Adverse Reaction:
Adverse Reactions include-
Inhalation- headache, throat irritation, lightheadedness and itching
Oral injection- nausea, and vomiting, substernal pain or pressure , hypotension, fainting,
and transcient complete heart block.
Contra-Indications:
Special Precautions/ Warnings-
Administration- of methacholine chloride powder for inhalation to patients with
epilepsy, cardiovascular disease accompanied by bradycardia, vagotonia, peptic ulcer
disease thyroid disease , urinary tract obstruction, or other condition that could be
adversely affected by cholinergic agent should be undertaken only if the physician
feels the benefit to the individual outweighs the potential risk.
Pregnancy - should be given to pregnant women only if it is clearly needed.
Lactation- should not be administered to a breast feeding mother since it is not known
whether methacholine chloride when inhaled is excreted in breast milk.
Children - safety and efficacy of methacholine chloride powder for inhaltion in the
inhalaton challenge have not been established below 5 years.
Patient Information:
Ref - USP PDI Vol II 17th Edition (1997)
1.Allergies-
Tell your doctor if you have ever had any unusual or allergic reaction to
methacholine, or similar medicines such as ambenonium, bethanechol,
neostigmine, and pyridostigmine. Also tell your healthcare care professional
if you are allergic to any other substances such as foods. preservatives or dyes.
2.Pregnancy-
Studies have not been done in humans or animals. However, if the test is necessary
women, who are able to bear children should be given the test within 10 days after
the beginning of the menstrual period or within 2 weeks after a pregnancy test
has shown they are not pregnant.
3. Breast-feeding-
Mothers who are taking methacholine test and and who wish to breast feed should
discuss this with their doctor.
4.Children-
Although there is no specific information comparing use of mercaptopurine in children
less than 5 years with use in other age groups, this medicine is not expected to cause
different side effects or problems than it does in adults.
5.Older adults-
There is no specific information comparing use of methacoline in the elderly with use
in other age groups
6. Other medicines-
Tell your doctor if you are using any of the following-
Anticholinergics or
Corticosteroids or
Medicines for breathing problems or hay fever or other allergies or
Smoking tobacco - these medicines or smoking tobocco may affect
the result of this test
Betablockers - these medicines may increase the reaction of methacholine test
7. Other medical problems-
Make sure you tell your doctor if you have any other medical problems
especially-
Asthma - methacholine may cause severe difficulty in breathing
Epilepsy or
Heart or blood vessel disease or
Stomach ulcer or
Thyroid disease or
Urinary tract blockage - use of methacoline may make the condition
worse.