bronchodilators and antihistamines Flashcards
What is the best form of treatment for Asthma?
Treat with an anti-inflammatory for prophylactic treatment and use a bronchodilator for symptomatic treatment.
What is the best treatment for COPD?
Triple Therapy = anti-cholinergic, bronchodilator, and anti-inflammatory
What are the 3 aerosol delivery methods?
Metered-dose inhaler, nebulizers, and dry-powder inhaler
What are the main uses of short acting beta-agonists?
Immediate treatment of bronchospasm or prophylaxis of exercise-induced asthma
What is the mechanism of action of beta-agonists?
Stimulates the Gs subunit activating adenylyl cyclase causing bronchodilation and inhibition of mast cell degranulation (minor effect)
What are possible side effects of beta-agonists?
Overuse can cause systemic effects and activation of beta1 receptors
What is salmeterol? Describe it use and a similar drug.
Salemeterol is LABA which is typically used for the prophylaxis of night time asthma attacks.
Formoterol is similar.
What is an effect of long-term LABA therapy? How can this be avoided?
Long-term therapy with LABAs can cause decreased effectivity of SABA in rescue therapy. This effect can be avoided by combining therapy with inhaled corticosteroids.
Note: Once asthma has been stabilized, remove LABBA therapy if possible, and use just inhaled corticosteroids.
What are the situations in which oral Beta-agonists should be used?
Briefly, in children who cannot operate their inhaler due to age or URI. Patients where use of inhaler causes exacerbation of asthma.
What are the adverse effects of beta-agonists?
Skeletal musle tremors, tachycardia, hypokalemia, and hyperglycemia
What are ipratropium and tiotropium? How are they delivered?
Both of these are quaternary amine muscarinic antagonists. They cause bronchodilation, but do not enter the CNS or GI tract easily. Ipratropium is only an inhaled aerosol, while tiotropium is a dry powder.
What is the principal use of ipratropium?
Used in combination with albuterol to treat COPD.
What is the mechanism of action of theophylline?
Blocks adrenergic receptors, lowers intracellular calcium, and hyperpolarizes cell membranes
Why is theophylline no longer a 1st line agent for asthma?
It has a modest effect and narrow therapeutic window requiring periodic monitoring of blood levels.
What is the mechanism of action for corticosteroids?
Bind to the intracellular steroid receptor and regulate transcription.
When is corticosteroid therapy indicated in an asthmatic?
When a patient requires the use of a beta-agonist more than 4 times a week
What drugs are used in systemic corticosteroid therapy? When would such a therapy be indicated in an asthmatic patient?
Methyprednisone and prednisone should be used in severe acute asthma exacerbations.
What are potential side effects of corticosteroid therapy?
The most common adverse effects are candidiasis and dysphonia due to the oral depostion of drug. Can also see osteoporosis, metabolic disorders, hypothalamic suppression, and skin-thinning
What is the MOA of cromolyn compounds? what are their uses?
Cromolyn sodium is DIRECT inhibitor of histaminer release and INDIRECTLY inhibits antigen-induced bronchospasmm. these drugs are used for prophylactic therapy.
What is montelukast and it’s use?
This is a leukotriene inhibitor which binds the LTD4 receptor. Used for oral prophylaxis of exercise and aspirin induced asthmas.
What is the mechanism MOA of antihistamines?
Block the H1 receptor and most effects of histamine
What is the difference between 1st generation and 2nd generation anti-histamines?
1st generation - cross the BBB and can cause sedation
2nd generation - do not cross the BBB
What are the clinical indications of anti-histamines?
Allergic conditions - rhinitis, urticaria, conjunctivitis, anaphylaxis (adjunct with epi)
Note: not effective against bronchial asthma
Can also be used for motion sickness and insomnia
What are the first genertation antihistamines?
Diphenhydramine, chlorpheniramine, and promethazine
What are the second generation antihistamines?
Fexofenadine, loratidine, and cetirizine
What are the clinical effects of anti-histamines?
relieve itching, nasal discharge, and sneezing. Not a decongestant.
What are the side effects of anti-histamines?
First-Gen Only = Sedation, CNS disturbances, dry mouth, and urinary retention
Second-Gen = GI disturbances (also first-gen)
What type of drug is used for congestion?
alpha-agonists: phenylephrine, pseudoephedrine, all the zolines
What are two opioid anti-tussives?
Dextromethorphan and codeine
How do opioids eliminate cough?
Enter the CNS and suppress the cough reflex.
What are two expectorants?
N-acetyl-cysteine and guaifenesin
What is the most effective drug for relief of allergic rhinitis?
Intranasal corticosteroids
What is amantadine?
This is an antiviral used to prevent type A influenza
