Chapter 36 Respiratory Drugs 1

Question 1

Antihistamines

Answer 1

• Drugs that directly compete with histamine for specific receptors (H1 antagonists). H1 are found in areas such as smooth muscles surrounding blood vessels and bronchioles. Also affects secretions of lacrimal, salivary, and mucous glands (primary anticholinergic actions - drying).
• Bind to histamine receptors on mast cells and basophils which prevents the further release of histamines and actions.
• Loratadine and Diphenhydramine
• Used for histamine mediated disorders such as allergic rhinitis, analphylaxis, angioedema, drug fevers, insect bite reactions, urticaria.
• Most effective when given early
• Also used for vertigo, insomnia, motion sickness, cough, and symptoms of the common cold (sneezing and runny nose)

Question 2

Antihistamines contraindications, adverse effects, and interactions

Answer 2

• Contraindications include acute asthmatic attacks, lower respiratory disease, narrow-angle glaucoma, heart disease, kidney disease, hypertension, BPH, PUD, pregnancy, children (depending on the product)
• Adverse effects include dry mouth, difficulty urinating, constipation, changes in vision, drowsiness
• Interactions include alcohol, MAOIs ( also increase adverse effects), and CNS depressants increase CNS depressants effects.
• Ketoconazole, cimetidine, and erythromycin increases effects of antihistamines

Question 3

Decongestants

Answer 3

• Adrenergics (sympathomimetics): Pseudoephedrine/Sudafed (oral) and Oxymetazoline HCl/Dristan (nasal spray). These are the largest group.
• Adrenergics work by constricting small arterioles to upper respiratory infection to cause constriction to reduce swelling and allow secretions to drain
• Anticholinergics (parasympatholytics): Ipratropium bromide/Atrovent (nasal spray)
• Anticholinergics work by inhibiting secretions of the serous and serous-mucous membranes of the nasal passages
• Corticosteroids: Fluticasone propionate (Flonase), Beclomethasone dipropionate (Rivanase), and Budenoside (Pulmicort, pulmicort turbohaler, symbicort turbohaler).
• Corticosteroids work by targeting the inflammatory response; “turn off” immune cell response

Question 4

Decongestants contraindications, adverse effects, and interactions

Answer 4

• Contraindications include BPH, narrow angle glaucoma, uncontrolled cardiovascular disease, hypertension, diabetes, hyperthyroidism, prostatitis, asthma, TIAs, and inability to close eyes (stroke patients)
• Adverse effects include nervousness, insomnia, palpitations, tremors, local mucosal dryness and irritation, nose bleeds, mucosal thinning.
• MAOIs may result in additive pressor effects with adrenergics (blood pressure)

Question 5

Antitussives

Answer 5

• Drugs used to stop or reduce coughing. They are used only for nonproductive coughs. May also be used in cases in which coughing is harmful (post surgical).
• Opioids suppress the cough reflex by acting directly on the cough center in the medulla. They also have a drying effect on mucosa and an analgesic effect.
• Codeine and hydrocodone
• Nonopioids supress the cough reflex by numbing the stretch receptors in the respiratory tract and preventing the cough reflect from being stimulated. Also has a drying effect on mucosa but no analgesic effect.
• Dextromethrophan hydrobromide and Diphenhydramine

Question 6

Antitussives contraindications, adverse effects, and interactions

Answer 6

• Contraindications include opioid dependency, high risk for respiratory depression, alcohol use, COPD, anoxia, CNS depressants, increased intercranial pressure, impaired kidney and liver function
• Contraindications for dextromethrophan include hyperthyroidsim, cardiac disease, hypertension, glaucoma, MAOIs
• Adverse effects include sedation, nausea, vomiting, lightheadedness, constipation
• Interactions: may potentiate other opioids, tranquilizers, sedatives, hypnotics, MAOIs, alcohol
• Interactions of dextromethrophn: may potentiate MAOIs

Question 7

Expectorants

Answer 7

• Drugs that aid in the expectoration (removal) of mucous. Used in productive coughs.
• Reflex stimulation that causes irritation of the UR tract, loosening and thinning of respiratory tract secretions (result of the irritation). The final result is thinner mucus that is easier to remove.
• Guaifensin
• Used for common colds, bronchitis, laryngitis, pharyngitis, pertussis, influenza, measles

Question 8

Expectorants contraindications, adverse effects, and interactions

Answer 8

• Contraindications include hyperkalemia (for potassium containing expectorants)
• Adverse effects include nausea, vomiting, and gastric irritation
• Should be used with caution in older adults or patients with asthma or respiratory insufficiency. The increase in fluid intake and humidification may help liquefy and loosen secretions.