Atropine

TRADE NAME: Atropine, Atropa

CLASS: Anticholingeric
Description: Anticholingeric, antimuscarinic, parasympatholytic
ACTIONS: Decreases vagal tone resulting in positive chronotropic effect & increases AV conduction. Competitive antagonist for acetylcholine at muscarinic receptors. Atropine bronchodilates via parasympatholytic mechanism.
INDICATIONS: Hemodynamically significant bradycardia and asystole. Cholinergic poisoning by certain mushrooms (Amanita spp.), insecticides (carbamates, acetycholinesterase inhibitors), and nerve gas.
PHARMACOKINETICS:
Onset: < 2 minutes
Peak Effect: 2 – 4 min. IV (20 – 60 min. IM)
Duration: 4 hours
Half Life: 2 – 3 hours
CONTRAINDICATIONS: No significant contraindications, however, may worsen bradycardia associated with Mobitz-Type 2 and complete heart block. Use transcutaneous pacing if available. Use with extra caution in patients with symptoms of myocardial ischemia.
SIDE EFFECTS:

  • CNS: Pupillary dilation, confusion, restlessness, drowsiness, seizure
  • CV: Tachycardia, paradoxical bradycardia
  • Resp: Can cause mucus plugs due to drying of secretions
  • GI/GU: Dry Mouth

INTERACTIONS: Additive anticholinergic effects with antihistamines, phenothiazines, antipsychotics, tricyclic antidepressants, procainamide, other anticholinergics drugs. Caution with SSRIs.
DOSAGE:
ADULT:

  • Symptomatic Bradycardias: 0.5 – 1.0mg IV push; may be repeated q 3-5 minutes to a maximum of 0.04mg/kg; (2.5 – 3mg adults) results in full vagal blockage. Doses of less than 0.5mg may cause further slowing of the heart rate.
  • Asystole & PEA: 1.0mg IV; may be repeated q 3-5 minutes for total of 3mg. ETT-2.0mg
  • Organophosphate Poisoning: 1mg rapid IV, 2nd 1mg slow IV; larger doses may be required. Dosage exceeding 4mg by physician order only.

PEDIATRIC: 0.05mg/kg IV, IM, IO every 10-15 min.
ROUTE: IV, IO, ET (May be administered via *ABT in some cases of bronchospasm. Smaller doses of atropine are indicated for the elderly.)
NOTES: Monitor vital signs carefully.