Brimonidine Information
Brimonidine ()
Brimonidine () Description
Brimonidine () Tartrate Ophthalmic Solution, 0.2% is a relatively selective alpha-2 adrenergic agonist for ophthalmic use. The chemical name of Brimonidine () tartrate is 5-bromo-6 (2-imidazolidinylideneamino) quinoxaline L-tartrate. It is a white to slightly yellowish powder. In solution, Brimonidine () tartrate has a clear, greenish-yellow color. It has a molecular weight of 442.24 as the tartrate salt and is water soluble (34 mg/mL). The molecular formula is CHBrN•CO; the structural formula is:
Brimonidine () Tartrate Ophthalmic Solution, 0.2% is a sterile ophthalmic solution.
Each mL of Brimonidine () Tartrate Solution contains:
ACTIVE: Brimonidine () Tartrate 2 mg (equivalent to 1.32 mg as Brimonidine () free base).
PRESERVATIVE: Benzalkonium Chloride (0.05 mg)
INACTIVES: Citric Acid, Polyvinyl Alcohol, Sodium Chloride, Sodium Citrate; Hydrochloric Acid and/or Sodium Hydroxide may be added to adjust pH (5.6 to 6.6), and Water for Injection.
Brimonidine () Clinical Pharmacology
Elevated IOP presents a major risk factor in glaucomatous field loss. The higher the level of IOP, the greater the likelihood of optic nerve damage and visual field loss. Brimonidine () Tartrate Ophthalmic Solution has the action of lowering intraocular pressure with minimal effect on cardiovascular and pulmonary parameters.
In comparative clinical studies with timolol 0.5%, lasting up to one year, the IOP lowering effect of Brimonidine () Tartrate Ophthalmic Solution was approximately 4-6 mm Hg compared with approximately 6 mm Hg for timolol. In these studies, both patient groups were dosed BID; however, due to the duration of action of Brimonidine () Tartrate Ophthalmic Solution, it is recommended that Brimonidine () Tartrate Ophthalmic Solution be dosed TID. Eight percent of subjects were discontinued from studies due to inadequately controlled intraocular pressure, which in 30% of these patients occurred during the first month of therapy. Approximately 20% were discontinued due to adverse experiences.
Brimonidine () Indications And Usage
Brimonidine () Tartrate Ophthalmic Solution is indicated for lowering intraocular pressure in patients with open-angle glaucoma or ocular hypertension. The IOP lowering efficacy of Brimonidine () Tartrate Ophthalmic Solution diminishes over time in some patients. This loss of effect appears with a variable time of onset in each patient and should be closely monitored.
Brimonidine () Contraindications
Brimonidine () Tartrate Ophthalmic Solution is contraindicated in patients with hypersensitivity to Brimonidine () tartrate or any component of this medication. It is also contraindicated in patients receiving monoamine oxidase (MAO) inhibitor therapy.
Brimonidine () Precautions
Although Brimonidine () Tartrate Ophthalmic Solution had minimal effect on blood pressure of patients in clinical studies, caution should be exercised in treating patients with severe cardiovascular disease.
Brimonidine () Tartrate Ophthalmic Solution has not been studied in patients with hepatic or renal impairment; caution should be used in treating such patients.
Brimonidine () Tartrate Ophthalmic Solution should be used with caution in patients with depression, cerebral or coronary insufficiency, Raynaud's phenomenon, orthostatic hypotension or thromboangiitis obliterans.
During the studies there was a loss of effect in some patients. The lOP-lowering efficacy observed with Brimonidine () Tartrate Ophthalmic Solution during the first month of therapy may not always reflect the long-term level of IOP reduction. Patients prescribed lOP-lowering medication should be routinely monitored for IOP.
The preservative in Brimonidine () Tartrate Ophthalmic Solution, benzalkonium chloride, may be absorbed by soft contact lenses. Patients wearing soft contact lenses should be instructed to wait at least 15 minutes after instilling Brimonidine () Tartrate Ophthalmic Solution to insert soft contact lenses.
As with other drugs in this class, Brimonidine () Tartrate Ophthalmic Solution may cause fatigue and/or drowsiness in some patients. Patients who engage in hazardous activities should be cautioned of the potential for a decrease in mental alertness.
Although specific drug interaction studies have not been conducted with Brimonidine () Tartrate Ophthalmic Solution, the possibility of an additive or potentiating effect with CNS depressants (alcohol, barbiturates, opiates, sedatives, or anesthetics) should be considered. Alpha-agonists, as a class, may reduce pulse and blood pressure. Caution in using concomitant drugs such as beta-blockers (ophthalmic and systemic): antihypertensives and/or cardiac glycosides is advised.
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 Brimonidine () Tartrate Ophthalmic Solution in humans can lead to resulting interference with I0P lowering effect. No data on the level of circulating catecholamines after Brimonidine () Tartrate Ophthalmic Solution is instilled are available. Caution, however, is advised in patients taking tricyclic antidepressants which can affect the metabolism and uptake of circulating amines.
No compound-related carcinogenic effects were observed in either mice or rats following a 21-month and 24-month study, respectively. In these studies, dietary administration of Brimonidine () tartrate at doses up to 2.5 mg/kg/day in mice and 1.0 mg/kg/day in rats achieved - 77 and 118 times, respectively, the plasma drug concentration estimated in humans treated with one drop of Brimonidine () Tartrate Ophthalmic Solution into both eyes 3 times per day.
Brimonidine () tartrate was not mutagenic or cytogenic in a series of and studies including the Ames test, chromosomal aberration assay in Chinese Hamster Ovary (CHO) cells, a host-mediated assay and cytogenic studies in mice and dominant lethal assay.
Reproductive studies performed in rats with oral doses of 0.66 mg base/kg revealed no evidence of harm to the fetus due to Brimonidine () Tartrate Ophthalmic Solution.
Pregnancy:
Reproduction studies performed in rats with oral doses of 0.66 mg base/kg revealed no evidence of harm to the fetus due to Brimonidine () Tartrate Ophthalmic Solution. Dosing at this level produced 100 times the plasma drug concentration level seen in humans following multiple ophthalmic doses.
There are no adequate and well-controlled studies in pregnant women. In animals studies, Brimonidine () crossed the placenta and entered into the fetal circulation to a limited extent. Brimonidine () Tartrate Ophthalmic Solution should be used during pregnancy only if the potential benefit to the mother justifies the potential risk to the fetus.
In a well-controlled clinical study conducted in pediatric glaucoma patients (ages 2 to 7 years) the most commonly observed adverse events with Brimonidine () tartrate ophthalmic solution 0.2% dosed three times daily were somnolence (50% - 83% in patients ages 2 to 6 years) and decreased alertness. In pediatric patients 7 years of age or older (>20kg), somnolence appears to occur less frequently (25%). The most commonly observed adverse event was somnolence. Approximately 16% of patients on Brimonidine () tartrate ophthalmic solution discontinued from the study due to somnolence.
The safety and effectiveness of Brimonidine () Tartrate Ophthalmic Solution have not been studied in pediatric patients below the age of 2 years. Brimonidine () Tartrate Ophthalmic Solution is not recommended under the age of 2 years (Also refer to ).
Brimonidine () Adverse Reactions
Adverse events occurring in approximately 10-30% of the subjects, in descending order of incidence, included oral dryness, ocular hyperemia: burning and stinging, headache, blurring, foreign body sensation, fatigue/drowsiness, conjunctival follicles, ocular allergic reactions, and ocular pruritus.
Events occurring in approximately 3-9% of the subjects, in descending order included corneal staining/erosion, photophobia, eyelid erythema: ocular ache/pain, ocular dryness, tearing, upper respiratory symptoms, eyelid edema, conjunctival edema, dizziness, blepharitis, ocular irritation gastrointestinal symptoms, asthenia, conjunctival blanching, abnormal vision and muscular pain.
The following adverse reactions were reported in less than 3% of the patients: lid crusting, conjunctival hemorrhage, abnormal taste, insomnia: conjunctival discharge, depression, hypertension, anxiety, palpitations/arrhythmias, nasal dryness and syncope.
The following events have been identified during post-marketing use of Brimonidine () Tartrate Ophthalmic Solution in clinical practice. Because they are reported voluntarily from a population of unknown size, estimates of frequency cannot be made. The events, which have been chosen for inclusion due to either their seriousness, frequency of reporting, causal connection to Brimonidine () Tartrate Ophthalmic Solution, or a combination of these factors, include: bradycardia; hypotension; iritis; miosis; skin reactions (including erythema, eyelid purities, rash, and vasodilation); and tachycardia. Apnea, bradycardia, hypotension, hypothermia, hypotonia, and somnolence have been reported in infants receiving Brimonidine () Tartrate Ophthalmic Solution.
Brimonidine () Overdosage
No information is available on overdosage in humans. Treatment of an oral overdose includes supportive and symptomatic therapy; a patient airway should be maintained.
Brimonidine () Dosage And Administration
The recommended dose is one drop of Brimonidine () Tartrate Ophthalmic Solution in the affected eye(s) three times daily, approximately 8 hours apart.
Brimonidine () Tartrate Ophthalmic Solution may be used concomitantly with other topical ophthalmic drug products to lower intraocular pressure. If more than one topical ophthalmic product is being used, the products should be administered at least 5 minutes apart.
Brimonidine () How Supplied:
Brimonidine () Tartrate Ophthalmic Solution, 0.2% is supplied sterile in white opaque plastic dropper bottles as follows:
Brimonidine ()
Brimonidine ()
