Adrenergic Agonist

Question 1

What are adrenergic drugs and how do they act

Answer 1

These drugs affect the receptors of epinephrine and norepinephrine. They can be direct or indirect such as those that block the action of the neurotransmission or increase the action

Question 2

What is the neurotransmitter associated with Adrenergic neuron

Answer 2

Norepinephrine

Question 3

What are the classification of adrenergic receptors

Answer 3

a1 and a2 and b

They interact with either epinephrine, norepinephrine, and isoproterenol.

Question 4

What are a1 and a2 receptors

Answer 4

a1 receptor located in the postsynaptic membrane
This causes vasoconstriction, hypertension, increased closure of the internal sphincter of the bladder, dilated pupils

a2 these are found in the presynaptic membrane.
A portion of the released norepinephrine “circles back” and reacts with α2 receptors on the neuronal membrane The stimulation of the α2 receptor causes feedback inhibition of the ongoing release of norepinephrine from the stimulated adrenergic neuron. This reduces thus stops norepinephrine from being released. to a1 and also inhibits acetylcholine release

The function is that it inhibits norepinephrine, acetylcholine and insulin release

Question 5

What are beta receptors

Answer 5

These have a high affinity to isoproterenol compared to the catecholamines
B-recpetors are subdivided into 3 categories B1 B2 B3.
B1 has an equal affinity to both B1 and B2 where as B2 has a higher affinity to epinephrine compared to norepinephrine

B1 caused tachycardia, increased liplysis, increased myocardial contractility and increase renin

B2  Dilation of bronchi, causes Vasodilation, Decreased peripheral
resistance, Bronchodilation
Increased muscle
and liver glycogenolysis,
Increased release of glucagon, 
Relaxed uterine smooth muscle

Question 6

Why will you give a-adrenergic agonist

Answer 6

(Anaphylactic) shock, collapse, prolonged local anesthesia, rhinitis, glaucoma, diagnostic of eye disease, conjunctivitis, bronchial asthma, bradycardia, pupil dilation, euresis, myasthenia , pathological narcolepsia

Question 7

Why will you give b-adrenergic agonist

Answer 7

bronchial asthma, spasm or bronchi, heart block, bradycardia, danger of pregnancy interruption

Question 8

List the a-adrenergic agonist

Answer 8

adrenaline provided SC,IM,IV works on both a and b receptors direct acting

Phenylephrine non-catecholamine works on a1 receptor. provided SC,IM,IV, Topically, may be provided orally

Question 9

What are the general side effects of adrenaline/ a-adrenergic agonist

Answer 9

Insomnia, anxiety, restlessness, tachycardia, palpitations, hypertension, rashes on skin, tolerance and tachyphylaxisis, drug dependence

Question 10

What drug works on B-adrenergic agonist

Answer 10

Salbutamol works on B2 receptors only works on the bronchi

Dobutamine works on B1 receptors, it increased cardiac output, provided IV, used for acute heart insufficiency and cardiogenic shock