Methacholine

Provocholine, used in a methacholine challenge test, is indicated for the diagnosis of bronchial airway hyperreactivity in adults and pediatric patients five years of age and older who do not have clinically apparent asthma. Provocholine, a cholinergic agonist used in a methacholine challenge test, is indicated for the diagnosis of bronchial airway hyperreactivity in adults and pediatric patients five years of age and older who do not have clinically apparent asthma

Methacholine chloride is a cholinergic agonist. Bronchial smooth muscle contains significant parasympathetic (cholinergic) innervation. Methacholine chloride agonizes the muscarinic receptors which eventually induce bronchoconstriction.

The methacholine challenge test should be conducted in a pulmonary function laboratory or clinic, by adequately trained personnel, for safety and accuracy. Determine baseline FEV1 values to assess whether a patient is able to undergo the methacholine challenge test. See the Full Prescribing Information for the required reconstitution and dilution procedures prior to use. Recommended dosage(s) of Provocholine in the Methacholine Challenge Test is administration of increasing strengths of Provocholine solution via nebulization. Administer using either the 5-Breath Dosimeter Dosing Method or the 1-Minute Tidal Breathing Dosing Method with the doubling or quadrupling stepwise protocols. See the full Prescribing Information for administration of inhaled β-agonist after Methacholine Challenge Test.

Provocholine is contraindicated in patients with: Hypersensitivity to methacholine or other parasympathomimetic agents. Reactions have included rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. Baseline FEV 1 < 60% predicted (adults or pediatric patients) or <1.5 L (adults) hypersensitivity to methacholine chloride or other parasympathomimetic agents. Baseline FEV 1 <60% predicted (adults or pediatric patients) or <1.5 L (adults)

Boxed warning (severe bronchoconstriction warning: severe bronchoconstriction): Severe bronchoconstriction can result from Provocholine administration (including the lowest dose). The use of Provocholine is contraindicated in pediatric and adult patients with baseline FEV1 < 60% predicted or adults with FEV1 < L. . Risk of Severe Bronchoconstriction: Severe bronchoconstriction can result from Provocholine administration. Do not use Provocholine in pediatric and adult patients with baseline FEV1 <60% predicted or adults with FEV1 <1.5 L. Not recommended in patients with clinically apparent asthma or wheezing. If severe bronchoconstriction occurs, reverse with administration of rapid-acting inhaled β2-agonist.

The following adverse reactions associated with the use of Provocholine were identified in clinical studies or post marketing reports. Because some of these reactions were reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Respiratory System: Bronchospasm (includes symptoms such as chest tightness, cough or wheezing). Less Common Adverse Reactions: Headache, throat irritation, light-headedness and itching. Adverse reactions are bronchoconstriction, headache, throat irritation, light-headedness, and itching or visit www.fda.gov/medwatch

Beta-Adrenergic Blockers The use of beta-adrenergic blockers may impair reversal of Provocholine-caused bronchoconstriction. Beta-Agonists, Anticholinergics, and Theophylline Beta-agonists, anticholinergics, and theophylline inhibit the response of airways to Provocholine, therefore, hold these drugs before Provocholine use for the following duration: • Short-acting β-agonists (e.g., albuterol): 6 hours • Long-acting β-agonists (e.g., salmeterol): 36 hours • Short-acting anti-cholinergics (e.g., ipratropium): 12 hours • Long-acting anti-cholinergics (e.g., tiotropium): ≥168 hours • Oral theophylline: 12-48 hours Oral or Inhaled Corticosteroids, and Inhaled Cromoglycate Regular use of oral or inhaled corticosteroids and inhaled cromoglycate may acutely decrease bronchial responsiveness to Provocholine. However, these drugs may be continued with Provocholine use.

Store the supplied powder at 59°F to 86°F (15°C to 30°C). Store ready-to-use kits and single-dose vials between 15°C to 25°C (59°F to 77°F).