Details of Drug Interaction

Details of Drug-Drug Interaction

 Drug General Information (ID: DDIOJX7DZK)
  Drug Name Tizanidine Drug Info Apraclonidine Drug Info
  Drug Type Small molecule Small molecule
  Therapeutic Class Analgesics Ophthalmic Glaucoma Agents
  Structure

 Mechanism of Tizanidine-Apraclonidine Interaction (Severity Level: Moderate)
     Additive hypotensive effects Click to Show/Hide Mechanism Graph
Could Not Find 2D Structure
      Drug Name Tizanidine Apraclonidine
      Mechanism Hypotensive effects
Alpha-2 adrenergic receptor  Agonist 		Hypotensive effects
Alpha-2 adrenergic receptor  Agonist
      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 Tizanidine and Apraclonidine 

Recommended Action
      Management Caution is advised if tizanidine is used in combination with topical alpha-2 adrenergic agonists. Close monitoring for development of hypotension is recommended. Patients should be advised to avoid rising abruptly from a sitting or recumbent position, and to notify their physician if they experience dizziness, lightheadedness, syncope, orthostasis, or tachycardia. Patients should also avoid activities requiring mental alertness until they know how these agents affect them.

References
1 Coleman AL, Robin AL, Pollack IP, Rudikoff MT, Enger C, Mayer PR "Cardiovascular and intraocular pressure effects and plasma concentrations of apraclonidine." Arch Ophthalmol 108 (1990): 1264-7. [PMID: 2205182]
2 Product Information. Zanaflex (tizanidine). Acorda Therapeutics, Hawthorne, NY.
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