Oral: NMB Reversal

Question 1

Class: NEOSTIGMINE and EDROPHONIUM and PYRIDOSTIGMINE

Answer 1

Acetylcholinesterase inhibitor

Question 2

MOA: NEOSTIGMINE and EDROPHONIUM and PYRIDOSTIGMINE

Answer 2

Irreversibly binds to inhibits AChE = inc Ach in synaptic clef
Inhibits hydrolysis of Ach – inhibits breakdown = inc Ach at NMJ
Allows Ach to reoccupy site

Question 3

PK: NEOSTIGMINE

Answer 3

Vd L/kg: 0.8
Onset: 3 min (HIGHEST potency – FAST onset)
Peak = 7 – 10 min
DOA: 45 – 90 min
Hepatic metab + hydrolyzed by plasma esterases
Elim: Renal – 50% unchanged, 50% hydrolyzed by plasma esterases + liver
E1/2t: 1.5 hrs

Question 4

SE: NEOSTIGMINE and EDROPHONIUM and PYRIDOSTIGMINE

Answer 4

Pulm: bronchoconstriction
CV: dec HR d/t vagal stim - dec BP SVR
S - inc salivation, sweating
L – lacrimation (tears) 
U – urination
D – defecation (inc peristalsis) 
G - inc gastric secretions, n/v

Question 5

CI: NEOSTIGMINE

Answer 5

Drug specific = dec efficacy w/ verapamil

Question 6

CI: NEOSTIGMINE and EDROPHONIUM and PYRIDOSTIGMINE and PHYSOSTIGMINE

Answer 6

ALL anticholinesterases: prolong the doa of SUX

ALL: use extreme caution w/
rate dep CV dz, asthma, bronchospastic dz, CAD, pre-existing dec bp + hr,
RF = dec plasma clearance + inc doa

Question 7

Dose: NEOSTIGMINE

Answer 7

0.04 – 0.07 mg/kg

+ 0.01mg/kg GLYCO

Question 8

PK: EDROPHONIUM

Answer 8

Vd L/kg: 1.4
Onset: 1 min (LEAST potency – FASTEST onset) 
Peak = 1 – 2 min
DOA: 45 – 60 min
Hepatic metab
Elim: Renal – 75% unchanged
E1/2t: 2 hrs

Question 9

Dose: EDROPHONIUM

Answer 9

0.5 – 1 mg/kg

+ 0.02 mg/kg ATROPINE

Question 10

PK: PYRIDOSTIGMINE

Answer 10

NOT lipid soluble
Vd L/kg: 1.1
Onset: 15 min (INT potency – SLOWEST onset)
DOA: 2 hr
Hepatic metab 
Elim: Renal – 75% unchanged
E1/2t: 2 hrs

Question 11

CI: PYRIDOSTIGMINE

Answer 11

Hypersensitivity, bromide allergy, GI or GU obstruction

Question 12

Dose: PYRIDOSTIGMINE

Answer 12

NMB reversal: 100 – 300 mcg/kg
Max dose: 350 mcg/kg
+ atropine 15 – 20 mcg/kg OR glyco 10 mcg/kg

Question 13

Class: PHYSOSTIGMINE

Answer 13

Centrally acting anticholinesterase
Anticholinesterase reversal!
Add to Anticholinergic slide deck!!

Question 14

MOA: PHYSOSTIGMINE

Answer 14

Reversible competitive inhibitor of AChE = dec Ach metabolism + inc Ach levels at synaptic cleft -> inc transmission of impulses across the NMJ and prolongs the periph + CNS effects of ACh

Question 15

PK: PHYSOSTIGMINE

Answer 15

Lipid soluble
Vd L/kg: 0.7-1.4
Onset: 5 min 
DOA: 0.5 - 5 hr
Hydrolyzed by cholinesterases 
Elim: Minimal renal elimination 
E1/2t: 15 - 40 min

Question 16

SE: PHYSOSTIGMINE

Answer 16

1. dec HR + BP
2. inc secretions, n/v, inc peristaltic activity
3. bronchoconstriction
4. cholinergic crisis

Question 17

CI: PHYSOSTIGMINE

Answer 17

Mechanical intestinal or urinary obstruction

Contaminant choline ester
or
depolarizing neuromuscular blocker use
+ CAD

Question 18

Dose: PHYSOSTIGMINE

Answer 18

15 – 60 mcg/kg = 0.5 mg/kg q 1 – 2 hrs