Cholinesterase Inhibitors

Question 1

Special actions

Answer 1

• skeletal muscle stimulation (therapeutic dose)
• skeletal muscle paralysis (toxic dose)
• bronchoconstriction

Question 2

Toxic effects: SLUDGE acronym

Answer 2

Salivation
Lacrimation
Urination
Defecation
GI distress
Emesis

Question 3

Acute cholinesterase inhibitor poisoning: treatment procedure

Answer 3

1. administer high doses of atropine (2-4mg IV -> 2mg IM)
2. administer pralidoxime to reactivate enzyme (only w/ organophosphates)
3. symptomatic treatment as needed (Diazepam for seizures)

Question 4

Tensilon test

Answer 4

• MG diagnosis
• 2-8mg edrophonium
• pos for MG: improvement of muscle strength
• pos for toxic chol inh: decrease in muscle strength

Question 5

Glaucoma treatment

Answer 5

• contract ciliary muscle
• tension on trabecular meshwork
• increase aqueous humor outflow (Schlemm)

Question 6

Alzheimer’s disease treatment

Answer 6

• raise acetylcholine levels

- reverse cholinergic deficit

Question 7

Edrophonium (Tensilon)

Answer 7

• reversible cholinesterase inhibitor
• quaternary ammonium salt compound (no CNS)
• short acting (<10 min)

main use: MG diagnosis (Tensilon test)

Question 8

Neostigmine (Prostigmin)

Answer 8

• reversible cholinesterase inhibitor
• quaternary ammonium salt compound (no CNS)
• longer acting

main use: MG treatment

Question 9

Pyridostigmine (Mestinon)

Answer 9

• reversible cholinesterase inhibitor
• quaternary ammonium salt compound (no CNS)
• longer acting

main use: MG treatment
miltary use: nerve agent prophylaxis

Question 10

Physostigmine/eserine (Antilirium)

Answer 10

• reversible cholinesterase inhibitor
• nonquaternary (yes CNS)

main use: atropine (or other antimuscarinics) poisoning

-disfavor in tricyclic antidepressant OD treatment

Question 11

Parathion (poisoning)

Answer 11

• organophosphate insecticide
• oxidized to paroxone
• absorbed through skin

treat with: atropine, pralidoxime

Question 12

Malathion (poisoning)

Answer 12

• organophosphate insecticide
• absorbed through skin
• oxidized to maloxone

treat with: atropine, pralidoxime

Question 13

Carbaryl (poisoning)

Answer 13

• carbamate insecticide
• not absorbed through skin

treat with: atropine

-pralidoxime not useful in treatment

Question 14

DFP/Isoflurophate (Sarin) (poisoning)

Answer 14

• nerve gas
• irreversible cholinesterase inhibitors

treat with: atropine, pralidoxime

therapeutic use: glaucoma

Question 15

Pralidoxime/2-PAM (Protopam)

Answer 15

• cholinesterase reactivator (binds inhibitory phosphate)
• organophosphate poisoning antidote
• must be used within 2 hours following exposure
• does not work with carbamate poisoning (carbaryl)