Details of Drug Interaction

Details of Drug-Drug Interaction

 Drug General Information (ID: DDIWTEYI5L)
  Drug Name Alfuzosin Drug Info Tizanidine Drug Info
  Drug Type Small molecule Small molecule
  Therapeutic Class Antihypertensive Agents Analgesics
  Structure

 Mechanism of Alfuzosin-Tizanidine Interaction (Severity Level: Moderate)
     Additive hypotensive effects Click to Show/Hide Mechanism Graph
Could Not Find 2D Structure
      Drug Name Alfuzosin Tizanidine
      Mechanism 1 Hypotensive effects
Alpha-1 adrenergic receptor  Antagonist 		Hypotensive effects
Alpha-2 adrenergic receptor  Agonist
      Key Mechanism Factor 1
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.
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      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.
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      Mechanism Description
  • Additive hypotensive effects by the combination of Alfuzosin and Tizanidine 
     Increased risk of prolong QT interval Click to Show/Hide Mechanism Graph
Could Not Find 2D Structure
      Drug Name Alfuzosin Tizanidine
      Mechanism 2 Prolong QT interval Prolong QT interval
      Key Mechanism Factor 3
Factor Name QT interval
Factor Description Long QT syndrome is a heart signaling disorder that can cause a fast, chaotic heartbeat (arrhythmia). Many people may not exhibit symptoms, and usually the condition is detected during routine medical tests. In others, the most common symptoms include: sudden fainting, palpitations, dizziness, seizures, sudden death.
      Mechanism Description
  • Increased risk of prolong QT interval by the combination of Alfuzosin and Tizanidine 

Recommended Action
      Management Caution and clinical monitoring are recommended during concurrent therapy. Patients should be advised to notify their physician if they experience orthostatic symptoms (e.g., lightheadedness, dizziness, syncope) and to seek medical help if they experience palpitations, or irregular heartbeats.

References
1 Product Information. Uroxatral (alfuzosin). sanofi-aventis , Bridgewater, NJ.
2 Product Information. Zanaflex (tizanidine). Acorda Therapeutics, Hawthorne, NY.