Side Effects of Alphagan P (brimonidine)

Alphagan P (brimonidine) is an ophthalmic solution used for the treatment of one type of glaucoma, open-angle glaucoma. 

In this type of glaucoma, too much fluid (aqueous humor) is made within the eye and causes high pressures within the eye. The pressure damages the nerves in the eye responsible for vision, and this ultimately causes blindness. 

Brimonidine reduces the body's production of aqueous humor and increases the flow of aqueous humor out of the eye, resulting in a decrease in pressure. It accomplishes this by stimulating alpha type 2 receptors selectively in the eye with less effect on alpha type 2 receptors elsewhere in the body. It is the first drug of its class to be used for glaucoma. 

Common side effects of Alphagan P include

• dry eyes,
• red eyes,
• eye irritation,
• headache,
• blurred vision,
• feeling something is in the eye, and
• drowsiness.

Other important side effects of Alphagan P include

• corneal staining,
• increased sensitivity to light,
• eyelid redness,
• eye pain,
• tearing,
• eyelid swelling, and
• low blood pressure.

Drug interactions of Alphagan P include other drugs that make you drowsy (opioid medications, sleeping pills, muscle relaxers, or medicines for anxiety or seizures) because taking them with Alphagan P can worsen this effect. Alphagan P may also interact with antidepressants and heart or blood pressure medications. 

There are no adequate and well-controlled studies of Alphagan P in pregnant women. Alphagan P should be used during pregnancy only if the potential benefit to the mother justifies the potential risk to the fetus. 

It is unknown if Alphagan P is secreted in breast milk. Consult your doctor before breastfeeding. 

Common side effects include:

• dry eyes,
• red eyes,
• irritation of the eyes,
• headache,
• blurred vision,
• a sensation of a foreign body in the eye, and
• drowsiness.

Other important side effects of brimonidine include:

• corneal staining,
• increased sensitivity to light,
• eyelid redness,
• eye pain,
• tearing, and
• eyelid swelling, and
• low blood pressure.

Clinical Studies Experience

Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice.

Adverse reactions occurring in approximately 10-20%of the subjects receiving brimonidine ophthalmic solution (0.1-0.2%) included:

• allergic conjunctivitis,
• conjunctival hyperemia, and
• eye pruritus.

Adverse reactions occurring in approximately 5-9% included:

• burning sensation,
• conjunctival folliculosis,
• hypertension,
• ocular allergic reaction,
• oral dryness, and
• visual disturbance.

Adverse reactions occurring in approximately 1-4% of the subjects receiving brimonidine ophthalmic solution (0.1-0.2%) included:

• abnormal taste,
•  allergic reaction,
• asthenia,
• blepharitis,
• blepharoconjunctivitis,
•  blurred vision,
• bronchitis,
• cataract,
• conjunctival edema,
• conjunctival hemorrhage,
• conjunctivitis,
• cough,
• dizziness,
• dyspepsia,
• dyspnea,
• epiphora,
• eye discharge,
• eye dryness,
• eye irritation,
• eye pain,
• eyelid edema,
• eyelid erythema,
• fatigue,
• flu syndrome,
• follicular conjunctivitis,
• foreign body sensation,
• gastrointestinal disorder,
• headache,
• hypercholesterolemia,
•  hypotension,
• infection (primarily colds and respiratory infections),
• insomnia,
• keratitis,
• lid disorder,
• pharyngitis,
• photophobia,
• rash,
•  rhinitis,
• sinus infection,
• sinusitis,
• somnolence,
• stinging,
• superficial punctate keratopathy,
• tearing,
• visual field defect,
• vitreous detachment,
• vitreous disorder,
• vitreous floaters, and
• worsened visual acuity.

The following reactions were reported in less than 1% of subjects:

• corneal erosion,
• hordeolum,
• nasal dryness, and
• taste perversion.

Postmarketing Experience

The following reactions have been identified during postmarketing use of brimonidine tartrate ophthalmic solutions in clinical practice. Because they are reported voluntarily from a population of unknown size, estimates of frequency cannot be made.

The reactions, which have been chosen for inclusion due to either their seriousness, frequency of reporting, possible causal connection to brimonidine tartrate ophthalmic solutions, or a combination of these factors, include:

• bradycardia,
•  depression,
• hypersensitivity,
• iritis,
• keratoconjunctivitis sicca,
• miosis,
• nausea,
• skin reactions (including erythema, eyelid pruritus, rash, and vasodilation),
• syncope, and
• tachycardia.

Apnea, bradycardia, coma, hypotension, hypothermia, hypotonia, lethargy, pallor, respiratory depression, and somnolence have been reported in infants receiving brimonidine tartrate ophthalmic solutions.

• Antihypertensives/Cardiac Glycosides Because Alphagan P (brimonidine tartrate) may reduce blood pressure, caution in using drugs such as antihypertensives and/or cardiac glycosides with Alphagan P (brimonidine tartrate) is advised.

CNS Depressants

• Although specific drug interaction studies have not been conducted with Alphagan P (brimonidine tartrate), the possibility of an additive or potentiating effect with CNS depressants (alcohol, barbiturates, opiates, sedatives, or anesthetics) should be considered.

Tricyclic Antidepressants

• Tricyclic antidepressants have been reported to blunt the hypotensive effect of systemic clonidine.
• It is not known whether the concurrent use of these agents with Alphagan P (brimonidine tartrate) in humans can lead to resulting interference with the IOP lowering effect.
• Caution is advised in patients taking tricyclic antidepressants which can affect the metabolism and uptake of circulating amines.

Monoamine Oxidase Inhibitors

• Monoamine oxidase (MAO) inhibitors may theoretically interfere with the metabolism of brimonidine and potentially result in an increased systemic side-effect such as hypotension. Caution is advised in patients taking MAO inhibitors which can affect the metabolism and uptake of circulating amines.