Methacholine Chloride
Methacholine Chloride is a synthetic cholinergic agent that acts as a muscarinic receptor agonist. It is used diagnostically to assess bronchial hyperreactivity, primarily in patients with suspected asthma who have normal baseline lung function tests.
A diagnostic agent used to diagnose asthma and bronchial hyperreactivity by provoking bronchoconstriction in a controlled clinical setting.
Key facts at a glance
- RxNorm
- 40165
- Generic
- Methacholine Chloride
- Class
- pin-variant
- Brands
- —
- Availability
- rx
- Lactation
- unknown
- Routes
- —
- Forms
- —
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Methacholine Chloride is primarily used for bronchial provocation testing to diagnose asthma and assess bronchial hyperreactivity in patients presenting with cough, wheezing, or dyspnea when initial spirometry results are normal.
As a muscarinic receptor agonist, Methacholine Chloride stimulates muscarinic receptors in bronchial smooth muscle, causing bronchoconstriction. Individuals with asthma exhibit heightened bronchial sensitivity, experiencing significant airway narrowing at lower doses compared to non-asthmatic individuals.
This medication should only be administered in controlled clinical settings with emergency equipment readily available due to the risk of severe bronchoconstriction. It is contraindicated in patients with active asthma symptoms, recent myocardial infarction, severe hypertension, or seizure disorders. Testing must be conducted by trained healthcare professionals capable of managing adverse reactions.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 28, 2026. · Read our editorial policy