Atropine (1% w/v) is a sterile ophthalmic solution containing the antimuscarinic alkaloid atropine sulfate, equivalent to 1% w/v atropine. It is a non-selective, competitive antagonist of acetylcholine at muscarinic receptors (M1-M5). In ophthalmology, it acts as a potent cycloplegic (paralyzing the ciliary muscle) and mydriatic (dilating the pupil), with a very long duration of action. Its primary clinical use in India is for cycloplegic refraction in children, treatment of uveitis, and as a penalization therapy in amblyopia management. It is also used pre-operatively in ophthalmic surgery and in the management of acute iridocyclitis.
Adult: For uveitis: Instill 1-2 drops into the affected eye(s) up to 3-4 times daily. For pre-operative mydriasis: 1-2 drops, 1 hour before surgery. Frequency and duration are highly indication-specific and must be individualized.
Note: 1. Wash hands. 2. Tilt head back. 3. Gently pull lower eyelid to form a pouch. 4. Instill prescribed number of drops. 5. Close eyes gently and apply pressure to the lacrimal sac (inner corner of eye) for 1-2 minutes to minimize systemic absorption. 6. Do not blink excessively. 7. Do not touch dropper tip to any surface. 8. Wait at least 5-10 minutes before instilling any other eye drop.
Atropine competitively blocks the action of acetylcholine at postganglionic muscarinic receptors in the sphincter pupillae and ciliary muscles of the eye. Blockade of the parasympathetic tone allows unopposed sympathetic action, leading to relaxation of the sphincter pupillae (causing mydriasis) and relaxation of the ciliary muscle (causing cycloplegia or paralysis of accommodation).
Pregnancy: FDA Pregnancy Category C. Animal studies show adverse effects. No adequate, well-controlled studies in pregnant women. Use only if the potential benefit justifies the potential risk to the fetus. Can cross the placenta and may cause fetal tachycardia.
Driving: STRICTLY NOT ADVISED during treatment due to significant blurring of vision (loss of accommodation) and photophobia. Effects can last for days to weeks after discontinuation.
| Other anticholinergic drugs (e.g., Ipratropium, Oxybutynin, Tricyclic Antidepressants, Phenothiazines) | Additive systemic anticholinergic side effects (dry mouth, constipation, urinary retention, tachycardia, confusion). | Major |
| Potassium Chloride (wax-matrix tablets) | Increased risk of GI lesions due to reduced GI motility. | Moderate |
| Digoxin | Increased serum digoxin levels due to reduced GI motility, potentially leading to toxicity. | Moderate |
| Ketoconazole, Macrolide antibiotics | Potential to inhibit atropine metabolism, increasing systemic levels. | Moderate |
| Pilocarpine, Carbachol (miotics) | Pharmacological antagonism; atropine will counteract the effects of these drugs. | Major |
Same composition (Atropine (1% w/v)), different brands: