Atropine eyedrops
ISOPTO ATROPINE
Pronunciation: A-troe-peen
“AT-AT dropping”
Anticholinergics dilate pupils
“Mad as a hatter” → BBB-crossing antimuscarinic
What it isTopical antimuscarinic for mydriasis, cycloplegia, and amblyopia penalization. Used off-label sublingually for clozapine-induced hypersalivation.
Why this oneIts prolonged cycloplegia enables patch-free amblyopia penalization, pediatric refraction, and relief of ciliary spasm.
What limits itOcular dosing yields ~64% systemic bioavailability (plasma t1/2 ~2.5 h); the label restricts use under 3 months and flags Down syndrome susceptibility.
FDA-approved for
- mydriasis / cycloplegia (1960)
- amblyopia (penalization of the healthy eye) (1960)
Classes and tags
Clinical profile
Legacy pregnancy categoryC
Defining liabilityGenerally tolerated at therapeutic doses; clinically important risks are agent-specific and increase with interactions or organ impairment.
FDA label
Read the full label on DailyMed ↗
NO BOXED WARNINGS
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Mydriasis; cycloplegia; penalization of healthy eye in amblyopia | ≥3 months | 1 drop to conjunctival cul-de-sac, 40 min before intended maximal dilation time | Same | See age limits |
| Same indications — repeat dosing | ≥3 years | May repeat up to BID PRN | — | BID |
| Same indications — age cap | <3 years | ≤1 drop per eye QD | — | 1 drop/eye/day; <3 months not recommended |
Renal Undefined
Hepatic Undefined
Not recommended <3 months of age; <3 years limit to ≤1 drop per eye per day
Instructions
- Instill topically into the cul-de-sac of the conjunctiva
- Administer 40 min before intended maximal dilation time
Available strengths
- drops 1 %
- sol 8 mg/20 mL
- ointment 10 mg/g
- inj 0.25, 0.5, 1 mg
Cautions
- Photophobia and blurred vision (pupil unresponsiveness/cycloplegia) may last up to 2 weeks
- Blood pressure elevation from systemic absorption reported at recommended doses
- Down syndrome, spastic paralysis, or brain damage: increased susceptibility to CNS, cardiopulmonary, and GI toxicity from systemic absorption
Adverse reactions
- Ocular: eye pain/stinging on instillation, blurred vision, photophobia, superficial keratitis, decreased lacrimation; less common allergic (papillary conjunctivitis, contact dermatitis, eyelid edema)
- Systemic (antimuscarinic): dry skin/mouth/throat, drowsiness, restlessness/irritability/delirium, tachycardia, increased BP, flushed face/neck
Pregnancy No adequate human studies; systemically bioavailable after ocular dosing — use only if potential benefit justifies fetal risk
Lactation Unknown presence in milk/effects on infant or production; weigh benefits vs maternal need
Cost
| Strength | #/mo | generic $/unit | CostPlus | |
|---|---|---|---|---|
| 1 % | drops | per unit | not offered |
Other forms: Atropine (ATROPEN)
Available combined with: Difenoxin (in MOTOFEN) · Diphenoxylate (in LOMOTIL) · diphenoxylate / atropine
Open Atropine eyedrops in the interactive console ↗
Memory aids: interaction avatars
Open Atropine eyedrops in the interactive console ↗
Self-check
- What off-label sublingual use is stated for ophthalmic atropine?
Clozapine-induced hypersalivation. - Below what age does the ocular label restrict atropine use?
Under 3 months.