|Reviewed by Dr
Carl Kuschel, Dorothy Cooper
Dose and Administration
- 10-30 micrograms/kg/dose IV over 1 minute, IM
or ETT (ETT route to be used only if IV route not possible).
- Dose may be repeated every 10-15 minutes to
achieve desired effect, with a maximum total dose of 40 micrograms/kg.
- Severe sinus bradycardia, particularly when
parasympathetic influences on the heart (digoxin, beta blocker drugs,
hyperactive carotid sinus reflex) predominate.
- To reduce the muscarinic effects of neostigmine
when reversing neuromuscular blockade.
- Prevention of reflex bradycardia during
Contraindications and Precautions
- Known hypersensitivity to atropine.
- Abdominal distension with decreased peristalsis
and/or intestinal obstruction.
- Gastroesophageal reflux.
- Obstructive uropathy.
- Congenital glaucoma.
- Caution in patients with Down Syndrome.
Atropine, a naturally occurring alkaloid, is an
anticholinergic agent. Acts by competitive inhibition of the actions of
acetylcholine on muscarinic receptors. Increases heart rate by decreasing the
effects of the parasympathetic system while increasing the effects of the
sympathetic system. Vagal influences on the gastrointestinal tract are partially
inhibited by atropine. Motor activity in the stomach and small and large
intestines is reduced. Oesophageal sphincter tone is reduced. Salivary secretion
is inhibited. Atropine relaxes bronchial and bronchiolar smooth muscle, thereby
reducing airway resistance and increasing dead space by 30%.
Rapid absorption from intestinal tract but not
the stomach. Pharmacological activity of parenteral administration is 2-3 times
greater than enteral administration. Low binding (20%) to human plasma protein.
Excreted mainly unchanged via the urine.
Rapid onset of action. Peak effects:
cardiovascular (12-16 minutes), gastrointestinal tract (1-2 hours). Duration
of action 4-6 hours.
Possible Adverse Effects
- Urinary retention
- Impaired gastrointestinal motility
- Hot, dry scarlet flushed skin
- Cardiac arrhythmias
- Dry mucous membranes, dry mouth
- Limited use in newborn infants. Should not be
used in neonatal resuscitation.
- Management of atropine toxicity: stop atropine,
treat anticholinergic symptoms with physostigmine 0.5 mg by slow IV infusion.
- Sodium chloride content 9mg.