Pharmacology (Week 2) Flashcards
List some common Beta-2 Agonists
Salbutamol (short-acting - “SABA’s”)
Salmeterol (long-acting - “LABA’s”)
Indacaterol (ultra-long-acting)
MOA of Beta-2 Agonists:
Stimulate Beta-2 R’s in smooth muscle –> activates adenylate cyclase –> converts ATP to cAMP –> relaxation –> larger airway –> less resistance
Beta-2 Agonists typically used to treat what?
Asthma & COPD
Side effects of Beta-2 Agonists:
Overstimulation of Beta-1 and Beta-2 may lead to:
Tachycardia, palpitations, or tremor
Contraindications for giving Beta-2 Agonist:
Side effect is tachycardia so be cautious in patients where this would cause a problem:
- severe CAD
- arrhythmia
- aortic stenosis
For Asthma, what is the recommended treatment?
Beta-2 Agonists (LABA’s) combined with corticosteroids (because long-term corticosteroid use will upregulate the Beta-2 R’s in lungs.
Name a few prototypical anti-cholinergics.
Ipratropium
Long-acting muscarinic antagonists “LAMA” (tiotropium, aclidinium)
Explain the MOA of anti-cholinergics.
Antagonizes the muscarinic receptors which prevents bronchoconstriction and reduces secretions.
Ipratropium is non-selective for M1, M2, & M3.
Newer agents are more selective for M3.
How are anti-cholinergic drugs administered?
Inhalation.
They do not readily cross from alveoli into blood so ont much systemic absorption.
When are anti-cholinergics indicated?
Mostly for COPD (acute exacerbations or chronic use)
Contraindications of inhaled anti-cholinergics..
None of major significance
Side effects of inhaled anti-cholinergics..
Due to decreased parasympathetic stimulation..
Dry mouth, nose bleeds, nasal irritation.
What type of treatment is best for asthma?
Beta-2 Agonists
What type of treatment is best for COPD?
Anti-cholinergics..
But often anti-cholinergics will be combined with Beta-2 Agonists.
Sometimes ICS ( Inhaled Corticosteroids) is added and this is called “triple therapy”
Name some prototypical Leukotriene Receptor Antagonists (LTRA’s).
Montelukast
Zafirlukast
Explain the MOA of Leukotriene Receptor Antagonists.
Oral administration.
Blocks the LT1 Receptor (in lipoxygenase pathway)
–> Inhibits Bronchoconstriction and inflammation.
What are Leukotriene Receptor Antagonisits indicated for?
Used for asthma as a chronic and prophylactic medication (not for acute exacerbations).
List some side effects of LTRA’s.
headache, vomiting, diarrhea, and rarely Churg-Strauss Syndrome (allergic granulomatosis).
Name some prototypical Methylxanthines
Caffeine
Aminophylline
Explain the MOA of Methylxanthines.
Methylxanthines inhibit phosphodiesterases and therefore prevent cAMP breakdown –> cAMP causes bronchodilation.
Methylxanthines also inhibit adenosine (leading to side effects).
What are the indications for Methylxanthines?
As 2nd or 3rd line treatment of asthma & COPD.
What are the contraindications for Methylxanthines?
Because cAMP leads to increased contractility and HR, Methylxanthines should be avoided in patients with coronary heart disease.
What are some of the side effects of Methylxanthines?
Cardiac: arrhythmias
GI: nausea, vomiting
CNS: headache
Stimulatory effects: seizures, restlessness,
What is the significance of Roflumilast?
Similar to Methylxanthines. Selectively inhibits PDE-4. (PDE-4 is found in inflam cells) Roflumilast possesses more anti-inflam effect than methylxanthines. May be used to treat COPD.
List a couple prototypical Inhaled Corticosteroids.
Budesonide, Fluticasone.
Explain the MOA of Inhaled Corticosteroids.
Reaches lung alveoli –> gets to nucleus of cells –> inhibit expression of pro-inflam cytokines & COX-2.
Also have immunosuppresant effects.
When are Inhaled Corticosteroids indicated?
COPD and asthma.
What are some unwanted effects?
Catabolism: Inhibition of insulin --> increased blood glucose --> mobilization of Ca from bones --> increased muscle breakdown Anti-mitotic Water-retention
Thrush
Hoarseness
Sore throat
Osteoporosis
When would prednisone be used?
Only in severe asthma cases because it causes lots of side effects. (It is an oral medication).
List the targets of drug therapy for asthma and COPD.
Bronchoconstriction
Inflammation of airways
Mucous plugs
Remodelling
Which drugs are bronchodilators?
Beta-2 Agonists (via adrenergic sm m relaxation)
Anti-cholinergics (via decreased PSNS stimulation)
Methylxanthines (via PDE inhibition & increased cAMP)
What is omalizumab and how does it work?
It is a monoclonal antibody.
Prevents IgE from binding to allergen.
What drugs are best for controlling the progression of disease in asthma (ie. not the main ones used for relieving symptoms, but just controlling progression).
Inhaled corticosteroids
