Bronchiodilators and other respiratory drugs Flashcards
What are the classes of bronchiodilators and respiratory drugs?
Bronchodilators
β-adrenergic agonists
Xanthine derivatives
Anticholinergics
Antileukotrienes
Corticosteroids
Explain what β-Agonists bronchiodilators are and what they do?
*Large group, sympathomimetics.
*Used during acute phase of asthmatic attacks.
*Quickly reduce airway constriction and restore normal airflow.
*Stimulate β2-adrenergic receptors throughout the lungs.
What are the three types of β-Agonists?
Nonselective adrenergics: Stimulate α, β1 (cardiac), and β2 (respiratory) receptors
* Example: epinephrine
Nonselective β-adrenergics: Stimulate both β1 and β2 receptors
* Example: metaproterenol (Alupent)
Selective β2 drugs: Stimulate only β2 receptors
* Example: albuterol (Proventil, others)
What is the β-Agonists mechanism of action?
Begins at the specific receptor stimulated, ends with the dilation of the airways.
Activation of β2 receptors activates cAMP,* which relaxes smooth muscles of the airway and results in bronchial dilation and increased airflow.
*cAMP = cyclic adenosine monophosphate.
What are the indications for β-Agonists?
1) Relief of bronchospasm related to asthma, bronchitis, and other pulmonary diseases.
2) Useful in treatment of acute attacks as well as prevention.
3) Used in hypotension and shock.
4) Used to produce uterine relaxation to prevent premature labor.
5) Hyperkalemia—stimulates potassium to shift into the cell.
What are the adverse effects of β-Agonists?
α-β (epinephrine)
β1 and β2 (metaproterenol)
β2 (albuterol)
α-β (epinephrine):
Insomnia, Restlessness, Anorexia, Vascular headache, Hyperglycemia, Tremor, Cardiac stimulation
β1 and β2 (metaproterenol):
Cardiac stimulation, Tremor, Anginal pain.
β2 (albuterol):
Hypotension OR hypertension, Vascular headache, Tremor.
What are some nursing interventions for respiratory drug therapy?
1) Encourage patients to take measures that promote a generally good state of health in order to prevent, relieve, or decrease symptoms of COPD.
2) Avoid exposure to conditions that precipitate bronchospasms (allergens, smoking, stress, air pollutants).
3) Adequate fluid intake.
4) Compliance with medical treatment.
5) Avoid excessive fatigue, heat, extremes in temperature, caffeine.
- Encourage patients to get prompt treatment for flu or other illnesses, and to get vaccinated against pneumonia or flu.
- Encourage patients to always check with their physician before taking any other medication, including OTCs.
6) Perform a thorough assessment before beginning therapy, including: Skin color; baseline vital signs; Respirations (should be between 12 and 24 breaths/min); Respiratory assessment, including PO2; Sputum production; Allergies; History of respiratory problems.
7) Other medications:
- Teach patients to take bronchodilators exactly prescribed.
- Ensure that patients know how to use inhalers and MDIs, and have the patients demonstrate use of devices.
- Monitor for adverse effects.
8) Monitor for therapeutic effects.
9) Decreased dyspnea; Decreased wheezing, restlessness, and anxiety; Improved respiratory patterns with return to normal rate and quality; Improved activity tolerance.
10) Decreased symptoms and increased ease of breathing.
What are some nursing implications for β-Agonist Derivatives?
1) Patients should take medications exactly as prescribed, with no omissions or double doses.
2) Patients should report insomnia, jitteriness, restlessness, palpitations, chest pain, or
any change in symptoms.
*Albuterol, if used too frequently, loses its β2-specific actions at larger doses.
*As a result, β1 receptors are stimulated, causing nausea, increased anxiety, palpitations, tremors, and increased heart rate.
Patient education for inhalers?
For any inhaler prescribed, ensure that the patient is able to self-administer the medication.
Provide demonstration and return demonstration.
Ensure the patient knows the correct time intervals for inhalers.
Provide a spacer if the patient has difficulty coordinating breathing with inhaler activation.
Ensure that patient knows how to keep track of the number of doses in the inhaler device.
What is the mechanism of action of anticholinergics?
Acetylcholine (ACh) causes bronchial constriction and narrowing of the airways. Anticholinergics bind to the ACh receptors, preventing ACh from binding.
Result: bronchoconstriction is prevented, airways dilate
Anticholinergics: ipratropium bromide (Atrovent) and tiotropium (Spiriva)
- Slow and prolonged action
- Used to prevent bronchoconstriction
*NOT used for acute asthma exacerbations!
What are the adverse effects of anticholinergics?
Dry mouth or throat
Nasal congestion
Heart palpitations
Gastrointestinal distress
Headache
Coughing
Anxiety
No known drug interactions
What are xanthine derivitive bronchiodilators?
Plant alkaloids: caffeine, theobromine, and theophylline.
Only theophylline is used as a bronchodilator.
Synthetic xanthines: aminophylline; dyphilline; oxtriphylline.
What are the mechanisms of action of Xanthine derivitives?
Increase levels of energy-producing cAMP. This is done competitively inhibiting phosphodiesterase (PDE), the enzyme that breaks down cAMP.
Result:↓cAMP levels, smooth muscle relaxation, bronchodilation, & increased airflow.
What are the drug effects of Xanthine drugs?
- Cause bronchodilation by relaxing smooth muscles of the airways.
- Result: relief of bronchospasm and greater airflow into and out of the lungs.
- Also cause CNS stimulation.
*Also cause cardiovascular stimulation: increased force of contraction and increased heart rate, resulting in increased cardiac output and increased blood flow to the kidneys (diuretic effect).
What are the Xanthine derivitive indications?
Dilation of airways in asthmas, chronic bronchitis, and emphysema.
Mild to moderate cases of acute asthma.
Adjunct drug in the management of COPD.
Not used as frequently due to potential for drug interactions and variables related to drug levels in the blood.
