Details of Drug Interaction | MecDDI

Drug General Information (ID: DDIOHAWFL3)
Drug Name			Apraclonidine		Drug Info		Terazosin		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Ophthalmic Glaucoma Agents				Antineoplastics
Structure

Mechanism of Apraclonidine-Terazosin Interaction (Severity Level: Moderate)
Additive hypotensive effects Click to Show/Hide Mechanism Graph

Drug Name		Apraclonidine				Terazosin
Mechanism		Hypotensive effects Alpha-2 adrenergic receptor Agonist				Antihypertensive agent Alpha-1 adrenergic receptor Antagonist
Key Mechanism Factor 1
		Factor Name		Adrenergic receptor alpha-2				Structure Sequence
		Protein Family		G-protein coupled receptor 1 family
		Protein Function		Alpha-2 adrenergic receptors mediate the catecholamine-induced inhibition of adenylate cyclase through the action of G proteins. The rank order of potency for agonists of this receptor is oxymetazoline > clonidine > epinephrine > norepinephrine > phenylephrine > dopamine > p-synephrine > p-tyramine > serotonin = p-octopamine. For antagonists, the rank order is yohimbine > phentolamine = mianserine > chlorpromazine = spiperone = prazosin > propanolol > alprenolol = pindolol. Click to Show/Hide
Key Mechanism Factor 2
		Factor Name		Adrenergic receptor alpha-1				Structure Sequence
		Protein Family		G-protein coupled receptor 1 family
		Protein Function		This alpha-adrenergic receptor mediates its action by association with G proteins that activate a phosphatidylinositol-calcium second messenger system. Its effect is mediated by G(q) and G(11) proteins. Nuclear ADRA1A-ADRA1B heterooligomers regulate phenylephrine(PE)-stimulated ERK signaling in cardiac myocytes. Click to Show/Hide
Mechanism Description		Additive hypotensive effects by the combination of Apraclonidine and Terazosin

Recommended Action
Management		Blood pressure and pulse rate should be monitored regularly when topical alpha-2 adrenergic receptor agonists are prescribed in combination with cardiovascular drugs. Patients should be advised to notify their physician if they experience slow pulse, irregular heartbeat, dizziness, lightheadedness, or syncope.

References
1	Product Information. Alphagan (brimonidine ophthalmic). Allergan Inc, Irvine, CA.
2	Product Information. Mirvaso (brimonidine topical). Galderma Laboratories Inc, Cranbury, NJ.
3	Walters TR "Development and use of brimonidine in treating acute and chronic elevations of intraocular pressure: a review of safety, efficacy, dose response, and dosing studies." Surv Ophthalmol 41 ( Suppl (1996): s19-26