A- DISODIUM CROMOGLYCATE
They inhibits or prevents bronchospasm induced by various stimuli including antigens, exercise, cold or dry air. Also, its chronic use may reduce the overall level of bronchial hyperreactivity.
Mechanism of action:
stabilizes mast cells so preventing release of mediators induced by antigens & nonspecific stimuli.
This occurs by inhibiting Ca++ influx across mast cell membrane. It also suppresses inflammatory cell influx and chemotactic activity as well as antigen induced reactivity.
Therapeutic Uses:
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It is used as a prophylactic treatment in case of mild to moderate asthma by inhalation in between the attacks. - block antigenic stimuli’s of mast cell - in combination with bronchodilator effect of B2 agonists is best prophylaxis e.g. exercise
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Allergic rhinitis or hay fever.
Adverse Effects:
- The adverse effects are minor & localized at the site of deposition, in the form of throat irritation, cough, mouth dryness, chest tightness and wheezing.
- may lead to bronchospasm. These symptoms can be prevented by inhaling B2 agonist before cromolyen inhalation.
B- KETOTIFEN - same as above mechanisms
In addition it has antihistaminic effect due to blockade of (HI) receptors. It is given orally; chronic prophylaxis effect - ++ .
Side effects: sedation, dry mouth & dizziness.