Atropine
Atropine 0.5%, 1%, 2% · ophthalmic solution
Mydriatics/Cycloplegics
Approved uses
Cycloplegia and mydriasis
1 drop to the conjunctival cul-de-sac 40 minutes before intended maximal dilation, from 3 months of age; may be repeated up to twice daily from 3 years of age.
Dilation begins within 40 minutes, peaks at about 2 hours, and can persist up to 2 weeks.
Penalization of the healthy eye in amblyopia
1 drop to the sound eye once daily; weekend-only dosing (2 days per week) was equally effective at 4 months. The label sets no amblyopia-specific frequency and caps repeat dosing at twice daily from 3 years of age.
Acuity gain equals patching, and weekend-only dosing works as well as daily dosing.
OFF-LABELNot in the FDA label for this product
Myopia progression control in children
1 drop nightly OU of 0.01%, 0.025%, or 0.05% (LAMP) or of 0.01%, 0.1%, or 0.5% (ATOM2); these are prepared low concentrations, not this 1% product.
RCTs · n=438 · US trial null
LAMP randomized 438 children aged 4 to 12 to nightly 0.05%, 0.025%, 0.01%, or placebo, with 1-year spherical equivalent change of -0.27, -0.46, -0.59, and -0.81 D (P < 0.001) and 0.05% still the optimal concentration at 3 years in that Chinese cohort. ATOM2 randomized 400 children aged 6 to 12 to nightly 0.5%, 0.1%, or 0.01% for 2 years (progression -0.30, -0.38, and -0.49 D, differences the authors judged clinically insignificant), and the 0.01% arm had the smallest rebound in the washout year. A US randomized placebo-controlled trial of 0.01% in 187 children found no effect at 24 months (adjusted difference -0.02 D, 95% CI -0.19 to +0.15 D), so benefit at the lowest concentration is not established in every population.
Contraindications
Hypersensitivity or previous allergic reaction to any ingredient in the formulation.
Available Forms1% solution (10 mg/mL atropine sulfate, 8.3 mg/mL base), 2 mL, 5 mL, 15 mL dropper bottles
Mechanism of ActionReversible, relatively nonselective muscarinic antagonist; potency at nicotinic receptors is much lower and other receptor actions are not clinically detectable. Blocking muscarinic activation of the pupillary constrictor leaves sympathetic dilator tone unopposed, giving mydriasis, and weakening ciliary muscle contraction gives cycloplegia with loss of accommodation for near.
Warnings & Precautions
- Photophobia and blurred vision: Pupil unresponsiveness and cycloplegia may last up to 2 weeks.
- Blood pressure elevation: Reported after conjunctival instillation of recommended doses of the 1% solution.
- MAO inhibitor interaction: Concurrent use is generally not recommended, given the potential to precipitate hypertensive crisis.
- Pediatric overdose: 10 mg or less may be fatal in a child; physostigmine reverses delirium and coma but is short lived and may need repeating.
Common Side Effects
- Ocular, most common: Eye pain and stinging on instillation, blurred vision, photophobia, decreased lacrimation, superficial keratitis.
- Ocular, allergic: Papillary conjunctivitis, contact dermatitis, lid edema; less common.
- Systemic: Increased heart rate and blood pressure, dryness of skin, mouth, and throat, flushed skin of face and neck, restlessness, irritability, delirium.
Pregnancy & LactationPregnancy: No adequate and well-controlled studies in pregnant women and no animal development or reproduction studies; use only if the potential benefit justifies the potential fetal risk.
Lactation: Traces have been found in human milk after administration of the injectable solution, and topical dosing produces some systemic absorption.
Pediatric UseNot recommended under 3 months; under 3 years limit to one drop per eye per day.