer