Cholinergic Antagonists

Question 1

What is the mechanism of the cholinergic antagonists?

Answer 1

These drugs work by binding to the receptor, however, they do not perform a response

Question 2

What is the classification of M-choline receptors

Answer 2

Non-selective and these are divided in natural agents ( Atropine, and Platphylline ) and Synthetic and semisynthetic agents.
As for selective, there is a drug called Pirenzepine

Question 3

Explain the use of Atropine

Answer 3

Administered`: orally, IM, SC and topically

Non-selective (competes with all subtypes of M-choline receptors) causing antimuscarinic effects

Works in the peripheral and central nervous system

Question 4

What are the general side effects of Cholinergic antagonists

Answer 4

Dilated pupils resulting in photo­ phobia

Blurred vision
An increase intraocular pressure, an attack of glaucoma in someone with latent condition

Tachycardia no affects to blood pressure

Dry mouth/ dizziness

Constipation

Retention of urine as detrusor muscle is not fully contracted

flushed skin

increase in temperature

Question 5

Why would you prescribe cholinergic antagonist

Answer 5

eye diseases

Bradycardia

hyper salivation

gastric ulcer

acute pancreatitis

cholecytitis

billiary or renal colic

Enuresis

Premedication

Acute poisoning of cholinergic agonist

Question 6

What are the contraindications of cholinergic antagonist

Answer 6

Glaucoma

Tachycardia, taciarrhythmia

Atonia of the GI tract, achalasia, ulcerative colitis

Prostate hyperplasia, adenoma of
prostate

Hepatic insufficiency

Hyperthyroidism

High body temperature

Toxicosis of pregnancy

Cerebral pathology in children

Childhood/ old age

Question 7

What are the other cholinergic antagonist drugs , indications

Answer 7

Platphylline= Alkaloid, work on eye acts shortly, dilates blood vessels and lowers BP, treats BP

Pirenepine= this is a selective M1 cholinoblocker, inhibits gastric secretions, provided orally, IM, IV, provided in Zollinger-Ellison’s syndrome, prevents peptic ulcers caused by stress

Question 8

Define N-cholinoblockers

Answer 8

These are drugs which block the nicotinic receptor

Question 9

What are the 2 classifications of N-cholinergins

Answer 9

Quaternary amines and Tertiary amines

Question 10

Explain the use of Hexamethonium

Indications

Side effects

Answer 10

administered IM, IV, and orally, is poorly absorbed in the GI tract, does not penetrate CNS. duration of action is between 3-4 hours

This drugs works in both the sympathetic and parasympathetic nervous system.

What it does
Vasomotor effect; dilates blood vessels and bronchi so reducing blood pressure.
Stimulates contraction
decrease in sweat
decrease in bowel movement

Indication
Hypertensive emergence
Hypertension (rarely)
Controlled hypotension in surgeries Edema of the lungs
Edema of the brain
Bronchial asthma attack
Colic
Ulcer of the stomach (rarely).

Question 11

What are Myorelaxants (neuromuscular blockers)

Answer 11

These are cholinergic drugs which interfere with transmission of nervous impulses in the synapse of skeletal muscle causing relaxation