Brimonidineinteractions

7 D RUG INTERACTIONS Antihypertensives/cardiac glycosides may lower blood pressure. Concomitant use with systemic beta-blockers may potentiate systemic beta blockade. Oral or intravenous calcium antagonists may cause atrioventricular conduction disturbances, left ventricular failure, and hypotension. Catecholamine-depleting drugs may have additive effects and produce hypotension and/or marked bradycardia. Use with CNS depressants may result in an additive or potentiating effect. Digitalis and calcium antagonists may have additive effects in prolonging atrioventricular conduction time. CYP2D6 inhibitors may potentiate systemic beta-blockade. Tricyclic antidepressants may potentially blunt the hypotensive effect of systemic clonidine. Monoamine oxidase inhibitors may result in increased hypotension.

7.1 Antihypertensives/Cardiac

Glycosides Because COMBIGAN may reduce blood pressure, caution in using drugs such as antihypertensives and/or cardiac glycosides with COMBIGAN is advised.

7.2 Beta-adrenergic

Blocking Agents Patients who are receiving a beta-adrenergic blocking agent either orally or intravenously and COMBIGAN should be observed for potential additive effects of beta-blockade, both systemic and on intraocular pressure. The concomitant use of two topical beta-adrenergic blocking agents is not recommended.

7.3 Calcium

Antagonists Caution should be used in the co-administration of beta-adrenergic blocking agents, such as COMBIGAN, and oral or intravenous calcium antagonists because of possible atrioventricular conduction disturbances, left ventricular failure, and hypotension. In patients with impaired cardiac function, co-administration should be avoided.

7.4 Catecholamine-depleting

Drugs Close observation of the patient is recommended when a beta blocker is administered to patients receiving catecholamine-depleting drugs such as reserpine, because of possible additive effects and the production of hypotension and/or marked bradycardia, which may result in vertigo, syncope, or postural hypotension.

7.5 CNS Depressants

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

7.6 Digitalis and

Calcium Antagonists The concomitant use of beta-adrenergic blocking agents with digitalis and calcium antagonists may have additive effects in prolonging atrioventricular conduction time.

7.7 CYP2D6 Inhibitors

Potentiated systemic beta-blockade (e.g., decreased heart rate, depression) has been reported during combined treatment with CYP2D6 inhibitors (e.g., quinidine, SSRIs) and timolol.

7.8 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 COMBIGAN in humans can lead to resulting interference with the IOP-lowering effect. Caution, however, is advised in patients taking tricyclic antidepressants which can affect the metabolism and uptake of circulating amines.

7.9 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, however, is advised in patients taking MAO inhibitors which can affect the metabolism and uptake of circulating amines.