Brimonidine is a medication primarily used to treat open-angle glaucoma or ocular hypertension. It belongs to a class of drugs called alpha agonists, which work by reducing the production of aqueous humor (the fluid in the eye) to lower intraocular pressure. Lowering intraocular pressure helps prevent optic nerve damage and vision loss associated with these eye conditions. Brimonidine is often administered as eye drops.

Brimonidine is an alpha-2 receptor agonist that causes vasoconstriction when applied topically to the skin.  It is used as a topical treatment of persistent erythema of Rosaceae in adults. It is also used to treat open-angle glaucoma and ocular hypertension.

Brimonidine Dose in Adults

Brimonidine Use in the treatment of Rosacea:  

• When using brimonidine for rosacea, you apply a small amount, about the size of a pea, once a day.
• Gently spread it in a thin layer across your whole face, including your forehead, cheeks, nose, and chin.
• This helps reduce redness and improve the appearance of your skin.

Brimonidine Use in the treatment of open-angle glaucoma:

• Instill one drop in the affected eye three times a day.

Brimonidine Dose in Children

Not recommended. It is contraindicated in neonates and infants.

Pregnancy Risk Factor B

• Brimonidine has been categorized as Pregnancy Risk Factor B, indicating that studies on animals haven't shown any adverse effects on reproduction.
• This classification suggests that there's no evidence to suggest harm to the fetus based on animal studies, but there may not be enough human studies to confirm its safety during pregnancy.

Breastfeeding:

• The excretion of brimonidine into breast milk is not fully understood.
• Due to the possibility of serious adverse effects in nursing infants, the manufacturer advises considering whether to discontinue breastfeeding or stop taking the medication, taking into account the importance of treatment for the mother's health.

Brimonidine Dose in Renal Disease:

• According to the manufacturer's recommendations, no dose adjustments are typically necessary for patients with kidney disease when using brimonidine.

Brimonidine Dose in Liver Disease:

• According to the manufacturer's guidelines, no dose adjustments are typically recommended for patients with liver disease when using brimonidine.

Common Side Effects of Brimonidine Innclude:

• Cardiovascular:
  • Flushing
• Central Nervous System:
  • Burning Sensation Of Skin
  • Localized Warm Feeling
  • Paresthesia
• Dermatologic:
  • Erythema
  • Acne Vulgaris
  • Allergic Contact Dermatitis
  • Contact Dermatitis
  • Dermatitis
  • Skin Pain
• Ophthalmic:
  • Blurred vision
• Respiratory:
  • Nasal congestion

Contraindication to Brimonidine include:

• Hypersensitivity to brimonidine or any ingredient in the formulation is a contraindication for its use.
• In Canadian labeling, there are additional contraindications not present in the US labeling, which include the use of brimonidine in neonates and infants under the age of two years.

Warnings and Precautions

Erythema

• Erythema, or redness of the skin, is a potential side effect of using brimonidine gel.
• Interestingly, the effectiveness of the gel may decrease within hours of application, and in some cases, redness can reappear or even worsen compared to the baseline, either within or outside of the treatment areas.
• However, these symptoms typically resolve once the therapy is discontinued.

Flushing

• Flushing, characterized by temporary redness and warmth of the skin, can occur intermittently, with increased frequency or as a new occurrence, roughly 30 minutes to several hours after applying brimonidine gel.
• However, these symptoms typically resolve once the therapy is discontinued.

Hypersensitivity

• Hypersensitivity reactions to brimonidine gel can manifest as allergic contact dermatitis, characterized by skin irritation and inflammation.
• In more severe cases, angioedema (swelling beneath the skin), throat tightening, tongue swelling, and hives (urticaria) may occur.
• If significant hypersensitivity reactions are experienced, it's crucial to discontinue the use of the gel and seek medical attention promptly.

Pallor:

• Pallor, or excessive whitening of the skin, has been observed either at the treatment areas or outside of them in some cases when using brimonidine gel.

Systemic effects

• Systemic effects such as bradycardia (slow heart rate), hypotension (low blood pressure), including orthostatic hypotension (a sudden drop in blood pressure upon standing), and dizziness have been reported with the use of brimonidine gel.
• These effects can be severe and may necessitate hospitalization.
• It's important to note that these systemic effects may occur when brimonidine gel is used in unapproved dosing or for indications not specified in its labeling, such as use after laser procedures.

Cardiovascular disease

• Brimonidine gel may lower blood pressure, so caution is advised when using it in patients with orthostatic hypotension or those with severe, unstable, or uncontrolled cardiovascular disease.
• Additionally, there's a potential for brimonidine to potentiate vascular insufficiency, so it should be used cautiously in individuals with conditions such as cerebral or coronary insufficiency, scleroderma, thromboangiitis obliterans, and Raynaud phenomenon.

Depression

• Caution is advised when using brimonidine gel in patients with depression.

Sjogren syndrome:

• Caution should be exercised when using brimonidine gel in patients with Sjögren syndrome.

Monitoring Parameters:

None required.

How to administer Brimonidine?

• Application Method: Smoothly and evenly apply a thin layer of brimonidine gel across your entire face, including the central forehead, each cheek, nose, and chin.
• Avoid Sensitive Areas: Be careful to avoid the eyes and lips when applying the gel.
• Hand Hygiene: Wash your hands immediately after applying the gel to prevent accidental transfer to other areas.
• Avoid Open Wounds: Do not apply brimonidine gel to open wounds or irritated skin, as it may cause discomfort or exacerbate existing irritation.

Mechanism of action of Brimonidine:

• Brimonidine is a type of medication that acts mainly on alpha receptors in the body.
• When applied on the skin, it can help reduce redness by causing the blood vessels to constrict directly.
• This action makes it effective in decreasing erythema, or redness, by narrowing the blood vessels, which reduces the amount of blood flow to the skin.

Metabolism:

• Brimonidine gel is metabolized in the liver.

Time to Peak:

• Maximum plasma concentrations are typically observed after 15 days of regular use.

Excretion:

• The body eliminates brimonidine primarily through urine.

International brands of Brimonidine:

• Mirvaso
• Onreltea

Brimonidine brands in Pakistan: