Focus on Pharmacology Essentials for Health Professionals Jahangir Moini, MD, MPH Chapter 25 Effects of Drugs on Respiratory Disorders

Asthma Chronic disease caused by increased reactivity of the tracheobronchial tree to various stimuli Affects about 16 million Americans Classified according to cause: allergy, exercise-induced, or infections of respiratory tract

Isoproterenol Isoproterenol (Isuprel) is often used to treat asthma in children However, this use is not a labeled indication for the drug Advise parents and children that saliva and sputum may appear pink after inhalation—this is normal

Bronchodilators Agents that widen the diameter of bronchial tubes:

Corticosteroids: Uses Mechanism of action believed to be diminished activation of inflammatory cells and increased production of anti-inflammatory mediators, which reduces production of mucus and decreases edema Used to treat respiratory conditions such as nasal congestion and allergic conditions such as rhinitis and asthma

Corticosteroids: Adverse Effects Irritation of mucous membranes Headache Pharyngitis Epistaxis Nausea and vomiting Coughing

Corticosteroids: Contraindications Contraindicated in children younger than 4 years Cautious use in pregnancy and lactation, and in those with immune system infections, tuberculosis, herpes simplex, ulcers, and nasal surgery or trauma

Mast Cell Stabilizers: Uses Inhibit release of bronchoconstrictors such as histamine from pulmonary mast cells (cells in connective tissue) Used for prophylaxis of mild to moderate seasonal bronchial asthma and allergic rhinitis; prevention of exercise-related bronchospasm; prevention of acute bronchospasm

Mast Cell Stabilizers: Adverse Effects Nausea and vomiting Dry mouth Throat irritation Cough Hoarseness Headache Dizziness Rash

Mast Cell Stabilizers: Contraindications Contraindicated in patients with coronary artery disease or history of arrhythmias, acute asthma, during pregnancy; or in children younger than 6 years

Mast Cell Stabilizers: Patient Information Advise patients to gargle with water or to suck on lozenges after each treatment to reduce throat irritation, cough, and hoarseness.

Antitussives: Uses Opioids work by causing respiratory depression; nonopioids reduce activity of peripheral cough receptors and appear to increase threshold of central cough centerl. Opioids are used to suppress nonproductive cough; nonopioids offer temporary relief of cough spasms.

Antitussives: Adverse Effects Difficulty breathing Drowsiness Rash Itching Dizziness Nausea Nervousness and restlessness

Antitussives: Contraindications Contraindicated in asthma, emphysema, diabetes, heart disease, seizures, thyroid conditions, chronic bronchitis, and liver disease. Cautious use in pregnancy and lactation

Antitussives: Patient Information Advise patients to call physician if coughing continues longer than 1 week or mucus is yellow.

Natural Expectorant Wild cherry bark acts as an expectorant and a mild sedative. It is available in syrup or tincture forms. It should not be used during pregnancy.

Opioids for Cough Opioid analgesics are among most effective drugs used as cough suppressants: 15-mg doses are often sufficient.

Expectorants and Mucolytics: Uses Work by lowering viscosity and facilitating removal of mucous secretions or enhancing reflex outflow of respiratory tract fluids by irritating gastric mucosa (guaifenesin) Used to treat bronchopulmonary disease and cystic fibrosis

Expectorants and Mucolytics: Adverse Effects and Contraindications Common adverse effects: very few Contraindicated in pregnancy and lactation. Guaifenesin may interact with heparin.

Expectorants and Mucolytics: Patient Information Instruct patients to increase fluid intake. Tell patients to report a persistent cough beyond 1 week.

Decongestants: Uses Vasoconstricting agents that shrink swollen mucous membranes of nasal airway passage Used for relief of nasal congestion due to common cold, upper respiratory allergies, and sinusitis.

Decongestants: Adverse Effects Nervousness and restlessness Insomnia Dizziness Headache Irritability

Decongestants: Contraindications Diabetes Heart disease Uncontrolled hypertension Hyperthyroidism

Decongestants: Patient Information Instruct patients to avoid taking oral decongestants with 2 hours of bedtime because they may act as stimulants. Advise patients to discontinue and immediately report extreme restlessness or signs of sensitivity. Women should not breast feed.