Respiratory, Antihistaminic and GI Drugs Flashcards
Conditions causing decreased O2 tension in the blood
Obstructive disorders Decreased breathing Cardiovascular conditions (Decreased contact surface area, increased diffusion distance, inconsistent lung aeration, and inconsistent lung circulation)
Respiratory stimulants/analeptics
Caffeine, doxapram
Indicated for: Drug overdose, decreased recovery time from anesthesia, and sleep apnea in infants
MOA: Mostly unknown, but some act on the medulla
Cautions: May potentiate depressant effects
Airway Remodeling
Permanent, negative changes to the respiratory system that may occur due to chronic irritation of the bronchioles. Increased collagen deposition, bulking of the airway smooth muscles, mast cell/goblet cell hyperplasia, and epithelial cell hypertrophy
Sympathomimetics
Albuterol, Epinephrine
Indicated for: Rescue drug for asthma, or other cases of COPD
MOA: Beta 2 agonist, relaxes smooth muscles of bronchioles. Often given through inhalation, or may be injected or given orally
Cautions: May cause tachycardia, palpitations, hypertension, nausea, vomiting, headache, and dizziness. Tolerance possible
Xanthines
Aminophylline/Theophylline
Indicated for: Asthma and pulmonary edema
MOA: Phosphodiesterase inhibitor which acts as a smooth muscle relaxant
Cautions: Gastric irritation, nausea, vomiting (acts directly on emetic center), retlessness, anxiety, convulsion, hypotension, headache
Usually given orally, may be given as IV bolus in emergencies
Anticholinergic
Ipratropium (Atrovent)
Indicated for: COPD (not asthma)
MOA: Inhibit cholinergic effects, preventing bronchoconstriction (simple bronchodilator)
Cautions: Drying effect, may aggravate asthma
Asthma Prophylactic/Mast Cell Stabilizers
Cromolyn
Indicated for: Asthma attack prevention (especially exercise-induced asthma)
MOA: Anti-inflammatory, prevents the release of histamine without cardiac stimulation
Cautions: May cause bronchospasm, throat irritation, headache, bitter taste.
Takes 2 weeks and 4 - 6 doses per day to become effective
Good especially for older patients
Leukotriene Receptor Antagonists
Indicated for: Asthma attack prevention, allergic rhinitis
MOA: Prevents leukotrienes from causing inflammation by blocking receptors
Caution: Heacache, GI upset, inhibits cytochrome P450 system so other drugs are metabolized more slowly
Corticosteroids
Dexamethasone
Indicated for: Conditions not managed by other medications. Asthma, COPD, status asthmaticus
MOA: Suppression of antibody formation, increase of cAMP for promoting bronchodilation, decrease of cGMP for decreasing bronchoconstriction
Local side effects: Hoarseness, dry mouth, local mouth/pharynx infections
Systemic side effects: Irreversible osteoporosis, cataracts, and growth stunting in children, reversible immunosuppression, salt/water retention, restlessness, insomnia, possible depression
Caution: Must be withdrawn slowly. Patient may need additional glucocorticoid during times of stress
Narcotic Antitussives
Codeine
Indicated for: Painful, exhausting, nonproductive cough
MOA: Suppresses cough center in medulla
Cautions: Potential for abuse, constipation, and respiratory depression
Use only if not managed with nonnarcotic antitussives
BEST TO TREAT CAUSE OF COUGH
Nonnarcotic Antitussives
Dextromethorphan
Indicated for: Painful, exhausting, nonproductive cough
MOA: Reduce activity of lung stretch receptors, or suppress cough center in medulla without analgesic/addictive properties (dextromethorphan)
Side effects not a concern if cough is severe enough to require this med
BEST TO TREAT CAUSE OF COUGH
Demulcents
Gargles, lozenges, syrups, steam treatment
Indicated for: Cough and throat irritation
MOA: Protects respiratory lining from irritation and contact with air
Expectorants
Indicated for: Asthma, COPD, bronchitis, pneumonia, coughs
MOA: Gastric irritants, make secretions more fluid so that irritants can be moved
Drugs which affect mucus
Mucolytic agents (enzymes Acetylcysteine Surface active drugs Diluents (water, saline) Dprnase Alfa (DNAase, used for cystic fibrosis)
Adrenergic agents
Indicated for: Nasal congestion from colds and allergies
MOA: Nasal vasoconstriction
Caution: Causes habituation
Intranasal steroids
Indicated for: Allergies
May increase risk of thrush, prevent healing of damaged nasal mucosa
Anithistaminics
Indicated for: allergies, cold symptoms
H1 receptors
Cause contraction of bronchial and intestinal smooth muscle and dilation of arterioles and capillaries when stimulated
H2 receptors
Cause increased gastric secretion when stimulated
H1 Antagonists
Chlorpheniramine, Cwetirizine, Meclizine
Indicated for: Prevention of allergic reaction, motion sickness
MOA: Prevents binding of stimulants to H1 receptors, depress CNS and decrease sensitivity of inner ear
Side effects: Drowsiness, sedation, dizziness, agitation, hallucination (first generation), dry mouth, blurred vision
Caution: Potentiate other sedative-hypnotics, asthma, blood dyscrasias
H2 Antagonists
Famotidine, Rantidine
Indicated for: Decrease gastric secretions to allow healing of ulcers, treat heartburn
MOA: Decrease gastric secretions
Side effects: Sometimes dizziness, diarrhea, muscle pain, rash, breast enlargement in some men, mental confusion in older patients
INHIBITS CP450, DECREASES DRUG METABOLISM
Systemic Antacids
Sodium Bicarbonate
Indicated for: Peptic ulcer, heartburn
MOA: Decrease stomach pH
May cause: Systemic alkylosis and electrolyte imbalance
Alters absorption of other drugs
Ninsystemic antacids
Aluminum, calcium, and magnesium compounds
Indicated for: Peptic ulcer, heartburn
May cause: constipation or diarrhea
Alters absorption of other drugs
Sedative/Antisecretory Agents
H2 Antagonists (inhibit gastric secretion)
Anticholinergic drugs
Prostaglandins (Reduce acid, increase mucus secretion; contraindicated in pregnancy due to possible miscarriage)
Proton Pump Inhibitors (Suppresses acid secretion, ma cause alkalinization
