Methacholine (Inhalation)

Methacholine (Inhalation) is used to help your doctor diagnose bronchial airway hyperreactivity or asthma. This medicine works by narrowing your bronchial airways. The level of narrowing will be measured by a device called a spirometer. This test is also known as the methacholine challenge test.

This medicine is to be given only under the supervision of your doctor.

It is very important that your doctor checks 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.

In deciding to use a diagnostic test, you and your doctor need to consider the risks of the test against the benefits it may provide. Other factors can also affect the test results. For this test, keep the following in mind:

Allergies

Inform your doctor if you have ever had any unusual or allergic reactions to this medicine or any other medicines. Also, let your healthcare professional know if you have other allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

There have not been appropriate studies on how methacholine inhalation affects children younger than 5 years old. Safety and effectiveness have not been established for this age group.

Geriatric

There is no information available about how methacholine inhalation affects elderly patients.

Breast Feeding

There are no adequate studies in women to determine the risk to infants when using this medication while breastfeeding. Consider the potential benefits and risks before taking this medication while breastfeeding.

Interactions with Medicines

Some medicines should not be used together at all, while in other cases, two different medicines may be used together even if there might be an interaction. In these situations, your doctor may need to adjust the dose, or other precautions may be required. It is especially important for your healthcare professional to know if you are taking any of the medicines listed below when receiving this diagnostic test. The following interactions have been chosen because of their potential significance and may not include all possible interactions.

Receiving this diagnostic test with any of the following medicines is usually not recommended, but may be necessary in some instances. If both medicines are prescribed together, your doctor may adjust the dose or frequency for one or both medicines.

• Aclidinium
• Albuterol
• Amantadine
• Amitriptyline
• Amoxapine
• Arformoterol
• Atropine
• Bambuterol
• Belladonna
• Benztropine
• Biperiden
• Brompheniramine
• Carbinoxamine
• Carisoprodol
• Chlorpheniramine
• Chlorpromazine
• Clemastine
• Clenbuterol
• Clidinium
• Clomipramine
• Clozapine
• Colterol
• Cyclobenzaprine
• Cyclopentolate
• Cyproheptadine
• Darifenacin
• Desipramine
• Dicyclomine
• Dimenhydrinate
• Diphenhydramine
• Doxepin
• Fenoterol
• Fesoterodine
• Flavoxate
• Fluphenazine
• Formoterol
• Glycopyrrolate
• Glycopyrronium Tosylate
• Hexoprenaline
• Homatropine
• Hydroxyzine
• Hyoscyamine
• Imipramine
• Indacaterol
• Ipratropium
• Isoetharine
• Levalbuterol
• Loxapine
• Meclizine
• Mepenzolate
• Metaproterenol
• Nortriptyline
• Olanzapine
• Olodaterol
• Orphenadrine
• Oxitropium Bromide
• Oxybutynin
• Paroxetine
• Perphenazine
• Pimozide
• Pipenzolate Bromide
• Pirbuterol
• Pirenzepine
• Procaterol
• Prochlorperazine
• Procyclidine
• Promethazine
• Propantheline
• Propiverine
• Protriptyline
• Reproterol
• Ritodrine
• Salmeterol
• Scopolamine
• Solifenacin
• Stramonium
• Terbutaline
• Terodiline
• Theophylline
• Thioridazine
• Thiothixene
• Tiotropium
• Tizanidine
• Tolterodine
• Tretoquinol
• Trifluoperazine
• Trihexyphenidyl
• Trimipramine
• Tropicamide
• Trospium
• Tulobuterol
• Umeclidinium
• Vilanterol

Interactions with Food/Tobacco/Alcohol

Some medicines should not be used during meals or shortly before or after eating certain foods due to possible interactions. Using alcohol or tobacco with certain medicines may also lead to interactions. Discuss with your healthcare professional about using your medicine with food, alcohol, or tobacco.

Other Medical Problems

Other medical issues may affect the use of this diagnostic test. Be sure to inform your doctor about any other medical conditions, especially:

• Allergic rhinitis without asthma symptoms or
• Infection (e.g., upper respiratory infection, influenza) or
• Chronic lung disease (e.g., COPD, tuberculosis, sarcoidosis, or cystic fibrosis)—Using this test in patients with these conditions may sometimes lead to a false-positive result.

• Aortic aneurysm (bulge in the main artery of the heart) or
• History of heart attack or
• Uncontrolled hypertension (high blood pressure) or
• History of stroke—Use with caution. It is not recommended for patients with these conditions.

• Epilepsy or
• Peptic ulcer disease or
• Thyroid disease or
• Urinary tract blockage or
• Vagotonia (excessive activity of the vagus nerve)—Use with caution. There may be a higher risk for side effects. Your doctor should only test this medicine in patients with these conditions if the benefits outweigh the risks.

Along with its needed effects, a medicine may cause some unwanted effects. While 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:

Incidence not known

• Cough
• difficulty breathing
• noisy breathing
• tightness in the chest

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Your health care professional may also 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:

Less common

• Headache
• itching
• lightheadedness
• throat irritation

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

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

In the U.S.

• Provocholine

Available Dosage Forms:

• Solution
• Powder for Solution

Therapeutic Class: Diagnostic Agent, Bronchial

Pharmacologic Class: Cholinergic System

A doctor or other health professional will give you this medicine in the hospital. It is given through oral inhalation using a dosimeter. Your doctor will also use a device, called a spirometer, to check for your lung function.