Why is methacholine used?
Methacholine inhalation is used to help your doctor diagnose bronchial airway hyperreactivity or asthma. This medicine works by narrowing your bronchial airways. The degree of narrowing will be measured by a device called a spirometer. This test is also called the methacholine challenge test.
What is methacholine made of?
Methacholine is a quaternary ammonium ion in which the nitrogen is substituted with three methyl groups and a 2-acetoxypropyl group. Parasympathomimetic bronchoconstrictor drug used in clinical diagnosis.
How is methacholine administered?
Methacholine is administered sequentially in increasing concentrations ranging from 0.016 to 16 mg/m, prepared in two to four-fold dilutions. The tester should perform spirometry before establishing a baseline. Then methacholine is given via nebulization starting with the lowest (most diluted) concentration.
What does methacholine do to your lungs?
Methacholine is an inhaled drug that causes mild narrowing of the airways in the lungs, like asthma. A methacholine challenge test can be done in your doctor’s office or in a pulmonary function lab.
What kind of drug is methacholine?
Methacholine is a non-specific cholinergic agonist (parasympathomimetic) that acts through muscarinic receptors in the lungs to induce bronchoconstriction, which is more significant in patients with asthma than those without.
Does methacholine have side effects?
Headache, sore throat, lightheadedness, nausea, vomiting, or dizziness may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects.
What are the side effects of methacholine?
SIDE EFFECTS: Headache, sore throat, lightheadedness, nausea, vomiting, or dizziness may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.
What does methacholine do to the lungs?
What type of drug is methacholine?
Can methacholine be used to treat asthma?
It is not used to treat asthma. It is given by breathing in liquid only. Very bad breathing problems can happen with methacholine. If you are having breathing problems like wheezing or asthma signs or have low lung function tests, talk with your doctor. You will be closely watched by your doctor.
What happens if you test positive for methacholine?
If you begin to experience discomfort, such as wheezing and increased shortness of breath, or the breathing test demonstrates significant narrowing of the airways, your doctor will end the test. The challenge test is considered positive if methacholine causes a 20 percent or greater decrease in your breathing ability when compared to your baseline.
What are the indications for methacholine challenge testing?
A. Indications. Methacholine challenge testing is one method of assessing airway responsiveness. Airway hyperresponsiveness is one of the features that may contribute to a diagnosis of asthma. It may vary over time, often increasing during exacerbations and decreasing during treatment with antiinflammatory medications.
Methacholine is a synthetic derivative of the neurotransmitter acetylcholine, a substance that occurs naturally in the body. Methacholine is metabolized more slowly by cholinesterase; its effects can be blocked or lessened by atropine or similar anticholinergic agents.