Neostigmine
Chemical
Quaternary amine
Use
Reversal NDMR
Tx MG
Urinary retention
Paralytic Ileus
Presentation
Clear soln
2.5mg/ml
Tablet 15-30mg
Dose
0.05mg/kg
Low dose = muscarinic effects
High dose = nicotinic effects
Route
PO/IV
Onset
7-10min
DoA (Duration)
50min
MoA
Reversible binds AChE
Covalent bond
Hydrolses enzyme at slow rate
[ACh]
Hydrolysis regenerates enzyme
PD
NMJ
↑[ACh] @NMJ
Overcomes NDMR
ACh can bind nAChR and allow muscle contraction
CVS
Bradycardia
↓CO
↑Conduction time
RESP
Bronchospasm, ↑secretions
CNS
Nil cannot cross BBB
GI
Diarrhoea, ↑secretions
RENAL
Incontinence
ANS
DUMB BELLS
Diarrhoea, Urinarytion, Myosis, ‘deadly Bs’ Bronchoconstriction & Bradycardia, Emesis, Lacrimation, Lethargy, Salivation
Mx AE
Atropine,
Glycopyrrolate
PK
A
Poor, 1% OBA
D
10% PPB
Highly ionised
0.5L/kg
M
Plasma esterases
E
65% urine
Renal unchanged
Renal failure = prolonged DoA
Adverse Effects
DUMB BELLS
- Analogue of Neostigmine
- ¼ potency
- MoA Neostigmine
- Slower onset 16mins (so not used to reverse NDMR)
- DoA 6hrs (used for MG)