atropine sulfate: clinical use

Prescribing considerations

• Confirm the indication and product because ophthalmic and injectable presentations have different licensed roles.
• Myopia treatment should be initiated and reviewed by an appropriately skilled eye-care professional; exclude syndromic or secondary causes.
• Systemic exposure may be reduced by punctal occlusion after eye-drop administration.
• Use additional caution in older people, children and people with relevant cardiac, renal, hepatic, gastrointestinal, urinary or respiratory risks.
• In heart-transplant recipients, paradoxical atrioventricular block or sinus arrest has been reported; ECG monitoring and immediate pacing capability are advised.

Contraindications and cautions

• Hypersensitivity to atropine or product excipients.
• The selected myopia eye drops are contraindicated in primary or angle-closure glaucoma and hypersensitivity to related anticholinergics.
• Selected injections list angle-closure or narrow-angle glaucoma, significant urinary outflow obstruction, paralytic ileus and other serious obstructive gastrointestinal disorders as contraindications.
• Myasthenia gravis is contraindicated for selected injections unless atropine is used with an anticholinesterase. Check product-specific contraindications.

Monitoring

• For myopia: refractive progression, visual function, photophobia, accommodation effects, ocular irritation and corneal-surface problems.
• For systemic use: heart rate and rhythm, haemodynamic response, temperature, mental state, urinary retention and respiratory secretion retention.
• After suspected toxicity: airway, breathing, circulation, temperature, neurological state and cardiac rhythm.

Clinical pharmacology

A competitive, reversible antagonist at muscarinic acetylcholine receptors. Systemic administration increases sinoatrial activity and atrioventricular conduction, while ocular administration causes mydriasis and cycloplegia.

Formulation and product differences

• The selected ophthalmic product is a preserved solution containing benzalkonium chloride and is licensed for progressing childhood myopia.
• Selected injection products are clear sterile ampoule solutions for intravenous, intramuscular or subcutaneous administration.
• Injectable presentations differ in concentration and compatibility details; verify the exact product before preparation or administration.
• Selected injection products are physically incompatible with several substances, including alkalis, sodium bicarbonate and noradrenaline bitartrate.

Eye drops

Route: Ophthalmic

Strengths: 0.1 mg/mL, 1.0% w/v, 1%, 1% w/v

Injection

Route: Parenteral

Strengths: 600 micrograms/1 mL, 600 micrograms/mL, 1 mg/1 mL