Sanmyd-P Mechanism of Action

Pharmacology: Tropicamide + Phenylephrine Hydrochloride (Sanmyd-P) rapidly causes mydriasis required for funduscopy and cycloplegia for refractometry. These symptoms disappear in a comparatively short time after the completion of these examinations.
Tropicamide + Phenylephrine Hydrochloride (Sanmyd-P) is a mydriatic for diagnostic purposes, which contains tropicamide (a parasympatholytic agent) and phenylephrine hydrochloride (a sympathomimetic agent) and with the synergism between these two ingredients, it can be used to achieve mydriasis and cycloplegia, irrespective of the patient's age.
Pharmacodynamics: Mydriatic Effect: When ophthalmic solutions containing tropicamide and phenylephrine hydrochloride at various concentrations were instilled into the eyes of albino rabbits, mydriasis was produced by tropicamide-induced relaxation of the iris sphincter muscle and phenylephrine hydrochloride-induced contraction of the iris dilator muscle. The mydriatic effect was enhanced at the tropicamide-to-phenylephrine ratio of 1:1 by the synergistic effect of both ingredients.
Cycloplegic Effect: This product was instilled into the eye once or twice for refractometry in children with impaired visual acuity or convergent squint, and the cycloplegic effect of this product was compared with that of 0.5% or 1% atropine after instillation 3 times daily for 3 days. This product was weaker in cycloplegic effect than atropine.
Pharmacokinetics: No data.