Asthma/COPD drugs Flashcards
Systemic Coriticosteroid
Methylpredinsone
Aerosol corticosteroid
Fluticasone
B2 Adrenergic agonists
Albuterol, Salmetrol
Muscarinic Antagonists
Ipratropium Bromide, Tiotropium
Phosphodiesterase Inhibitors
Theophylline
Leukotriene Pathway Inhibitors
Montelukast
IgE inhibitors
Omalizumab
Characteristics of Early Reaction in Asthma
Histamine and Tryptase release from mast cells, airway wall smooth muscle contraction
Characteristics of late reaction in asthma
Interleukin and TNF release from T-lymphocytes, ECP, MBP release from eosinophils, protease release from neutrophils - cell infiltration.
Maintenance drugs vs quick relief medicines
Maintenance drugs affect AIRWAY RESPONSIVENESS/REACTIVITY to PREVENT attacks.
Quick relief medications relieve bronchoconstriction. They affect AIRWAY RESISTANCE and relieve constriction DURING ATTACKS.
There is overlap between the effects.
Deposition of inhaled drugs
10-20% inhaled. The rest gets swallowed, causing systemic and side effects.
Pharmacological target of leukotriene inhibitors
Neutrophils - IgE antibodies
Pharmacological target of muscarinic antagonists
Cholinergic reflex - inhibit bronchoconstriction
Pharmacological target of B2 adrenergic agonists
B2 receptors - bronchodilation
Most effective treatment to PREVENT asthma attacks
Inhaled glucocorticoids (ICS) - like all steroids they SUPPRESS INFLAMMATION but do not cure.
Chemically speaking, how do you increase the topical activity of a corticosteroid?
Substitution at the 17 alpha carbon
How do corticosteroids suppress inflammation?
They suppress transcription of inflammatory proteins. However, this means they have no effect on the release of pre-formed mediators like histamine.
Adverse effects of inhaled steroids
Candidiasis, and dysphonia
Suppression of hypothalamic-pituitary axis - leading to bone resorbtion, skin thinning, and growth retardation.
When should you use systemic glucocorticoids?
3-10 day treatment for severe asthma exacerbations.
B2 adrenergic agonists - use and effectiveness
Short acting - rescue
long acting - ONLY USED WITH ICS - most asthmatics can be controlled with ICS and an inhaled B2 agonists.
Short acting B2 agonist
Albuterolol
Long acting B2 agonist
Salmetrerol
Adverse effects of B2 agonists
Muscle tremor, tachycardia, hypokalemia - uncommon with short acting B2 agonists.
How many times a week should an asthmatic be using a rescue inhaler if the asthma is controlled?
1-2 times per week.
If you prescribe a long acting B2 agonist, what else are you prescribing?
ICS
Effects of muscarinic cholinergic antagonists
Block the effects of acetylcholine released from the vagus onto M3 receptors - reduce smooth muscle contraction and decrease mucus secretion. Generally not used in asthma unless intolerant of B2 agonists, potentially additive though.
Adverse effects of muscarinic antagonists
Dry mouth, possible urinary retention in old men with prostatic hypertrophy. Generally well tolerated because they are poorly absorbed.
Mechanism of methylxanthine drugs
Multiple potential mechanisms - Inhibits cAMP phosphodiesterase in smooth muscle, blocks activation of adenosine receptors on smooth muscle, decreased histamine deacytlation, decreases cytokine release.
Also, may strengthen the diaphragm in COPD.
Adverse effects of methyxanthines
Narrow therapeutic window - monitor plasma levels.
Nausea, vomiting,CNS stimulation - anxiety, convulsions, Cardiac - tachycardia, arrythmias (messing with adenosine screws up your AV node if I remember right)
Leukotriene inhibitors
PO, inhibit bronchoconstriction, add-on for mild to moderate asthma. Not helpful in COPD because it is not an inflammatory condition.
Adverse effects of leukotriene inhibitors
Hepatic dysfunction - rare. Reversible on discontinuation.
Anti IgE therapy
Reduces allergen-mediated activation of immune cells. Used SC at 2-4 wks, dose depends on Serum IgE. Adverse - $$$$
Definition of COPD
NON REVERSIBLE airflow limitation with or without symptoms.
