pre finals pcol

• Respiratory system


  Includes air passages, pulmonary vessels, the lungs, and breathing muscles, aids the body in the exchange of gases between the air and blood, and between the blood and the body's billions of cells
• Functions of the respiratory system


  • Inhalation and Exhalation
  • Exchange of gas between the lungs and the bloodstream
  • Exchange of gas between bloodstream and body tissues
  • Air vibration in the vocal cords create sounds
  • Olfaction
• Respiratory drugs


  • Antihistamine
  • Decongestants
  • Antitussive
  • Expectorants
  • Bronchodilators
  • Other Respiratory Drugs
• Antihistamine


  Primarily act to block histamine effects that occur in an immediate (type I) hypersensitivity reaction, commonly called an allergic reaction
• Classes of antihistamines


  • Ethanolamines
  • Alkylamines
  • Phenothiazines
  • Piperidines
• Uses of antihistamines


  • Allergic rhinitis
  • Vasomotor rhinitis
  • Allergic conjunctivitis
  • Urticaria
  • Angioedema
• Pharmacokinetics of antihistamines


  • H1-receptor antagonists are absorbed well after oral or parenteral administration
  • Antihistamines are distributed widely throughout the body and central nervous system (CNS)
  • Loratadine is a nonsedating antihistamine
  • Antihistamines are metabolized by liver enzymes and excreted in urine, with small amounts secreted in breast milk
• Pharmacodynamics of antihistamines


  • Block the action of histamine on small blood vessels
  • Decrease arteriole dilation and tissue engorgement
  • Reduce leakage of plasma proteins and fluids out of the capillaries
  • Inhibit most smooth muscle responses to histamine
  • Relieve symptoms by acting on the terminal nerve endings in the skin
  • Suppress adrenal medulla stimulation, autonomic ganglia stimulation, and exocrine gland secretion
• Drug interactions of antihistamines

  • Epinephrine (reverse vasopressor effects producing vasodilation)
  • Aminoglycosides (mask toxic signs and symptoms of ototoxicity)
  • Tranquilizers and Alcohol (increases sedative and respiratory depressant effects)
  • Macrolide Antibiotics when taken with Loratadine (may cause serious cardiac effects)
• Adverse effects of antihistamines

  • Dizziness
  • Fatigue
  • Disturbed Coordination
  • Muscle Weakness
• Nursing responsibilities for antihistamines

  • Monitor the patient for adverse reactions and drug interactions
  • Monitor blood counts during long-term therapy; watch for signs of blood dyscrasia
  • Take the drug with meals or snacks to prevent GI upset
  • Avoid caffeine, nicotine, and alcohol
  • Use warm water rinses, artificial saliva, ice chips, or sugarless gum or candy to relieve dry mouth
  • Take medication to prevent motion sickness 30 minutes before travel
  • Avoid hazardous activities such as driving until the full CNS effects of the drug are known
  • Stop taking antihistamines 4 days before diagnostic skin tests
  • Notify the prescriber if tolerance develops
  • Use sunblock or wear protective clothing due to photosensitivity
  • Avoid using other products containing diphenhydramine while breast-feeding
  • Administer the drug 20 minutes before hours of sleep if using for insomnia
• Decongestants


  Used to relieve the symptoms of swollen nasal membranes resulting from allergic rhinitis, vasomotor rhinitis, acute coryza, sinusitis, or common cold
• Types of decongestants


  • Systemic Decongestants (Sympathomimetic drugs)
  • Topical Decongestants (Vasoconstrictors)
• Pharmacokinetics of systemic decongestants

  • Absorbed readily from the GI tract and widely distributed throughout the body into various tissues and fluids
  • Slowly and incompletely metabolized by the liver and excreted largely unchanged in the urine within 24 hours of oral administration
• Pharmacodynamics of decongestants


  • Cause vasoconstriction by directly stimulating alpha adrenergic receptors in the blood vessels of the body
  • May also act indirectly resulting in the release of norepinephrine from storage sites in the body which leads to peripheral vasoconstriction
• Drug interactions of decongestants


  • Sympathomimetic Drugs like epinephrine (Increased CNS Stimulation)
  • MAO Inhibitors (may cause hypertensive crisis)
  • Alkalinizing drugs (may increase the effects of pseudoephedrine by reducing the urinary excretion)
• Adverse effects of decongestants

  • Nervousness
  • Restlessness and insomnia
  • Nausea
  • Palpitations and tachycardia
  • Difficulty urinating
  • Elevated blood pressure
  • Rebound nasal congestion with prolonged topical use
  • Burning of nasal mucosa, sneezing and mucosal dryness or ulceration
• Nursing responsibilities for decongestants


  • Encourage the patient to perform deep-breathing exercises
  • Advise the patient not to take other medications, OTC products, or herbal remedies
  • Don't crush or break extended-release forms of the drug
  • Give the last dose at least 2 hours before bedtime to minimize insomnia
  • Instruct patient to limit the use of intranasal forms to 3-5 days to prevent rebound decongestion
• Antitussives


  Suppress or inhibit coughing, used to treat dry nonproductive cough
• Major antitussives


  • Benzonatate
  • Codeine
  • Dextromethorphan hydrobromide
  • Hydrocodone bitartrate
• Pharmacokinetics of antitussives


  • Absorbed well through the GI tract, metabolized in the liver, and excreted in urine
  • Opioid antitussives excreted in breastmilk and should be used during in pregnancy only if the benefits are safe to risks
• Pharmacodynamics of antitussives


  • Benzonatate relieves cough caused by pneumonia, bronchitis, the common cold, and chronic pulmonary diseases
  • Dextromethorphan is the most widely used cough suppressant, not associated with sedation, respiratory depression, or addiction at usual dosages
• Drug interactions of antitussives

  • MAOIs (may cause excitation, an extremely elevated temperature, hypertension or hypotension, and coma)
  • Benzonatate needed to be swallowed whole, chewing or crushing can produce a local anesthetic effect in the mouth which can compromise the airway
• Adverse effects of antitussives

  • Dizziness
  • Sedation
  • Headache
  • Nasal congestion
  • Burning in the eyes
  • GI upset or nausea
  • Constipation
  • Skin rash, eruptions, or itching
  • Chills
  • Chest numbness
• Nursing responsibilities for antitussives

  • Report ineffectiveness of the drug to the prescriber
  • Encourage the patient to perform deep-breathing exercises
  • Advise the patient not to take other medications, OTC products, or herbal remedies
  • Tell the patient taking an opioid antitussive to avoid driving and drinking alcohol
  • Monitor the patient's hydration level if adverse GI reactions occur
• Expectorants


  Increase bronchial secretions, which, in turn, thin mucus so that it's cleared more easily out of airways
• Guaifenesin


  The most commonly used expectorant, helps make mucus easier to cough up and is used for the relief of symptoms caused by productive coughs
• Pharmacokinetics of guaifenesin


  Absorbed through the GI tract, metabolized by the liver, and excreted primarily by the kidneys
• Pharmacodynamics of expectorants


  • Reduces the thickness, adhesiveness, and surface tension of mucus, making it easier to clear it from the airways
  • Provides a soothing effect on mucous membranes of the respiratory tract
• Guaifenesin isn't known to have specific drug interactions
• Adverse effects of expectorants

  • Vomiting (if taken in large doses)
  • Diarrhea
  • Drowsiness
  • Nausea
  • Abdominal pain
  • Headache
  • Hives or skin rash
• Nursing responsibilities for expectorants

  • Assess the patient's sputum production before and after giving the drug
  • Be aware that the drug may interfere with laboratory tests for 5- hydroxy indoleacetic acid and vanillylmandelic acid
  • Encourage the patient to perform deep-breathing exercises
  • Advise the patient not to take other medications, OTC products, or herbal remedies
• Other respiratory drugs


  • Beta2 Adrenergic Agonists
  • Bronchodilator (Ipratropium)
  • Corticosteroids
  • Mast Cell Stabilizers
  • Methylxanthines
• Beta2 adrenergic agonists


  • Used for the treatment of symptoms associated with asthma and chronic obstructive pulmonary disease (COPD)
  • Can be divided into short-acting and long-acting agents
• Short-acting beta2 adrenergic agonists

  • Albuterol (systemic, inhalation)
  • Levalbuterol (inhalation)
  • Terbutaline (systemic)
• Long-acting beta2 adrenergic agonists

  • Albuterol (oral, systemic)
  • Formoterol (inhalation)
  • Salmeterol (inhalation)
  • Arformoterol
  • Olodaterol
• Short-acting inhaled beta2 adrenergic agonists

  The drugs of choice for fast relief of symptoms in asthmatic patients, primarily used as a need basis of prn basis for asthma and COPD and are also effective for prevention for exercise induce asthma
• Long-acting beta2 adrenergic agonists

  Used with anti-inflammatory agents, specifically inhaled corticosteroids, to control and prevent symptoms of asthma and COPD
• Drug classes affecting the respiratory system

  • Beta2 adrenergic agonists
  • Ipratropium
  • Corticosteroids
  • Leukotriene-modifiers
  • Mast cell stabilizers
  • Methylxanthines
• Beta2 adrenergic agonists


  • Used for the treatment of symptoms associated with asthma and chronic obstructive pulmonary disease (COPD)
  • Can be divided into short-acting and long-acting agents