Brimonidine, a vasoconstrictor treatment for rosacea.

Brimonidine is a highly selective agonist of post-synaptic α2-adrenergic receptors. By binding to these receptors at the level of the cells of the blood vessels, brimonidine will exert a vasoconstrictive action on human subcutaneous blood vessels. As a result, the blood flow to the face is reduced, which will contribute to the attenuation of redness and visible blood capillaries.

Brimonidine is metabolised by the liver and the primary route of elimination for brimonidine and its metabolites is urinary excretion.

Brimonidine is typically presented in the form of a topical application gel. The dosage of brimonidine to be adhered to depends on the care product used. However, for an adult over 18 years old, the recommended dose is approximately 1 gram of gel (equivalent to a small pea) to be applied once a day in a thin layer on the various areas of the face (forehead, chin, nose and cheeks).

It is crucial not to exceed the recommended dosage and frequency of application.

The side effects listed below are not experienced by everyone who takes this medication. However, it is appropriate to stop using the product as soon as any of these side effects appear and consult your doctor.

• Common local reactions: congestive flushes, skin redness, itching, burning sensation;

• Infrequent local reactions: skin irritation, exacerbation of rosacea, sensation of heat or skin discomfort, dry skin, acne, hives, facial swelling;

• Other reactions: headaches (possibly related to the highly lipophilic nature of brimonidine, which facilitates its passage through the blood-brain barrier, thus increasing the likelihood of side effects on the central nervous system), tingling, eyelid swelling, blocked nose, dry mouth, sensation of cold feet and hands, allergic reaction (Quincke's oedema).

Allergic reactions can also occur. If in any doubt, consult your doctor or pharmacist for more information.

The treatment containing brimonidine should be used exclusively on the face, only on the affected areas. Ensure not to apply it on open wounds to avoid complications, or on irritated skin. Remember to wash your hands after application and wait for the gel to dry on your face before using other products.

When applying, take care to avoid touching the eyes. Also avoid sensitive areas such as the eyelids, mouth, and nasal mucosa. In case of contact, rinse thoroughly with water.

The use of a treatment containing brimonidine should be avoided by pregnant and breastfeeding women, as the effect of this substance in these situations is still not well understood. However, consult a doctor to understand the risks associated with the use of brimonidine in your case. Due to the lack of data on the safety of brimonidine in children, this medication should not be used in children under two years of age.

Its use should be avoided in individuals taking certain antidepressants, particularly those from the MAOI family (Monoamine Oxidase Inhibitors). Indeed, MAOIs can interfere with the metabolism of brimonidine and increase the intensity of a systemic side effect, such as hypotension.

Precautions are also necessary for individuals suffering from cardiovascular diseases, Raynaud's phenomenon,hypotension orthostatic or depression, because α2-adrenergic agonists can lower blood pressure.