Mydfrin

Phenylephrine Hydrochloride Ophthalmic Solution 2.5%: Diagnostic Mydriatic Agent

Phenylephrine Hydrochloride Ophthalmic Solution is a topical sympathomimetic medication used primarily as a Mydriatic (pupil dilator). While originally approved for human use, it is frequently utilized by veterinarians on an extra-label basis for dogs, cats, and horses. Phenylephrine works by stimulating the alpha-adrenergic receptors of the iris dilator muscle, causing the pupil to widen without significantly affecting the pet's ability to focus (unlike Atropine). It is also used to temporarily reduce redness by constricting surface blood vessels and as a diagnostic tool for certain neurological conditions, such as Horner’s Syndrome.

Key Information

• Active Ingredient: Phenylephrine Hydrochloride (2.5%).

• Approved Species (Original Licensing): Human.

• Common Veterinary Species: Dog, Cat, and Horse (used extra-label).

• Uses: Pupil dilation for eye exams, diagnostic testing for Horner’s Syndrome, and reducing conjunctival congestion (redness).

• Form: Ophthalmic Solution.

• Route of Administration: Ophthalmic (Eye Drops).

Prescription Required

Phenylephrine Hydrochloride Ophthalmic Solution is a prescription-only medication. A valid prescription from a licensed veterinarian is required for purchase. Professional oversight is necessary because this medication can cause a transient increase in blood pressure or heart rate in some patients. It should be used with caution in pets with pre-existing heart disease, hypertension, or glaucoma. Your veterinarian will determine if this medication is appropriate based on your pet's cardiovascular health and the specific ocular condition being treated.