Details of Drug Interaction | MecDDI

Drug General Information (ID: DDIJQ96ADB)
Drug Name			Guanabenz		Drug Info		Amifostine		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Sympatholytics				Cytoprotective Agent
Structure

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

Drug Name		Guanabenz				Amifostine
Mechanism 1		Antihypertensive agent Alpha-2 adrenergic receptor Agonist				Antihypertensive agent
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
Mechanism Description		Additive hypotensive effects by the combination of Guanabenz and Amifostine
Mechanism 2		Antihypertensive agent Alpha-2 adrenergic receptor Agonist				Hypotensive effects
Key Mechanism Factor 2
		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
Mechanism Description		Additive hypotensive effects by the combination of Guanabenz and Amifostine

Recommended Action
Management		If medically feasible, antihypertensive medications should be interrupted 24 hours prior to amifostine administration. Blood pressure should be closely monitored during and after treatment. In addition to hypotension, transient hypertension or exacerbation of preexisting hypertension may occur from intravenous hydration, discontinuation of antihypertensive medications, or other causes. Patients who continue their hypotensive medication(s) during amifostine therapy should be carefully monitored for the development of hypotension.

References
1	Bailey DG, Dresser GK "Natural products and adverse drug interactions." Can Med Assoc J 170 (2004): 1531-2. [PMID: 15136542]
2	Product Information. Xatral (alfuzosin). Sanofi-Synthelabo Canada Inc, Markham, ON.
3	Product Information. Ethyol (amifostine). Alza, Palo Alto, CA.