Nicotinic Antagonists

Question 1

Nicotine structure and how it works

Answer 1

Plant alkaloid that depolarizes ganglia and blocks them (persitent depolarization)

In high doses, essentially a blocker

At low doses, “positive” CNS effects

Question 2

Positive CNS effects of nicotine

Answer 2

Increase arousal, attnetion, and learning
Dependence producting
Most prevalent is on presyhnaptic receptor*****
Permissive action on NT in the nucleus accumbens (dopamine, glutamate)
Make presynaptic CNS notinic recpeotrs targets for smoking cessation (alpha 7s)

Question 3

How is nicotine ingested?

Answer 3

Accidental cigarrette ingetions in kids
Spill as insecticide
Smoker

Question 4

Ganglionic blockers effects on veins, arteries heart

Answer 4

Arteries - vasodilation and hypotension (normally under SNS)

Veins - dilation, decreases blood returning (SNS)

Heart - tachycardia (PNS)

Question 5

Iris/eye
GI
Bladder
Salivary glands
Sweat glands 

Affects of ganglionic blockers

Answer 5

Mydriasis (PNS)
Constipation (PNS)
Prevent filling (SNS)
Xerostomia (PNS)
Anyhydrosis (SNS)

Question 6

General affects of ganglionic blockers

Answer 6

Affect symp and para

Depress ALL autonomic functions

Inhibitors of nicotinic recpeotrs

Nonspecific

Question 7

NMJ blocker general effects

Answer 7

Devoid of central effects so still need anesthesia and analgesia

Used during surgicla and critical care to maintain paralysis

Question 8

NMJ blocker interactions

Answer 8

Aminoglycoside ABs - decrease Ach so additive effect

Volatile anesthetics - stabiliz NMJ which decreases signlaing - additive effect

Question 9

Classifications of NMJ blocks

Answer 9

Succinylcholine - depolarizing

Pancuronium - non-depolarizing

Question 10

NMJ blockers effects on muscles

Answer 10

Block nicotinic recpetors on striated muscles

Decrease O2 use and shivering
Facilitate mech ventilaiton

Need to use less anesthesia because the muscles are paralized

improves recovery time

Question 11

Atnagonists vs. agonists

Answer 11

Antagoists do not depolarize

Agonists depolarize so first fasciulations, then flaccid paralysis

Question 12

Curare

Answer 12

Non-depolarizing that blocks Ach receptors

Pancuronium is an example

Some release histamines

Can have ganglionic blocking effect

Question 13

Order of organ sensitivity for curare like and hwo t oovercome

Answer 13

Small muscles around eye and face
Neck and limbs
Intercostals
Diaphragm

Ovecome with AchE inhibitors

Question 14

Types of nondepolarizing blockrs

Answer 14

Isoquinolines - most release histamines (renal)

Steroids - do not release histamines but can be vagolytic (pancuronium - kidney and slower elimination)

Question 15

Succinylcholine

Answer 15

Depolarizing agent that blocks NMJ

First get opening, then desensitized and muscle repolarizes but unresponsive

Used for rapid intubation

Hydrolized by butyrylcholinesterases

Question 16

Succinylcholine other

Answer 16

Not reversible by AChE inhibitors

Can stimulate ganglion NT and muscarinic receptor in heart so arrythmias

Can get hyperkalemia

Question 17

Depolarizing NMJ blockers in general

Answer 17

Very rapid onset
SHort duration of acion
Some release histamine

Metabolized by butyrylcholinesterase (circulating levels determine duration of action)

Malignant hyperthermia can occur in patients with mutant plasma cholinesterase given succinylcholine

Question 18

CV Adverse effects of depolarizing NM blockers

Answer 18

CV - negative ionotropic and chronotropic effects at large doses

Arrythmias with halothane

Hypotension from ganglion NT

Venous pooling

Question 19

Hyperkalemia and GI, other effects of depolzriing NMJ blocker

Answer 19

Should not be used in patients with burns, soft tisue damage or NM dz

Increase intragastric pressure and risk of emesis and aspiration

Muscle pain

Increased salivary and bronchial secretion

May trigger malignant hyperthermia - use dantrolene

Question 20

Centrally acting muscle relaxers and uses

Answer 20

Work in spinal cord to increase inhibitory tone on reflex arc

Fibromyalgia, MS , cerebral palsy, stroke, chronic back pain and sprains

Question 21

Cyclobenzaprine and methocarbamol

Answer 21

High potential for abuse but better tha nplacebo

Question 22

Dantrolene

Answer 22

Works in muscles to decrease Ca levels attained during contration but decreasing Ca induced Ca release…less contracitons, less spasms, less pain

Not central acting

Question 23

Depressing polysynaptic spinal cord reflexes with

Answer 23

Centrally acting GABA agonists relieves pasticity and pain

Question 24

Drugs permeate tissues depending on

Answer 24

Charge present hydrophilicyt and lipophylicity