Atropine Flashcards
Class
- Parasympatholytic
2. Anticholinergic Agent
Action
- Atropine is a competitive inhibitor of acetylcholine @
muscarinic receptor sites. - The increase of sympathetic activity seen with atropine
administration is due to the drug’s parasympatholytic
effects. - In the setting of symptomatic bradycardias, atropine
decreases vagal effects on the heart resulting in
increased chronotropy & dromotropy (with little or no
inotropic effects). - It is used in cholinergic exposures as a direct antidote
for the poison.
Indications
- Symptomatic Bradycardias
- Pre-intubation in children >1 month of age
- Poisoning w/
- oganophosphates, carbamates, mushrooms, nerve
gas, other cholinergic agents
- oganophosphates, carbamates, mushrooms, nerve
Contraindications
IN ARREST SETTING
none
Contraindications
NON-ARREST
- myasthenia gravis 2. closed-angle glaucoma 3. atrial fibrillation and flutter 4. known hypersensitivity 5. thyrotoxicosis 6. urinary tract obstruction
Precautions
- Atropine may actually worsen 2nd degree Type II & 3rd degree AV blocks. Many experts go as far as to indicate atropine is relatively contraindicated in this setting & transcutaneous pacing is preferred.
- Cardiovascular disease including: CAD & CHF
- COPD
- HTN
- Renal/hepatic disease
- Geriatrics
- Pregnancy I
- Minimum Doses <0.5 mg in adults<0.1 mg in children Smaller doses can cause a paradoxical bradycardia.
Dosage
ADULTS
- Symptomatic Bradycardia: IV: 0.5 mg to 1 mg every 3-5
minutes.Max dose: 0.04 mg/kg (full vagal
blockade). - Poisonings : IV/IM/ETT/IO: 1-2 mg as needed to
decrease cholinergic symptoms.
AUTOINJECTOR (MARK 1 KIT): 2 mg
Dosage
PEDI
Symptomatic Bradycardias: IV/IO: 0.02 mg/kg repeated
every 3-5 minutes as needed. Child: Minimum—0.1
mgMaximum—0.5 mgAdolescent:Minimum—0.1
mgMaximum—1 mgETT: 2-3 times the IV dose diluted in
3-5 ml NS
•Poisonings: IV/IM: 0.05 mg/kg IV every 3-5 minutes as
needed to decrease cholinergic symptoms.
•Pediatric Pre-Intubation: IV/IO: 0.02 mg/kg
Onset
Rapid
Duration
2-6 hrs
Side Effects
•Anticholinergic Effects: Remember the mneumonic:DRY
AS A BONE—Dry mucous membranes, urinary retention,
constipationMAD AS A HATTER—Restlessness,
tachycardia, palpitations, HA, dizzinessRED AS A BEET—
Flushed, hot, & dry skin BLIND AS A BAT—Pupillary dilation
(mydriasis), blurred vision (cycloplegia), photophobia •Tachydysrhythmias, Ventricular Tachycardia/Fibrillation
•Of course…N/V
Interactions
- Anticholinergics increase vagal blockade.
- Potential adverse effects when administered with
digitalis, cholinergics, neostigmine. - Enhanced effects are possible with antihistamines,
procainamide, quinidine, antipsychotics,
antidepressants, benzodiazepines, phenothiazines. - When administered too soon after NaHCO3 (i.e. Without
allowing sufficient fluid to flush the line), a precipitate will
form.
Special Notes
- To recognize cholinergic poisonings remember the
SLUDGE, DUMBELS, and Days of the week mnemonics. 2. Pushing a less than the minimum dose or pushing
atropine too slowly may elicit a paradoxical
bradycardia. - Remember most bradycardias in pediatrics are a result of
hypoxia/hypoxemia rather than a primary cardiac
problem. Ventilation is always preferred over
pharmacological intervention. - Avoid being splashed in the eyes with atropine.•Be
prepared, on physician order, to deliver massive
amounts (10-40mg) in the setting of cholinergic
poisoning.
SLUDGE
Salivation Lacrimation Urination Defecation GI distress Emesis
DUMBELS
muscarinic
Diarrhea Urination Miosis Bradycardia/bronchospasm/bronchorrhea Emesis Lacrimation Salivation/secretion/sweating
BAM
Breathing difficulty (wheezing) Arrhythmias (bradycardia, ventr. arrhythmias, AV blocks) Miosis (pinpoint pupils)
Three C’s of CNS effects
Confusion
Convulsions
Coma
Days of the Week (Nicotenic)
Mydriasis Tachycardia Weakness Hypertension, Hyperglycemia Fasciculations
