Section 19 · Monograph
Atropine 1% (sublingual drops)
Reviewed Nov 2026FDA label
Isopto Atropine (ophthalmic, used SL)Anticholinergic
- Forms
- Ophthalmic solution: 1% (10mg/mL)
- Dose
- Sialorrhea or terminal secretions (off-label): 1-2 drops sublingually every 4h as needed
- MOA
- Muscarinic receptor antagonism
Indications
- Ophthalmic use: cycloplegia, mydriasis and amblyopia treatment (labeled indications of atropine 1% ophthalmic solution)FDA-labeled
Off-Label Uses
- Sublingual use for sialorrhea and terminal respiratory secretionsOff-label
Mechanism of Action
- Competitive muscarinic receptor antagonist reducing salivary and bronchial secretions; crosses the blood-brain barrier and can cause delirium
Full Dosing
Adult / usual
- Sialorrhea or terminal secretions (off-label): 1-2 drops of 1% solution placed under the tongue every 4 hours as needed
- Use the lowest effective dose; stop if delirium, urinary retention or marked tachycardia develop
- Does not remove existing secretions; most effective when started early
Contraindications
- Angle-closure glaucoma
- Hypersensitivity to atropine
- Relative: urinary retention, obstructive GI disease, tachyarrhythmia
Drug Interactions
- Other anticholinergics (hyoscyamine, scopolamine, TCAs, antihistamines): additive effects
- Cholinesterase inhibitors (donepezil, rivastigmine, pyridostigmine) oppose effects
Adverse Effects
- Dry mouth, tachycardia
- Urinary retention, constipation
- Delirium and agitation, especially in older adults
- Flushing and blurred vision
Monitoring Parameters
- Secretion burden and comfort
- Mental status
- Heart rate and urinary output
Pregnancy & Lactation
- Limited data; crosses the placenta
- Present in milk in small amounts; may reduce supply