Phenylephrin Inj
General Drug Information and Indications
Alpha-1 adrenergic agonist (phenylephrine) for treatment of hypotension; ophthalmic mydriasis; reversal of equine penile prolapse; nasal decongestion.
Selective alpha-1 adrenergic agonist (phenylephrine HCl). Mechanism: stimulates alpha-1 receptors → peripheral vasoconstriction (IV use for hypotension); ophthalmic: iris dilator muscle stimulation → mydriasis. Used to reverse penile prolapse in horses (IV bolus for vasoconstriction of corpus cavernosum).
Key information
Alpha-1 adrenergic agonist. Ophthalmic: mydriasis and vasoconstriction. Injectable: vasopressor — monitor blood pressure closely. IV: titrate to effect. Do not administer in IV bag with alkaline solutions.
How to Give this Medication
Ophthalmic: Instill into the conjunctival sac; avoid touching dropper tip to eye or periocular tissue. 1 drop per eye. IV (horses): dilute and administer slowly with BP monitoring. Store at room temperature; protect from light.
If a dose is missed
This medication is administered by a veterinarian or veterinary staff in a clinical setting. Missed doses are managed by your veterinary team — contact your veterinarian to reschedule.
Side Effects
Ophthalmic: transient stinging, burning. Cardiovascular (systemic absorption): hypertension, reflex bradycardia, arrhythmias. Topical nasal: rhinitis medicamentosa with prolonged use. IV: severe hypertension if overdosed; arrhythmias.
Precautions
For animals
Ophthalmic: mydriasis only — no cycloplegia (use tropicamide for cycloplegia). Systemic use: monitor blood pressure and heart rate closely. Avoid in patients with hyperthyroidism or cardiovascular disease.
For people handling this medication
Wash hands thoroughly with soap and water after handling. Avoid contact with eyes; if contact occurs, flush with water for 15 minutes and seek medical attention. Keep out of reach of children. If accidental ingestion occurs, contact Poison Control (1-800-222-1222). Alpha-1 agonist — avoid ingestion (causes hypertension). Wash hands thoroughly with soap and water after handling. Ophthalmic: avoid human eye contact. Keep out of reach of children.
Overdose
Contact your veterinarian. Phenylephrine overdose causes severe hypertension. Medical emergency.
Phenylephrin Inj dosage forms
| Product | Strength | Form | Size | Type |
|---|---|---|---|---|
| PHENYLEPHRINE 10MG/ML 1ML VIAL | 10 MG/ML | Injectable | 1 | Commercial |
| PHENYLEPHRIN SOL 2.5% OP | — | — | — | Commercial |
Sources
This information is provided for educational purposes and is not a substitute for advice from your veterinarian. Source: Merck Veterinary Manual (merckvetmanual.com); Plumb's Veterinary Drug Handbook (Plumb, D.C., app.plumbs.com)