CYCLOPENTOLATE HYDROCHLORIDE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for CYCLOPENTOLATE HYDROCHLORIDE (CYCLOPENTOLATE HYDROCHLORIDE).
Antimuscarinic agent; blocks acetylcholine at muscarinic receptors in the sphincter and ciliary muscles of the iris, producing mydriasis and cycloplegia.
| Metabolism | Primarily hepatic metabolism via ester hydrolysis in plasma and liver; limited data on specific CYP enzymes. |
| Excretion | Renal excretion of unchanged drug and metabolites accounts for approximately 60-70% of elimination; the remainder is biliary/fecal. |
| Half-life | Terminal elimination half-life is approximately 2.5 hours in adults; shorter in children (~1-2 hours) and prolonged in elderly or hepatic impairment. |
| Protein binding | Approximately 60-70% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | Approximately 1.5-2.5 L/kg, indicating extensive tissue distribution. |
| Bioavailability | Ophthalmic: systemic bioavailability is low (approx. 1-5%) due to limited corneal absorption and nasolacrimal drainage; oral bioavailability is not clinically relevant. |
| Onset of Action | Ophthalmic: mydriasis within 5-15 minutes; cycloplegia within 15-30 minutes. |
| Duration of Action | Mydriasis lasts up to 24 hours; cycloplegia may persist for 6-24 hours depending on dose and individual response. |
1-2 drops of 0.5-1% solution, repeat in 5-10 minutes if necessary; or 0.1-0.5 mL of 1% solution subconjunctivally.
| Dosage form | SOLUTION/DROPS |
| Renal impairment | No dose adjustment required; drug is primarily metabolized locally and systemically with minimal renal excretion. |
| Liver impairment | No dose adjustment required; drug is metabolized locally and systemically, but hepatic impairment unlikely to affect ocular efficacy. |
| Pediatric use | Infants and children: 1 drop of 0.5-1% solution, may repeat once after 5 minutes; maximum 2 drops per eye. |
| Geriatric use | Use lower concentration (0.5%) due to increased risk of systemic side effects and prolonged cycloplegia; monitor for acute angle-closure glaucoma. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for CYCLOPENTOLATE HYDROCHLORIDE (CYCLOPENTOLATE HYDROCHLORIDE).
| Breastfeeding | Limited data; M/P ratio unknown; systemic absorption after ophthalmic use is minimal; unlikely to cause adverse effects in breastfed infant; use caution. |
| Teratogenic Risk | First trimester: No human data; animal studies not conducted; theoretical risk of systemic anticholinergic effects at high doses. Second/third trimester: Limited reports; no evidence of teratogenicity with ophthalmic use; potential for fetal tachycardia if systemic absorption occurs. |
| Fetal Monitoring |
■ FDA Black Box Warning
No FDA boxed warning exists.
| Serious Effects |
["Hypersensitivity to cyclopentolate or any component","Narrow-angle glaucoma","Untreated primary open-angle glaucoma (relative contraindication)"]
| Precautions | ["May increase intraocular pressure; use with caution in glaucoma or narrow iridocorneal angle","Central nervous system effects (e.g., hallucinations, confusion, behavioral disturbances) especially in children","Photophobia and blurred vision due to mydriasis","Tachycardia and hypertension with systemic absorption"] |
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| Monitor maternal heart rate and blood pressure for systemic anticholinergic effects; fetal heart rate monitoring if maternal tachycardia occurs. |
| Fertility Effects | No known effects on fertility; no human or animal data available. |