Question

Which one of the following drugs that is not absorbed orally, is not a bronchodilator, does not have any direct effects on smooth muscles yet is effective in antigen-induced, exercise- induced and irritant-induced asthma though not all asthmatics respond to it positively?

• A. Salbutamol
• B. Montelukast
• C. Sodium cromoglycate
• D. Terbutaline

Answer 1

The Correct Option is C

This question tests the understanding of the different properties and mechanisms of action of drugs used in the management of asthma.

Let's analyze each option to determine the correct answer:

1. Salbutamol: Salbutamol is a bronchodilator. It is a beta-2 adrenergic agonist that directly acts on smooth muscles to cause bronchodilation. Therefore, it is not the correct answer, as it does not match the criteria of having no direct effects on smooth muscles.
2. Montelukast: Montelukast is an oral leukotriene receptor antagonist that helps control asthma symptoms by blocking leukotriene pathways rather than directly affecting smooth muscle contraction. However, it is orally absorbed and does have a role in asthma management, but it doesn't match all the conditions in the question.
3. Sodium Cromoglycate: Sodium cromoglycate is not absorbed orally and thus is administered through inhalation. It is a mast cell stabilizer; it works by preventing the release of histamine and other inflammatory mediators from mast cells. It does not act directly on smooth muscle. This makes it suitable for managing antigen-induced, exercise-induced, and irritant-induced asthma. However, not all asthmatic patients respond to it positively. These characteristics make it the correct answer.
4. Terbutaline: Terbutaline, similar to salbutamol, is a beta-2 adrenergic agonist. It is a bronchodilator and does directly relax smooth muscles, which disqualifies it as the correct option.

Considering all the options and their properties, Sodium Cromoglycate is identified as the correct answer because it matches all the specified criteria:

• Not absorbed orally
• Not a bronchodilator
• No direct effects on smooth muscles
• Effective in antigen-induced, exercise-induced, and irritant-induced asthma, though not universally effective for all asthmatics