Which of these drugs is classified as a miotic?

Which of these drugs is classified as a miotic?

• A. Tropicamide
• B. Atropine
• C. Pilocarpine
• D. Phenylephrine

Answer: (C)

Pilocarpine is classified as a miotic because it stimulates the sphincter muscle of the iris, leading to constriction of the pupil. Miotics are drugs that cause the pupil to constrict, and pilocarpine is particularly used in the treatment of glaucoma to reduce intraocular pressure by facilitating drainage of aqueous humor through the trabecular meshwork. This action helps in managing increased intraocular pressure, which is a key factor in glaucoma. Other options, such as tropicamide and atropine, are classified as mydriatics since they cause dilation (enlargement) of the pupil by blocking the action of acetylcholine on the iris sphincter. Phenylephrine also serves as a mydriatic, as it is an alpha-adrenergic agonist that dilates the pupil by stimulating the radial muscles of the iris. Thus, while other options affect pupil size differently, pilocarpine distinctly promotes constriction, making it the correct answer in this context.

Pilocarpine is classified as a miotic because it stimulates the sphincter muscle of the iris, leading to constriction of the pupil. Miotics are drugs that cause the pupil to constrict, and pilocarpine is particularly used in the treatment of glaucoma to reduce intraocular pressure by facilitating drainage of aqueous humor through the trabecular meshwork. This action helps in managing increased intraocular pressure, which is a key factor in glaucoma.

Other options, such as tropicamide and atropine, are classified as mydriatics since they cause dilation (enlargement) of the pupil by blocking the action of acetylcholine on the iris sphincter. Phenylephrine also serves as a mydriatic, as it is an alpha-adrenergic agonist that dilates the pupil by stimulating the radial muscles of the iris. Thus, while other options affect pupil size differently, pilocarpine distinctly promotes constriction, making it the correct answer in this context.