Beta Adrenergic Agonists. Flashcards
What is a non-selective agonist?
A drug that can bind to beta-1 or beta-2 receptors.
What is the mode of action of isoproteronol?
It is a non-selective beta agonist.
What effects will isoproteronol have when it binds to beta-1 receptors?
Positive inotropic, dromotropic and chronotropic effects.
What are inotropic effects?
Effects that affect the strength of heart contraction.
What are dromotropic effects?
Effects that affect the speed of conduction in the heart.
What are chronotropic effects?
Effects that affect the heart rate.
What effects will isoproteronol have when it binds to beta-2 receptors?
Vasodilation.
Uterine relaxation.
Isoproteronol is used to treat what 2 conditions?
Bradycardia.
Heart block.
What are the side effects of isoproteronol?
Cardiac ischemia.
Arrhythmias.
Where do beta-1 receptors tend to be located?
In the heart.
Where do beta-2 receptors tend to be located?
In skeletal muscle.
What happens when beta-2 receptors in skeletal muscle are stimulated?
It leads to vasodilation.
What is the mode of action, therapeutic uses and sidea effects of dobutamine?
Affects beta-1 receptors in cardiac muscle.
Treats congestive heart failure.
Side effects. Increases AV conduction and leads to tolerance.
What happens when a drug increases tolerance?
If a drug is administered for a long time then the body down regulates receptors for that drug.
What is the major effect of dobutamine on the body?
It increases the muscular contractions of the heart without affecting the rhythm and this improves cardiac output.
Dobutamine is often given to what kind of patients?
Patients that suffer deficiencies in cardiac muscle.
Patients that suffer from congestive heart failure.
What is congestive heart failure?
When blood remains in the heart after contraction.
Bronchodilators will affect what kind of receptors?
Beta-2 receptors.
What are the 3 beta-2 agonists that act as bronchodilators?
Metaproteranol.
Terbutaline.
Salbutamol.
Which bronchodilator should not be given to animals with heart disease, hypertension or hyperthyroidism?
Terbutaline.
What is the mode of action of clenbuterol?
It is a beta-2 agonist that leads to bronchodilation.
Clenbuterol is given to what kind of animals?
Horses.
Ventipulmin.
Clenbuterol is banned to give to what kind of animals?
Food producing animals.
What is the mode of action of salmeterol?
It is a beta-2 agonist that leads to long lasting bronchodilation.
Salmeterol is given to treat what conditions?
It is given to animals with asthma to help them deal with any attacks.
What is the mode of action of isoxsuprine and what is it used for?
It is a beta-2 agonist.
It is used to treat laminitis/navicular in horses.
How does isoxsuprine treat laminitis/navicular in horses?
It causes vasodilation in skeletal muscle blood vessels and this means more blood flows to the extremities.
What is the mode of action of ritodrine and what is it used for?
It is a beta-2 agonist.
It relaxes the uterus and is used to arrest premature labour.
What is the mode of action of ractopamine and what is it used for?
It is a beta-2 agonist.
It increases the leanness of muscle in food animals.
Do you need to withdraw ractopamine from food animals before they are sent to slaughter?
No.
What are the side effects of ractopamine?
Bloat.
Anorexia.
What are the common side effects of beta-2 agonists?
Skeletal muscle tremors.
Pulmonary oedema.
Tachycardia.
Tolerance.
What are the therapeutic uses of beta-1 agonists?
They are used to treat congestive heart failure.
What are the therapeutic uses of beta-2 agonists?
Treatment of bronchial asthma.
Treatment of premature labour.
Treatment of navicular disease.
Use as a re-partitioning agent.
