Drug Therapy for Asthma, Airway Inflammation, and Bronchoconstriction

Lower Respiratory Tract Disorders and Drug Therapy

• Conditions

  • Asthma

  • COPD

  • Respiratory Distress Syndrome

• Medications

  • Adrenergics

  • Anticholinergics

  • Xanthines

  • Corticosteroids

  • Leukotriene modifiers

  • Adjuvant medications

    • Mast cell stabilizers

    • Combination regimens

Asthma

• Characterized by airway inflammation, bronchoconstriction, & airway hyperresponsiveness to certain stimuli.

• Symptoms

  • Cough - especially at night, during exercise or laughter

  • Tachypnea

  • Chest tightness

  • Shortness of breath

  • Wheezing

Asthma Therapy Goals

• Minimal or no chronic symptoms day or night

• Minimal or no exacerbations or persistent airflow limitations

• Maintain normal activity levels; for children, no school/parent’s work missed

• Minimal use of short-acting inhaled beta2-agonist (less than one time per day, less than one canister per month)

• Minimal or no adverse effects from medications

• Minimize the risk of asthma-related deaths

Manifestations of COPD

• Air is trapped in the lower respiratory tract

• The alveoli degenerate and fuse together

• The exchange of gases is greatly impaired

Prevention and Treatment of COPD

• Reduce environmental exposure to irritants

• Smoking, vaping, huffing cessation

• Filters allergens from the air

• Avoid exposure to known irritants and allergens

• Open the conducting airways through muscular bronchodilation

• Decrease the effects of inflammation on the airway lining

Respiratory Distress Syndrome

• Characteristics

  • Progressive loss of lung compliance and increasing hypoxia

• Causes

  • Cardiovascular collapse, major burns, severe trauma, rapid depressurization, near drowning

• Treatment

  • Reversal of the underlying cause combined with need for ventilator support

Adrenergic

• Indication: Acute asthma attack, bronchospasms in acute or chronic asthma, and prevention of exercise-induced asthma

• Action: Beta2 selective adrenergic agonists, bronchodilators

• Contraindications: Depends on severity of the underlying condition

• Prototypes: albuterol (Proventil, Ventolin), epinephrine

• Pharmacokinetics: Rapidly distributed after injection, transformed in the liver to metabolites that are excreted in the urine

• Route: Varies by drug

• Adverse effects: sympathomimetic stimulation, CSN stimulation, GI upset, bronchospasm, cardiac arrhythmias, HTN, sweating, pallor and flushing

• Drug-drug interactions: general anesthetics

Short-Acting and Long-Term InhaledBeta2-Adrenergic Agonists

• Administering bronchodilators by inhalation is most effective and the initial treatment to relieve acute bronchoconstriction

• Two general types of inhaled beta2 adrenergic agonists are used for asthma management:

  • Rescue inhalant medications (quick relief, short-acting drugs) used during periods of acute symptoms and exacerbations

  • Maintenance inhalant medications (long-term control drugs used to achieve and maintain prophylactic control of persistent asthma.

Anticholinergics

• Indication: Maintenance treatment of bronchospasm associated with allergies, cold, or COPD

• Action: Blocks the muscarinic acetylcholine receptors in the smooth muscles of bronchi, inhibiting bronchoconstriction and mucus secretion

• Contraindications: Cautious use in conditions that would be aggravated by the anticholinergic effects of the drug – narrow-angle glaucoma, prostatic hypertrophy, and bladder neck obstruction

• Prototypes: ipratropium (Atrovent), tiotropium (Sprirva)

• Pharmacokinetics: Onset is 15 minutes when inhaled, peaks in 1-2 hours, and duration is 3-4 hours

• Route: Oral inhalation and nasal sprays

• Adverse effects: related to the anticholinergic effects of the drugs – dizziness, HA, fatigue, nervousness, dry mouth, sore throat, cough, nasal dryness, bronchospasm, hypotension, palpitations, blurred vision, rash, and urinary retention

• Evaluate pulse, B/P, respirations, adventitious sounds and urine output

Goals to Tx Lower Respiratory Tract

• Bronchodilation is essential to open up the airway to allow air to flow into the alveoli

• Alter the inflammatory process to decrease edema to further open the airways by reducing edema

• Drugs that alter inflammation process

  • Inhaled Steroids

  • Leukotriene Receptor antagonists

Xanthines (indication, action, contraindication, prototype, pharm)

• Indication: Symptomatic relief or prevention of bronchial asthma and for reversal of bronchospasm associated with COPD

• Action: Bronchodilation - direct effect on the smooth muscles of the respiratory tract, both in the bronchi and in the blood vessels dilate increasing vital capacity

• Contraindications: GI problems, coronary disease, respiratory dysfunction, renal or hepatic disease, alcoholism, or hyperthyroidism

• Prototype: Theophylline, aminophylline

• Pharmacokinetics: Narrow therapeutic margin, rapidly absorbed for the GI tract, metabolized in the liver and excreted in the urine, nicotine increases the metabolism

Xanthines (route, adverse rxn, d-d & food-d interaction, pt teaching)

• Route: Oral route has a rapid onset of minutes, peaks in 2-6 hours and duration lasts for 6-8 hours, do NOT chew enteric coated tablets; IV onset is immediate with peak within 30 minutes and duration of 4-8 hours

• Adverse effects: Related to theophylline levels in the blood (therapeutic range is 10-15 mcg/mL), CNS stimulant - seizures, tremors, GI upset, N, irritability, tachycardia, arrhythmias, palpitations, seizure, brain damage, fever, rash, bronchospasm, and even death

• Drug-drug interactions: Many drugs so always check when administering, together with ketamine results in Sz

• Food-drug interactions: Caffeine, cola, chocolate, tea

• Patient teaching: with or without food and why?

Xanthines (cautions, nursing interventions, evaluation)

• Contraindications/Cautions: known allergy, peptic ulcer, gastritis, renal or hepatic dysfunction, and coronary disease.

• Nursing Interventions: Monitor breath sounds, blood pressure, pulse, heart sounds, peripheral perfusion, and baseline ECG. Assess skins, liver and renal function, appropriate lab values as well as theophylline level. Administer PO with food or milk IF GI upset. Provide comfort measures including rest periods, quiet environment, dietary control of caffeine, and headache therapy as needed. Provide follow-up lab tests and patient teaching. Monitor for AE (CNS effects, cardiac arrhythmias, GI upset and local irritation. Monitor I & O. Avoid fatty meal. Monitor potassium and magnesium levels.

• Evaluate: Improved airflow, ease of respirations

Corticosteroids

• Anti-inflammatory agents

• Tx acute and chronic asthma

• Results in less mucus secretion, decreased airway mucosa edema, repairs epithelium damage, reduced airway reactivity

• Adverse effects: hyperglycemia, infection, water retention, HTN, MI, CVA, osteoporosis, hip problems, cataracts, HA, fungal infections, bronchospasm, adrenal suppression, decreased growth (children)

• Do not use as rescue medication

Inhaled Steroids (indication, action, contraindication, prototypes)

• Indications: Prevention and treatment of asthma, treat chronic steroid-dependent bronchial asthma

• Action: Decreases inflammatory response in the airways

• Contraindications: do NOT use for acute asthma attacks or for status asthmaticus since it is SLOW to respond

• Prototypes: beclomethasone (Qvar or Beconase), fluticasone (Flovent discus; Flovent HFA)

Inhaled Steroids (pharm, adverse rxn, nursing considerations)

• Pharmacokinetics: Well absorbed in resp. tract, metabolized by natural systems, mostly within the liver and excreted in urine

• Adverse effects: Sore throat, hoarseness, coughing, dry mouth, pharyngeal and laryngeal fungal infections

• Nursing considerations

  • Monitor for hyperglycemia - WHY?

  • Monitor for infection – WHY?

  • TAPER systemic steroids carefully during transfer to inhaled

  • Use decongestants/bronchodilators before steroids

  • Rinse mouth after using inhaler

  • Continue to use 2-3 weeks for effectiveness

Inhaler Use

• Shake inhaler. Hold inhaler with the mouthpiece down. Place lips around the mouthpiece so a tight seal is formed.

• While inhaling slowly through the mouth, press down on the inhaler one time

• Keep breathing in slowly and as deeply as possible

• Hold breath 10 – 20 seconds

• Take inhaler out of the mouth. If possible, hold breath while counting slowly to 10 to allow the medicine to reach deep into the lungs

• Pucker lips and breathe out slowly through mouth

• using inhaled, quick-relief medicine (bets-agonists), wait 1 minute before taking next puff of same med, if different med wait 5 minutes.

• Put cap back on the mouthpiece and make sure it is firmly closed

• After using the inhaler, rinse mouth with water, gargle, and spit. Instruct patient not to swallow the water. This helps reduce side effects from the medicine.

• Rinse the mouthpiece and cap in warm water.

Leukotriene modifiers (“luk” – leukotrienes)

• Indication: Prophylaxis and chronic tx of bronchial asthma

• Use: Long-term tx of asthma, prevent acute asthma attacks induced by allergens, exercise, cold air, hyperventilation, irritants, NSAIDS

• Action: Selectively and competitively blocks or antagonize receptors for the production of leukotrienes

• Contraindications: Cautious use in hepatic or renal impairment, pregnancy and lactation

• Prototypes: montelukast (Singulair), zafirlukast (Accolate)

• Pharmacokinetics: rapidly absorbed from GI tract, extensively metabolized in liver and primarily excreted in feces

• Route: PO, recommend taking in evenings

• Adverse effects: HA, dizziness, myalgia, N, V, D, abdominal pain, elevated liver enzyme, generalized pain, suicidal behaviors/thoughts, SJS, vasculitis, drug-induced hepatitis (women)

• Interactions

• Drug-drug interactions:

  • Propranolol, theophylline, terfenadine or warfarin

  • Calcium channel blockers, cyclosporine, or aspirin

• Nursing interventions:

• Monitor temperature, monitor liver and renal function, evaluate abdominal function, give on empty stomach either 1 hr before meals or 2 hours after meals, AVOID aspirin, Is NOT a rescue medication

Immunosuppressant Monoclonal Antibodies

• Indications: adjunctive therapy for moderate to severe persistent allergic asthma

• Action: inhibits IgE binding to IgE receptors on mast cells and basophils. Limits the activation and release of mediators in the early and late phases of the allergic response

• Contraindications: known allergy

• Prototypes: omalizumab (Xolar)

• Route: Sub-Q

• Adverse effects: anaphylaxis (BBW), local reactions, HA, N, fatigue

Mast cell stabilizer

• Prevent release of bronchoconstrictive and inflammatory substances in response to allergens, other stimuli

• Use: prophylaxis of acute asthma in mild, persistent asthma, NOT effective in acute bronchospasm or status asthmaticus

Respiratory Patient Teaching

• Use and teach measures to prevent or relieve bronchoconstriction

• Use and teach measures to prevent respiratory disease

• Use and teach measures to promote optimal air exchange

• Use and teach patient/family how perform objective symptom monitoring – peak flow meter

• Use mechanical measures for removing excessive secretions and preventing their retention. Effective measures include coughing, deep breathing, percussion, postural drainage, increase intake

• Help pt identify and avoid exposure to conditions that precipitate bronchoconstriction

• Identify early signs of difficulty, increased need for beta-adrenergic agonists, activity, etc.

Nursing Interventions

• Monitor the PEFR when indicated

• Assist patients with moderate to severe asthma in obtaining meters and learning to measure PEFR. Patients with decreased PEFR need treatment to prevent acute, severe respiratory distress.

• Assist patients and at least one family member in developing an action plan to identify the correct action to manage acute attacks of bronchoconstriction, including when to seek emergency care.

• Try to prevent or reduce anxiety, which aggravate bronchospasms.

• Encourage smoking, vaping, huffing cessation – provide resources and assistance

Lung Surfactants

• Indication: Rescue treatment of infants who have developed RDS

• Action: Replace the surfactant

• Contraindications: None since it is an emergency drug

• Prototypes: beractant (Survanta)

• Phamacokinetics: Acts immediately upon instillation, metabolized in the lungs

• Route: Tracheal installation via endotracheal tube

• Adverse effects: Patent ductus arteriosus, hypotension, intraventricular hemorrhage, pneumothorax, pulmonary air leak, hyperbilirubinemia and sepsis

Lung Surfactants Nursing interventions:

• Monitor patient continuously

• Evaluate ABGs and oxygen saturation

• Monitor temperature and complete blood count (CBC)

• Suction patient immediately before administration and then not for two hours after administration

• Monitor for adverse effects