Respiratory Drugs Flashcards
What are 7 categories of respiratory drugs?
- Bronchodilators and anti-inflammatory drugs
- Antitussives
- Mucokinetics
- Expectorants
- Decongestants
- Drugs for pulmonary edema
- Antifoaming agents
What are three categories of bronchodilators?
- Beta adrenergic agonists
- Methylxanthine derivatives
- Anticholinergics
What is the non-selective B-agonist that is the DOC for treating life-threatening bronchospasm?
Epinephrine!
What are some fun facts about Epinephrine?
- DOC for emergency treatment of life-threatening bronchospasm.
- Give IV or IM for a single treatment.
- Short acting (>1 hour)
- Not for long-term use
- Adverse effects are due to stimulation of alpha and beta adrenergic receptors.
What is another non-selective B-agonist (aside from Epinephrine) that is used as a bronchodilator?
Isoproterenol
How is Isoproterenol administered and what are its adverse effects?
Isoproterenol is administered by inhalation or injection. Adverse effects are due to stimulation of B1 and B2 receptors.
What are some fun facts about B2-Selective Agonists?
- More selective in stimulating B2 than B1.
- Stimulation of B2 causes bronchodilation and stabilization of mast cells and also increases mucociliary clearance.
- Continuous use can result in tolerance.
What are some effects that are caused by B2-selective agonists?
Can cause cardiac stimulation, vasodilation, uterine relaxation, hyperglycemia, and may cause moderate hypokalemia by stimulating Na/K ATPase.
What are the uses for B2-selective agonists?
Bronchodilators that are used to treat and prevent acute bronchoconstriction due to bronchial asthma in cats or COPD (chronic obstructive pulmonary disease) in horses.
What are the adverse effects of B2-selective agonists?
- Sinus tachycardia and premature ventricular contractions.
- CNS stimulation
- Tremors/muscle cramps
- Hyperglycemia
- Moderate hypokalemia
- Uterine relaxation
Clenbuterol, a B2-selective agonist, has what kind of effect?
It has anabolic effect and large doses cause muscle twitching and hyperthermia.
What are some fun facts about Terbutaline?
- Duration of action: 6-8 hrs
- Administered orally or by injection in small animals.
- Administered as an injection in horses; no oral absorption.
What are some fun facts about Metaproterenol?
- DOA: 4 hours
- Administered orally as tablets
What are some fun facts about Albuterol?
- Administered orally and by inhalation in cats and horses.
- Aerosol is approved for use in horses.
T/F: Clenbuterol is safe to use in food animals.
False! It is illegal to use Clenbuterol in food animals.
What two B2-selective agonists are not used in animals?
Salmeterol and Formoterol
What four drugs are classified as Methylxanthine Derivatives?
- Theophylline
- Aminophylline
- Caffeine
- Theobromine
What is the MOA for methylxanthine derivatives?
Antagonism of adenosine receptors, inhibition of phosphodiesterase, acting on intracellular calcium, inhibition of degranulation of mast cells and inhibition of prostaglandins.
How are methylxanthine derivatives administered, dosed and metabolized?
- They are administered orally and parenterally.
- Relatively large Vd in dogs, horses and cattle, but lower in cats.
- Metabolized by methylation in the liver.
How long do methylxanthine derivatives work?
Several hours
What are the pharmacological effects of methylxanthine derivatives?
- CNS stimulation
- Respiratory: bronchodilation, anti-inflammatory of microvascular leakage, stimulating mucociliary clearance and improved breathing.
- Cardiovascular: stimulation of myocardial contractility, increasing heart rate and systolic pressure, and vasodilation.
- Stimulation of skeletal muscles/
What are some therapeutic uses of methylxanthine derivatives?
Bronchoconstriction, bronchial asthma, COPD
Aminophylline is used in treatment of what?
Severe cases of congestive heart failure and anaphylaxis.
What are some adverse effects of methylxanthine derivatives?
- CNS stimulation
- Salivation, nausea, vomiting
- Diuresis
- Tachycardia, tachyarrhythmias, and hypotension.
What are three contraindications/precautions for methylxanthine derivatives?
- Cardiac disease
- Peptic ulcer disease
- Seizure disorder
What are two drug interactions of methylxanthine derivatives?
- Cardiac stimulants (tachycardia)
2. Inhalation anesthetics (hypotension)
What are three anticholinergic drugs?
- Ipratropium
- Atropine
- Glycopyrrolate
What do anticholinergics do to the PNS and SNS?
They block the PNS, so they will cause bronchodilation but also probably other SNS signs.