parasympathetic activation/inhibition

Question 1

parasympathetic activation effects the following organs:

Answer 1

GI: increase digestion, motility
bladder: wall contraction, relax sphincter
eye: miosis, ciliary muscle contraction (accommodation)
lung: smooth muscle contraction
heart: decrease HR, contractility
lacrimal gland: stimulate tears 
salivary gland: watery secretion
uterus: contract
penis/clitoris: erection/engorgement

Question 2

cholinergic excess is caused by

Answer 2

cholinesterase inhibitor poisioning:
organophosphates - irreversibly inhibit acetylcholinesterase (insecticide, farmers)
indirect cholinergic agonists:-stigmine, donepezil, edrophonium

Question 3

is cholinergic excess the same as excess parasympathetic activation?

Answer 3

No!
muscarinic receptor located on sweat glands and nicotinic receptor on adrenal medulla (sympathetic nerve fibers)
nicotinic receptor on skeletal muscle (somatic nerve)

Question 4

symptoms of cholinergic excess

Answer 4

DUMBBELSS (leaky state)
Diarrhea
Urination
Miosis
Bronchospasm
Bradycardia
Excitation of skeletal muscle (nicotinic R, somatic nerve) + CNS (nicotinic R)
Lacrimation
Sweating (sweat glands controlled by sympathetic NS, muscarinic R)
Salivation

Question 5

antidote for cholinergic excess

Answer 5

decrease stimulation of excess Ach on muscarinic receptors

atropine (competitive inhibitor of muscarinic receptor) + pralidoxime (regenerates Ach if given early)

Question 6

cause of myasthenia gravis

Answer 6

antibodies to Ach R

Question 7

ptosis + diplopia worsens throughout day is:

Answer 7

myasthenia gravis

Question 8

diagnosis of myasthenia gravis

Answer 8

edrophonium (tensilon test - short acting inhibitor of acetylcholinesterase)

Question 9

associated symptoms with myasthenia gravis

Answer 9

thymus pathology:
50%: thymic hyperplasia
20%: thymic atrophy
15%: tumor (thymoma)

Question 10

complication of myasthenia gravis

Answer 10

myasthenic crisis: rapidly progressing weakness of respiratory myscles

Question 11

treatment of myasthenia gravis

Answer 11

indirect cholinergic agonist: neostigmine, pyridostigmine
immunotherapy: CS, azathioprine, cyclosporine
thymectomy
plasmaphoresis: remove Abs

Question 12

indirect cholinergic agonists used in alzheimer’s disease

Answer 12

↓ cholinetransferase →↓ Ach made → inhibit acetylcholinesterase:
donepezil
galantamine
rivistigmine

Question 13

can anticholinergic or antimuscarinic or parasympathetic inhibition be used interchangeably?

Answer 13

Yes - even though:

anticholinergic: block Ach effect
antimuscarinic: block muscarinic R

Question 14

anticholinergics used to treat urge type incontinence

Answer 14

On The Darn Toilet
Oxybutynin
Tolterodine
Darifenacin and solifenacin
Trospium

Question 15

other medications with anticholinergic side effects

Answer 15

first generation H1 blockers: diphenhydramine, doxylamine, chlorpheniramine
anti-psychotics (neuroleptic): thioridazine, chlorpromazine, olanzapine, clozapine
TCA - dry mouth
amantadine

Question 16

elderly with delerium…consider:

Answer 16

anticholinergic effects of a drug

Question 17

symptoms of parasympathetic inhibition (anticholinergic/antimuscarinic effects of drugs - like atropine)

Answer 17

Hot as a Hare: hyperpyrexia (not sweating - inhibit muscarinic R)
Red as a Beet: vasodilation - flushed
Blind as a Bat: cyloplegia (no accommodation), mydriasis
Dry as a Bone: no salvation
Mad as a Hatter: agitation, delerium (ELDERLY)
Bloated as a Toad - constipated, urinary retention
+ tachycardia

Question 18

what drug should be used to treat urinary retention due to anticholinergic effects of a neuroleptic?

Answer 18

cholinergic agonist - bethanechol