Tropicamide
Mydriatics and cycloplegics
Mydriatics and cycloplegics
A short-acting antimuscarinic eye drop that widens the pupil for eye examinations. The effect wears off within the day.
Quick facts
- Group
- Mydriatics and cycloplegics
- Target
- Muscarinic acetylcholine receptors of the iris sphincter and ciliary muscle
- Used for
- Pupil dilation for examination
- Key effects
- Brief stinging · Blurred vision and light sensitivity
- Monitor
- Behaviour · Eye pain
- ATC
- S01FA06
No doses: the clinician sets them by the current guideline.
Mechanism of action
Tropicamide blocks muscarinic receptors, so acetylcholine can no longer contract the iris sphincter (the pupil widens: mydriasis) or the ciliary muscle (focusing is paralysed: cycloplegia). Its cycloplegia is weaker and shorter than that of cyclopentolate or atropine, which makes it the usual drop for a dilated fundus examination.
- Tropicamide blocks muscarinic receptors in the eye
- The iris sphincter relaxes: the pupil widens
- The ciliary muscle relaxes: near focus is lost for a while
Indications
- Pupil dilation for examination of the retina, for example diabetic retinopathy screening Diabetic retinopathy →
- Cycloplegia for diagnostic procedures
Adverse effects
Common
- Brief stinging
- Blurred vision and light sensitivity
- Superficial punctate keratitis
- Dry mouth, fast heart rate, headache
Contraindications
- Hypersensitivity to any component
- Not for injection
Key interactions
- Carbachol, pilocarpine or ophthalmic cholinesterase inhibitors
- Tropicamide can counteract their pressure-lowering effect
What is monitored
- Behaviour, heart rate and breathing in children after the drops
- Eye pain, halos or a red eye after dilation (raised pressure)
Administration and safety
- Pressure on the lacrimal sac after the drop reduces systemic absorption.
- Contact lenses come out before the drops.
- The dropper tip must not touch any surface.
Pregnancy and breastfeeding
No animal reproduction studies exist; it is used in pregnancy only if clearly needed.
Nursing care
- Warn that vision will be blurred and light will be uncomfortable for several hours; the patient should not drive while dilated.
- Suggest sunglasses to protect the eyes from bright light.
- Watch children for agitation, confusion, flushing or a fast pulse.
- Ask the patient to report eye pain or halos after the exam.
Pharmacokinetics
- Onset and duration
- Acts in about 15–30 minutes and lasts about 3–8 hours; full recovery can take up to 24 hours; dark irides may need more drops
Test yourself
Think of the answer, then tap the question to see it.
Why does tropicamide dilate the pupil?
It blocks muscarinic receptors, so the iris sphincter relaxes.
Why is tropicamide preferred over atropine for a routine fundus examination?
Its effect is short (hours, not days) and its cycloplegia is weaker.
Which patients are most at risk of central nervous system effects from mydriatic drops?
Children.
Connections
← Back to the class: Mydriatics and cycloplegics
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: DailyMed - TROPICAMIDE solution/ drops (DailyMed (U.S. National Library of Medicine), 2026); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).
Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake
Representative model, for educational purposes only.