Lecture 53 - Drugs for Lung Disease; Anti-tussives; Anti-histamines Flashcards
what drug classes are used in the setting of Asthma and COPD acute exacerbations ?
○ SABA
○ Short-acting anticholinergics
○ Systemic corticosteroids
What drugs are used as maintenance therapy for asthma?
§ ICS § LABA (in conjunction with ICS) § Cromolyn and Nedocromil § Leukotriene modifiers § Omalizumab
What drugs are used as maintenance therapy for COPD?
§ Long-acting anticholinergics
§ LABA
Bronchodilators for COPD and Asthma?
Beta2 Agonists
Anticholinergics
Methylxanthines
Mechanism of Beta 2 agonists?
Stimulates beta2 receptors causing an increase in cAMP which causes smooth muscle relaxation (bronchodilation), mast cell stabilization and skeletal muscle stimulation
Side effects of SABA and LABA
Tachycardia/palpitations
Transient decrease in serum potassium levels
Tremors
Lactic acidosis
LABA – same as above, but also carry increased risk of asthma realted death when not used with corticosteroids
Anticholinergics
- what are some drugs?
- mechanism
Ipratropium bromide (short-acting) Tiotropium (long-acting)
Inhibit muscarinic receptors (M1 and M3) in bronchial smooth muscle which blocks Ach binding and increases cGMP which leads to bronchodilation
Anticholinergics – side effects?
Blurred vision Dry mouth Nausea Urinary retention CNS effects Tachycardia Increased CV events
Methylxanthines –
- what drug is in this class?
- mechanism ?
Theophylline
Non-selective inhibition of phosphodiesterase which increases cAMP and cGMP bronchodilation
Inflammatory cell regulation
Competitive antagonist of adenosine and stimulates endogenous catecholamine release (beta2 bronchodilation)
Why is Theophylline rarely used clinically ?
what are some side effects?
narrow therapeutic window
Nausea and vomiting Gastric upset Tachyarrhythmia Jitteriness Insomnia Headache seizures
Corticosteroids —
indications for use
– what are they drugs? which has the lowest potency, which has the highest?
Acute exacerbation of asthma and COPD
maintenance therapy to prevent bronchospasm
allergic rhinitis
Hydrocortisone (low potency)
Prednisone (medium potency)
Methylprednisone (medium potency)
Dexamathasone (high potency)
Side effects of corticosteroids
– what specific infection can occur with inhaled corticosteroids?
Acute setting: Hypergylcemia, HTN,
Long term: HPA suppression, growth retardation, muscle myopathy, osteoporosis, impaired wound healing
Oral steroids – candidiasis
Mast Cell Stabilizing Drugs - what are they? mechansim? indications?
Cromolyn
Nedocromil
Inhibits mast cell degranulation
Long term treatment for prevention of symptoms of asthma
Side effects of mast cell stabilizing drugs?
cromolyn: Cough and wheezing
Nedocromil – Cough and wheezing + dyguesia
Leukotriene Modifiers
two types? (different mechanisms)
what are the drugs?
Leukotriene receptor antagonists — • Zafirlukast (Accolate); Montelukast (Singular; taken once a day)
5-lipoxygenase inhibitor that prevents conversion from arachindonic acid to leukotrienes
Zileuton
Indications for the use of leukotrinee modifiers?
side effects for each class?
why is Zileuton not really used ?
◊ Long term control and prevention in patients with asthma
Allergic rhinitis
Luekotriene Antagonists: Headache
Nausea
Abdominal pain
Zileuton –
Liver toxicity
Hyperbilirubinemia
Antihistamines
mechanism?
whats the difference between first and second generation?
Competitive antagonist to H1-receptors that prevent histamine binding and action which will allow for bronchodilation (and effects on vascular smooth muscle and endothelial cells as well as nerves)
First generation: lipophilic and non-selective, anticholinergic effects
Same mechanism as above
Second generation: specific to peripheral histamine receptor
what are some first generation anti-histamines drugs?
Indications?
side effects?
Diphenhydramine HCl
Hydroxyzine
Promethazine
Allergic reactions
Allergic rhinitis
Anti-emetic
Anti-cholinergic effects: dry mouth, drowsiness, urinary retention, blurry vision
GI effects: nausea, abdominal pain
CNS effects: sedation, drowsiness
what are some second generation anti-histamines ?
Indications?
side effects?
Cetirizine/Levocetirizine
Loratidine
Fexofenadine
same indications
Low to none sedative, GI or anti-cholinergic effects
Antitussives:
- mechanism of the following drugs:
Opioids: (Codeine, Hydrocodone, Hydromorphone)
Dextromethorphan
Acts centrally on respiratory center in medulla and nucleus tractus solitaris to increase cough threshold
Side effects of opioids
side effect of Dextromethrophan
Nausea and vomiting
Sedation
Constipation
CNS effects at high doses: confusion, excitation, nervousness, irritability
Respiratory depression may occur with very high doses
Antitussive: Benzoate
mechanism:
side effects?
Anesthetic effect on stretch receptors of the vagal afferent fibers in the bronchi, alveoli and pleura —> blocking of cough reflex
May also suppress transmission of signal of cough reflex at medulla
Nausea Mucosal numbness (if you chew it)
Expectorant: Guaifenesin
mechanism –
indications –
Symptoms –
Loosens and thins lower respiratory secretions
Symptomatic relief of ineffective productive coughs
Nausea and vomiting
Dizziness
Diarrhea
