Muscarinic
WET
Promuscarinics
Nicotinic
Trt of
cholinergic
syndrome
Anticholingergic / cholinergic syndrome
Defecation
Urination
Meiosis
Bronchorrhoea
Bradycardia
Emesis
Lacrimation
Salivation
Mushrooms (inocybe, clitocybe), OP’s, funnel web venom, betel nut, pilocarpine
Fasciculation, tremor, weakness, resp muscle paralysis, incr HR, incr BP; delayed onset weakness nad
neurotoxicity
Staff protection: gloves, clothing, masks, eye shields, resp filter if INH
Decontamination: remove clothing, wash with soap and water (manage off run), use chlorine bleach; charcoal
may decr toxicity
ABC: start at same time as decontamination; sux may cause paralysis for hrs-days; relative resistance to nondepolarising agents (due to incr Ach at receptor);
atracurium is good alternative; high flow O2;
diazepam (prevents seizures, may improve survival, reduces resp depression; give 5-10mg IV)
Anti-muscarinic
Antidotes:
Atropine: competitive muscarinic antagonist; reverses cholinergic Sx (non-CNS); no effect on muscle
weakness (nicotinic)
Indications: wheeze, cough, decr HR, decr BP, miosis, sweating, decr AE
Dose: 1-2mg (0.05mg/kg in children) Q5min until drying of secretions, resolution of HR and good AE;
may need >2-5mg/hr
Glycopyrolate: reverses cholinergic Sx (not CNS); use if atropine run out
Dose: 0.05mg/kg IV
Pralidoxime: best given within few hrs (before aging), can be given up to 36hrs; onset 10-40mins; reverses
some of CNS toxicity (may initially worsen Paralysis, but should reverse NM blockade); hasn’t
been shown to improve survival or decr need for ETT; may worsen carbamate poisoning
Indications: severe Sx, resistant to atropine
Dose: 1-2g slow IV in 200ml 5% dex (25-50mg/kg in children)  INF 1g/hr (10-20mg/kg/hr) for 24-48hrs
Endpoint: cholinesterase >10%, EMG normalises
FFP: increases plasma pseudocholinesterase levels; give 2iu/day until atropine no longer needed
Onset 30-120mins  resolve in 6-8hrs if mild, 24-60hrs if mod, 7eral days if severe
M1
Red as a beat
Hot as a hare  MOF, rhabdo
Dry as a bone, urinary retention, constipation, absent bowel sounds, decr gastric motility (may delay onset)
Blind as a bat, mydriasis (often delayed 12-24hrs), cycloplegia
Mad as a hatter, confusion, visual hallucinations, seizures, dysarthria
H1
Incr HR, hypotension, muscle weakness, postural hypotension, resp paralysis, sedation
Antimuscarinics
Some have Na and K channel blocking
Benztropine (trt of EPSE), antiParkinson drugs
Buscopan
Atropine, hyoscine, scopolamine, Cyproheptadine, dothiepin, glycopyrolate
Antihistamines (most common OD causing toxicity)
TCA, SSRI’s, antispasmodics (eg. Carbamazepine)
Antipsychotics (eg. Olanzapine, clozapine, phenothiazines, chlorprom)
Trt of anticholinergic
syndrome
Procainamide, quinidine
Oxybutynin
Ipratropium, tiotropium
Trumpet lily, Jimsonweed, amanita muscaria, Belladonna, mandrake
Decontamination: Charcoal: may be effective >1hr after due to delayed gastric emptying; MDAC may be used
with caution
Supportive: Supportive, benzo’s (avoid haloperidol), trt hyperT; NaHCO3 if wide complex tachycardia
Physostigmine
Antidote:
(acetylcholinesterase inhibitor)
Indication: if severe CNS toxicity (severe agitation/delirium) esp if not responding to benzos / requiring
physical restraint, GHB OD, amanita muscaria
0.1mg
Dose:
(0.02mg/kg) IV  rpt Q5min to 2mg (0.5mg/kg) max; on cardiac monitor
CI: co-ingestions with Na blockers, mechanical obstruction of GI/GU tract; QRS >100, PR >200, RAD
Relative: asthma, PVD, gangrene, IHD, glaucoma
SE: Sx of cholinergic syndrome; seizures, bradycardia and conduction delays with rapid admin
Disposition: observe all at least 4hrs