Respiratory System Pharmacology Flashcards
Parasympathetic stimulation of airway smooth muscle via muscarinic M3 receptors causes…
Constriction of airways.
How do the alveoli get rid of dust and debris without cilia?
They contain phagocytic cells
Treatment of pulmonary embolism is with…
…anticoagulant medication.
Examples of URT diseases
Sinusitis
Tonsilitis
Laryngitis
Allergic rhinitis
Cough
What are the mediators of the cough reflex
Cough reflex is via both the afferent and efferent nerves (i.e. involving the central and peripheral nervous systems), as well as the smooth muscles of the bronchial tree.
Types of antitussives
Centrally-acting
Peripherally-acting
Types of centrally-acting antitussives
Narcotics
Non-narcotics
Examples of narcotics used as antitussives
Codeine, Pholcodeine, Hydrocodone, Morphine.
Opioid derivatives like Dextromethorphan, Levopropozyphene, Noscapine
Examples of non-narcotics used as antitussives
Benzonatate, dimemorfan, benproperine, first generation Antihistamines e.g. diphenhydramine
Examples of peripherally-acting antitussives
Diphenhydramine, Benzonatate
Antitussives MOA
Centrally:
- Depressing the medullary centre or associated higher centres.
- Increase threshold of cough centre
Peripherally:
- Interrupt tussal impulses in the respiratory tract.
- Inhibit conduction along motor pathways.
Pharmacological action of expectorants
aka Mucokinetics, they make cough more productive by loosening and liquefying bronchial secretions
Reflexly-acting mucokinetics examples
a. Ipecacuanha
b. Ammonium chloride
c. Potassium iodide
Directly-acting mucokinetics examples
Guaiphenesin
Pharmacological action of mucolytics
Break down thick mucus, making it thinner and easier to cough out. Split disulphide bonds in mucoprotein present in sputum and reduces its viscosity.
Examples of demulcents
Liquorice, Glycerin, Lozenges
Examples of mucolytics
Acetylcysteine
Carbocysteine
Methylcysteine
Lower respiratory tract disorders include
Infections
Restrictive pulmonary disorders Obstructive pulmonary disorders Lung cancer.
‘A nonproductive cough turns into a deep cough that will expectorate mucus and sometimes pus’ describes which condition?
Acute bronchitis
Risk factors for asthma
Genetic
Environmental
Genetic risk factors for asthma
Atropy
Gender
Race/ethnicity
Environmental risk factors for asthma
Smoking
Allergens
Occupational sensitizers
Respiratory infections
Parasitic infections
Perinatal risk factors
Diet and nutrition
Asthma symptoms
Cough
Wheezing
Shortness of breath
Chest tightness
Phases of allergic induction in asthma
- Induction of allergic reaction involving antigen uptake, processing and presentation
- Early-phase asthmatic reaction (EAR),
- Late-phase asthmatic reactions (LAR), and
- Chronic allergic inflammation.
Which acute signs and symptoms are associated with EAR
- Mild rhinitis
- Anaphylactic shock
- Vasodilation
- Contraction of the bronchial smooth muscle (producing airflow obstruction and wheezing)
- Increased mucus secretion (exacerbating airflow obstruction in the lower airways).
Granule basic proteins synthesised by eosinophils
- Major basic proteins (MBP)
- Eosinophil cationic protein (ECP)
- Eosinophil peroxidase (EPO)
- Eosinophil-derived neurotoxin (EDN)
Lipid mediators generated by eosinophils
Prostaglandins and cysteinyl leukotrienes)
Cytokines produced by eosinophils
Tumour necrosis factor and transforming growth factor beta (TNF, TGF-β), IL-4 and IL-13 and chemokines.
Cytokines produced by eosinophils
Tumour necrosis factor and transforming growth factor beta (TNF, TGF-β), IL-4 and IL-13 and chemokines.
Categories of Asthma
- Mild intermittent (occasional attacks)
- Mild persistent (> 2 attacks/week)
- Moderate persistent (daily attacks)
- Severe persistent
Classes of drugs used for asthma treatment
Bronchodilators
Corticosteroids
Mediator antagonists
Mast cell stabilizers
Anti-IgE antibody
Types of bronchodilators
Sympathomimetics-β2-receptor agonists
Xanthine derivatives
Anticholinergic drugs
Monoclonal antibodies
Prophylactic agents
Examples of Sympathomimetics-β2-receptor agonists
i. Short-acting: salbutamol, pirbuterol, terbutaline
ii. Long-acting: salmeterol, formoterol
Examples of Xanthine derivatives
Theophylline (water insoluble)
Theophylline + Ethylene Di-Amine = Aminophylline
Anticholinergic drugs examples
Short-acting: ipratropium
Long-acting: tiotropium
Anti-inflammatory drugs
Corticosteroids
Systemic drugs
Corticosteroids examples
Corticosteroids:
1. Topical/inhalation:
- betamethasone
- beclomethasone
2. Systemic:
- oral: predisone, prednisolone
- i.v: hydrocortisone
Example of monoclonal antibodies
Omalizumab
Classes of prophylactic agents
Mast cell stabilisers
Mediator antagonists
Leukotriene pathway inhibitors
Examples of mast-cell stabilizers
i. Cromones: Na cromoglycate, Nedocromil Na
ii. Ketotifen
Examples of antihistamines
Azelastine, cetirizine
Leukotriene pathway inhibitors
- 5-lipoxygenase enzyme inhibitor
- Leukotriene-receptor antagonists
Examples of 5-lipoxygenase enzyme inhibitors
Zileuton
Mild intermittent asthma treatment
Use short-acting inhaled β2-adrenoceptor agonists
Moderate persistent asthma treatment
inhaled steroids + long-acting bronchodilator; antileukotriene drug
Severe persistent asthma treatment
high dose inhaled steroids; oral steroids and if very severe give i.v steroids + bronchodilator. Very severe (status asthmaticus) will require hospitalization and oxygen gas.
Among the symptoms of COPD are:
cough, wheeze, excessive secretion, shortness of breath, chest tightness.
What causes breathing difficulties in COPD
- the airways and air sacs lose their elastic quality.
- the walls between many of the air sacs are destroyed.
- the walls of the airways become thick and inflamed.
- the airways produce more mucus than usual, which can clog them.
Pharmacological action of analeptics
They antagonize drug-induced depression of the central nervous system. They act primarily on the medullary center and stimulate the central nervous system, which act to increase the action of the respiratory system
How are analeptics used?
- Acute exacerbations of chronic lung diseases with hypercapnia, drowsiness and inability to cough.
- Apnea in premature infants.
- Obesity-hypoventilation syndrome.
- In some patients with COPD and alveolar hypoventilation.
Examples of clinically used analeptics
Doxapram and Amphifinazole
Clinical uses of doxapram
For treating respiratory depression in patients who have taken excessive doses of drugs such as buprenorphine (an opioid for treating opioid addiction and pain), which may fail to respond adequately to treatment with naloxone.
Other analeptics:
- Picrotoxin
- Biccuculline
- Strychnine
- Pentylenetetrazol (leptazol)
- Nikethamide
