WHO Model Prescribing Information: Drugs Used in Anaesthesia
(1989; 60 pages) [French] View the PDF document
Table of Contents
View the documentPreface
View the documentIntroduction
Close this folderPremedication
View the documentAtropine
View the documentChloral hydrate
View the documentDiazepam
View the documentPromethazine
Open this folder and view contentsGeneral anaesthetics and oxygen
Open this folder and view contentsLocal anaesthetics
Open this folder and view contentsNon-opioid analgesics
Open this folder and view contentsOpioid analgesics and antagonists
Open this folder and view contentsMuscle relaxants and cholinesterase inhibitors
Open this folder and view contentsBlood substitutes
Open this folder and view contentsSolutions for correcting water and electrolyte imbalance
Open this folder and view contentsAntacid for use in obstetric practice
View the documentAnaesthesia at the District Hospital
View the documentSelected WHO publications of related interest
View the documentBack cover
 

Atropine

Group: anticholinergic agent
Tablet: 1 mg (sulfate)
Injection: 1 mg (sulfate) in 1-ml ampoule

General information

Atropine is an alkaloid of Atropa belladonna that competitively antagonizes the muscarinic action of acetylcholine and other cholinergic drugs.

Atropine is readily absorbed from the gastrointestinal tract. Its half-life in plasma ranges from 2 to 3 hours. It is largely metabolized in the liver and excreted in the urine.

Clinical information

Uses

In general surgery:

• to inhibit salivary and bronchial secretions particularly during ether or ketamine anaesthesia (preoperative medication)

• to inhibit cardiac dysrhythmias, bradycardia and hypotension resulting from excessive vagal stimulation

• to block the parasympathomimetic effects of anticholinesterase agents used to restore muscular activity on completion of surgery.

Dosage and administration

Pre-anaesthetic medication

Adults: 20 micrograms/kg i.m. 30-60 minutes before induction, or up to a maximum of 500 micrograms i.v. immediately before induction.

Children: 20 micrograms/kg i.m. 30-60 minutes before induction, or the same dose orally 2 hours before induction.

Inhibition of cardiac dysrhythmias

Adults: 400-1000 micrograms i.v.
Children: 10-30 micrograms/kg i.v.

Restoration of muscular activity

Adults: 600-1200 micrograms i.v. 2-3 minutes before administration of the anticholinesterase agent.
Children: 20 micrograms/kg administered as above.

Precautions

Atropine should be used at reduced dosage in the elderly and in patients with cardiovascular insufficiency, hyperthyroidism, hypertension or hepatic or renal insufficiency.

Use in pregnancy

Atropine should be used during pregnancy only when the need outweighs any possible risk to the fetus.

Adverse effects

Signs of parasympathetic blockade commonly occur within the therapeutic dosage range. These include dry mouth, blurred vision, raised ocular tension, flushing and dryness of skin, skin rashes and difficulty in micturition, which occasionally results in urinary retention.

Less common are atrial dysrhythmias, ventricular tachycardia or fibrillation and confusional states.

Heat prostration and convulsions can occur, especially in febrile children. This risk is intensified in a hot, humid environment.

Overdosage

Serious overdosage is characterized by signs of parasympathetic blockade, central excitation, skin rash and hyperpyrexia. Hallucinations, mania and delirium may be followed by convulsions. Circulatory and respiratory collapse are terminal events.

Treatment consists of symptomatic and supportive therapy. Activated charcoal should be administered followed by gastric aspiration. Neostigmine (250 micro-grams subcutaneously) will reverse the peripheral but not the central effects of atropine. Small doses of diazepam may help delay excitation. Fever may be reduced by sponging with tepid water. Mechanically assisted respiration may be required.

Storage

Atropine injection and tablets should be stored in hermetically closed containers protected from light, and should not be allowed to freeze.

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