Methacholine (By breathing)


Methacholine (meth-a-KOE-leen)

Used as part of a medical test of the lungs.

Brand Name(s)


When This Medicine Should Not Be Used

How to Use This Medicine

Liquid Under Pressure

  • A nurse or other trained health professional will give you this medicine.

Drugs and Foods to Avoid

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Certain medicines may interfere with your test. Your doctor may need to adjust the dose of some of your medicine before your test, or you may need to stop taking certain medicines for a short time before your test. Follow your doctor's instructions.

Warnings While Using This Medicine

  • Make sure your doctor knows if you are pregnant or breastfeeding. Your test may need to be scheduled within ten days of the start of your last period, or within ten days of your last negative pregnancy test.
  • Make sure your doctor knows if you have epilepsy, heart disease or heart rhythm problems, circulation problems, or a history of nerve problems or fainting. Tell your doctor if you have a history of ulcers, thyroid problems, constipation, or a blocked urinary tract. Make sure your doctor knows if you are taking medicine to treat myasthenia gravis. Tell your doctor about any other medical problems you may have, or that you have had in the past.

Possible Side Effects While Using This Medicine

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Lightheadedness.
  • Wheezing.

If you notice these less serious side effects, talk with your doctor:

  • Headache or throat irritation.

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Version Info

  • Last reviewed on 10/4/2017

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