How Do Ophthalmic Alpha Agonists Work?

Reviewed on 4/22/2021

How Do Ophthalmic Alpha Agonists Work?

Ophthalmic alpha agonists are a class of drugs used in ophthalmic solutions, to constrict blood vessels (vasoconstriction) in the eyes. Alpha agonist drugs stimulate the activity of protein molecules known as alpha-adrenergic receptors, found on the smooth muscles of blood vessels.

Alpha-adrenergic receptors make muscle around blood vessels contract in response to hormones (catecholamines) epinephrine and norepinephrine released by the adrenal gland. Alpha agonist drugs are known as sympathomimetic drugs, which mimic the effect of catecholamines on the alpha-adrenergic receptors, enabling vasoconstriction.

Alpha agonist eye drops help reduce redness and irritation of the eyes by vasoconstriction of swollen blood vessels in the eye. Some ophthalmic alpha agonists used by ophthalmologists target the contraction of specific eye muscles to dilate the pupils for examination, or to treat droopy eyelids.

How Are Ophthalmic Alpha Agonists Used?

Ophthalmic alpha agonists are used in the following situations:

  • To treat:
    • Irritation or burning caused by dry eyes
    • Redness of the eye from irritation
    • Drooping eyelids (blepharoptosis)
  • To dilate the pupils for examination of the eye or surgery
  • Prevent the iris to adhere to the lens


What causes dry eyes? See Answer

What Are Side Effects of Ophthalmic Alpha Agonists?

Side effects of ophthalmic alpha agonists include:

Rare severe side effects include:

The information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

What Are Names of Some Ophthalmic Alpha Agonist Drugs?

Some Ophthalmic Alpha Agonist Drugs Include:

  • Naphazoline hydrochloride (All Clear, Clear Eyes, Naphcon)
  • Phenylephrine hydrochloride (Altafrin, Neofrin, Refresh Redness Relief)
  • Oxymetazoline hydrochloride (Upneeq)

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