Cholinergic agents.ppt.....................

Cholerngic drugs

1. Cholinergic Agents

2. Cholinergic Agents
Drugs that stimulate the
parasympathetic nervous system (PSNS)
The PSNS is the opposing system to
the SNS

3. Cholinergic Agents
Also known as
cholinergic agonists
or
parasympathomimetics

4. Cholinergic Agents
Mimic the effects of the PSNS
neurotransmitter
Acetylcholine (ACh)

5. Direct-acting (agonist)
Bind to cholinergic receptors, causing
stimulation
Indirect-acting
Inhibit the enzyme “cholinesterase”
Result: more ACh is available at the
receptors
Cholinergic Agents

6. Cholinergic Agents

7. Cholinergic Receptors
Two types, determined by:
Location
Action once stimulated
Nicotinic receptors and Muscarinic receptors

8. Nicotinic Receptors
Located in the ganglia of both the
PSNS and SNS
Named “nicotinic” because can be
stimulated by the alkaloid nicotine

9. Muscarinic Receptors
Located postsynaptically:
Smooth muscle
Cardiac muscle
Glands of parasympathetic fibers
Effector organs of cholinergic sympathetic fibers
(Sweat gland)
Named “Muscarinic” because can be
stimulated by the alkaloid Muscarine

10. Drug Effects of Cholinergic
Agents
Stimulate pupil
Constriction (miosis)
Reduced intraocular pressure
Cardiovascular effects
Decreased heart rate
Vasodilation (not direct but through release of
(EDRF)
Respiratory effects
Bronchial constriction, narrowed airways

11. Drug Effects of Cholinergic
Agents
Stimulate intestine and bladder
Increased gastrointestinal motility
Increased gastric secretions
Increased urinary frequency
Increased salivation and sweating

12. Bethenechol
It is not hydrolyzed by acetylcholinestrase
It lacks nicotinic activity
Its major action on smooth muscles of GIT
and urinary bladder
Mostly used for the urologic conditions

13. Carbachol
Having both muscarinic and nicotinic actions
Having long duration of action
Produce effects on CVS & GIT
Mostly it is used for opthalmic coditions

14. Pilocarpine
Tertiary amine and stable to hydrolysis by
acetylcholineserase.
Having muscarinic activity
It is mostly used for eye problems
Acute glaucoma
Sjogren syndrome

15. Side Effects of Cholinergic Agents
“SLUDGE”
Salivation
Lacrimation
Urinary incontinence
Diarrhea
Gastrointestinal cramps
Emesis