Lecture V

Question 1

M1 Receptor

Answer 1

Activates Myenteric Plexus

Question 2

M2 Receptor

Answer 2

Decreases Heart rate and contraction

Question 3

M3 Receptor

Answer 3

• Contracts circular ciliary muscle (Pupillary constriction)
• Contracts bronchiolar muscle
• Contracts GI smooth muslce
• Contracts bladder detrusor muscle

Stimulates GI secretions, eccrine sweat glands, tear glands, salivary glands

M3 dry your patient up

Question 4

Nn Receptor

Answer 4

On the membrane of post ganglionic cells of both sympathetic and parasympathetic

Question 5

Nm Receptor

Answer 5

On the membranes of skeletal muscles.

Question 6

Nicotine

Answer 6

Nicotinic Receptor Agonist

• Selective for Nn receptor
• Limited to preparations for smoking cessation

Question 7

Succinylcholine

Answer 7

Blocks Nm receptor

*Muscle relaxant during intubation.

Method of Action: Prolonged depolarization of the membrane. Sits ont eh membrane and keeps it depolarized.

Question 8

Acetylcholine

Answer 8

• Binds to Nicotinic and Muscarinic receptors
• Rapidly hydrolyzed by acetyl- and plasma cholinesterases

No therapeutic use

Question 9

Methacholine

Answer 9

Muscarinic effects (on smooth muscle and heart)

• Longer duration of action than acetylcholine.
• Hydrolyzed more slowly by acetylcholinesterases
• Used to diagnose bronchail hyperactivity in patients with asthma
• Toxicity: Bronchiolar constriction
• Contraindication: Patients on beta blockers

Question 10

Carbachol

Answer 10

Muscarinic and nicotinic receptors

• Miotic agent in ophthamology (constriction) to reduce intra occular pressure in GLAUCOMA

Question 11

Bethanechol

Answer 11

Muscarinic selectivity

*Less CV Effects (little M2 activity)

Uses: Urinary retention

Toxicity: Bradycardia, bronchoconstriction

Contraindications: asthma bradycardia

Question 12

Muscarine

Answer 12

Highly selective for muscarinic

Toxic

Question 13

Pilocarpine

Answer 13

Muscarinic only

*Crosses the BBB

Uses: Problems of dry mouth, glaucoma

*Hypotension, Slowed AV conduction, excessive salivation

Question 14

Neostigmine

Answer 14

Poor penetration of BBB (Nm receptors)

Uses: Myasthenia gravis, reversal of non-depolarizing neuromuscular blockade

Toxicity: Excess

Contraindication: Intestinal obstruction (promotes gut motility)

Question 15

Edrophonium

Answer 15

Nm receptor activation

*Rapid onset, short duration

Uses: myasthenia gravis (too much or too little Ach inhibitor. Inhibits the cholinesterases so if the patient gets a little bit better it is due to the disease progression, if it gets worse, it is disease progression

Toxicity: Bradycardia

Contraindications: intestinal block

Question 16

Physostigmine

Answer 16

CROSSES BBB (inactivated by plasma cholinesterases)

Uses: Delerium with excess anticholinergic activation (prevents the degradation of Ach).

Question 17

Donepezil

Answer 17

Reversible inhibitor of Acetylcholinesterases in the CNS

Used in alzheimers disease

Question 18

Organophosphates

Answer 18

Irreversible Cholinesterase inhibitors

Found in Insecticides and nerve gases

Question 19

DUMBBELS

Answer 19

Diarrhea, Urination, Miosis, Bradychardia, Bronchorrhea, Emesis, Lacrimation, Salivation

Question 20

Treatment of severe organophosphate poisoning

Answer 20

1- Mechanical Ventilation
2- Suction of oral secretions
3- Atropine to protect from systemic muscarinic activation
4- Reactivation of the alkylphosphorylate acetylcholinesterase with 2-PAM.

Question 21

Echothiophate

Answer 21

Organophospate used to produce long term miosis in the treatment of open angle glaucoma

Question 22

Atropine

Answer 22

Muscarinic antagonist

Uses: relieve urgency and frequency of micturition, relieve hypermotility of colon and hypertonicity of small intestine, treatment of organophosphate poisoning, induce mydriasis, reverse bradycardia

Question 23

Scopolamine

Answer 23

Muscarinic antagonist

Uses: Preparation in surgical anesthesia to minimize secretions.

Treat nausea and vomiting associated with motion sickness and in chemotherapy

Question 24

Glycopyrrolate

Answer 24

Muscarinic antagonist

Uses: Prevent overstimulation of the gut during reversal of neuromuscular block

Question 25

Atropine Poisoning

Answer 25

Blind as a bat, mad as a hatter, red as a beet, hot as a hare, dry as a bone, the bowel and bladder lose their tone, and the heart runs alone.