Respiratory drugs Flashcards
1
Q
B2 agonists
sympathomimetics
A
- These are sympathomimetics that cause bronchodilation.
- They bind to B2 receptors in bronchiols and cause bronchodilation. (by binding to Gs protein, that stimulates AC causing increased synthesis of cAMP causing relaxation of bronchial muscles.
- Since they bind to B receptors elsewhere they have other side effects: arrythmias, tremors, headache and dizziness.
So they are contraindicated in patients with cardiac problems.
2
Q
Adrenaline
A
- Non-selective rapid bronchodilator.
- Given S.C. or as inhaled microaerosol.
3
Q
Salbutamol + Fenoterol + Terbutaline
A
- SABA - short acting B2 agonists
- These are short acting, they cause bronchodilation in 5 minutes. Reach maximum bronchodilation within 30-60 minutes and persist for 2 hours.
4
Q
Formoterol + Salmeterol + Procaterol
A
- LABA - long acting B2 agonists
- These are long acting, so cause bronchodilation for longer periods (12 hours).
- Are NEVER given in acute exacerbations. And never without an inhaled corticosteroid.
5
Q
Ipratropium + Tiotropium
A
- Muscarinic antagonists - anticholinergics - these bind to muscarinic receptors and inhibit them. By that they decrease ACh effects so inhibit bronchoconstriction.
- They don’t diffuse to the blood so don’t reach the CNS so they have minimal systemic side effects.
- Ipratropium has short duration of action - 3-5 hours.
- Tiotropium has longer duration of action - 24 hours.
- They are derivatives of atropine and are given in aerosol inhalation.
5
Q
Theophylline
A
- At low doses blocks adenosine receptor causing decrease in adenosine effects so inhibits constriction of smooth muscles and inhibit release of mediators from mast cells.
- At high doses inhibits PDE (phosphodiesterase) so causes decrease in conversion of cAMP to 5-AMP. As a result cAMP accumulates and causes bronchodilation.
- Theophylline levels above >20mg/L can cause unwanted side effects, like nausea and vomiting. And levels >40mg/L can lead to seizures or arrhythmias.
- Half life decreases by: erythromycin, cimetidine, ciproflaxacin…
- Half life increases by: phenytoin, carbamazepine, rifampicin…
- More PDE inhibitors are Theobromin and caffeine.
6
Q
Roflumilast
A
- Inhibits PDE4 so decreases conversion of cAMP to AMP. As a result cAMP accumulates and causes bronchodilation.
- It is used more in COPD.
7
Q
Zileuton
A
- Selective 5-Lipooxygenase inhibitor.
- Decreases synthesis of LTC4, LTD4, LTB4… Leading to bronchodilation and decreases inflammation.
8
Q
Zafirlukast + Pranlukast + Montelukast
A
- Selective inhibitors of cysteinyl leukotriene 1 receptors.
- They block the receptors to leukotrienes so decreases their effects. Leading to bronchodilation and decrease inflammation.
9
Q
Beclomethasone + Fluticasone + Budesonide
A
- ICS - inhaled corticosteroids.
- They bind to their receptors in the cytoplasm and have many effects: decrease cytokine synthesis, decrease some enzyme synthesis, and more that add to decreased inflammatory response.
- As a bonus they also induce expression of genes that synthesize B2 receptors, which will further increase the effect of B2 agonists if taken together.
- They are given by inhalation to prevent the unwanted systemic side effects.
- They can still have side effects like oropharyngeal candidiasis (which can be prevented by mouthwash) or dysphonia.
- I.V. or P.O. administration of corticosteroids has many side effects relating to cushing syndrome because corticosteroids are everywhere in our body.
- Sudden stop of corticosteroid administration can lead to adrenal insufficiency syndrome.
10
Q
Cromolyn + Sodium Cromoglycate + Sodium Nedocromil
A
- These drugs inhibit degranulation of mast cells, so prevent release of histamine. As a result prevent inflammation.
11
Q
Omalizumab
A
- Anti IgE antibody - inhibits its binding to mast cells.
As a result the effect of mast cells decrease and by that inflammation is decreased. - This is indicated in patients who don’t use GCS and have sensitivity to aero-allergens.
12
Q
Reslizumab
A
- Anti IL-5 antibody - inhibits its action so inhibits maturation, recruitment of eosinophils.
- Indicated in patients with severe asthma aged >18 years with eosinophilic phenotype.
13
Q
Mepolizumab
A
- Anti IL-5 antibody - inhibits its binding to its receptor on eosinophils.
- Indicated in patients >12 years with eosinophilic phenotype.
14
Q
Antitussives
A
Opioid antitussives: directly suppress the cough center in medulla.
- Codeine, Hydrocodone and Pholcodine.
Non opioid antitussives: prevent cough by preventing its stimulation.
- Benzonatate, Dextromethorphan and Butamirate.
