Details of Drug Interaction

Details of Drug-Drug Interaction

 Drug General Information (ID: DDIJS1RTNE)
  Drug Name Carteolol (ophthalmic) Drug Info Guanfacine Drug Info
  Drug Type Small molecule Small molecule
  Therapeutic Class Antihypertensive Agents Antiadrenergic Agents
  Structure

 Mechanism of Carteolol (ophthalmic)-Guanfacine Interaction (Severity Level: Moderate)
     Additive hypotensive effects Click to Show/Hide Mechanism Graph
Could Not Find 2D Structure
      Drug Name Carteolol (ophthalmic) Guanfacine
      Mechanism 1 Antihypertensive agent Antihypertensive agent
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 Carteolol (ophthalmic) and Guanfacine 
      Mechanism 2 Hypotensive effects Antihypertensive agent
Alpha-2 adrenergic receptor  Agonist
      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 Carteolol (ophthalmic) and Guanfacine 
     Increased risk of atrioventricular block Click to Show/Hide Mechanism Graph
Could Not Find 2D Structure
      Drug Name Carteolol (ophthalmic) Guanfacine
      Mechanism 3 Delay atrioventricular conduction Delay atrioventricular conduction
      Key Mechanism Factor 3
Factor Name Atrioventricular block
Factor Description Atrioventricular block is a type of cardiac conduction block that occurs when the electrical signal from the atria to the ventricles is impaired. In an Atrioventricular block, this electrical signal is either delayed or completely blocked. When the signal is completely blocked, the ventricles produce their own electrical signal to control the heart rate. The heart rate produced by the ventricles is much slower than that produced by the sinus node.
      Mechanism Description
  • Increased risk of atrioventricular block by the combination of Carteolol (ophthalmic) and Guanfacine 
     Increased risk of bradycardia Click to Show/Hide Mechanism Graph
Could Not Find 2D Structure
      Drug Name Carteolol (ophthalmic) Guanfacine
      Mechanism 4 Bradycardia Bradycardia
      Key Mechanism Factor 4
Factor Name Bradycardia
Factor Description Bradycardia is a slow heart rate in which the heart beats less than 60 times per minute. If the heart rate is very slow and the heart is not pumping enough oxygen-rich blood to the body, and you may feel dizzy, very tired or weak, and short of breath.
      Mechanism Description
  • Increased risk of bradycardia by the combination of Carteolol (ophthalmic) and Guanfacine 

Recommended Action
      Management Until more information is available, caution and close monitoring of blood pressure are recommended for patients receiving guanfacine with a beta-blocker. Dosage adjustments as well as clinical and laboratory monitoring may be appropriate for some patients. 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, headaches, or reduced or irregular heart rate.

References
1 Product Information. Zanaflex (tizanidine). Acorda Therapeutics, Hawthorne, NY.
2 Bailey RR, Neale TJ "Rapid clonidine withdrawal with blood pressure overshoot exaggerated by beta-blockage." Br Med J 1 (1976): 942-3.[PMID: 5169]
3 Jounela AJ, Lilja M "Interactions between beta-blockers and clonidine." Ann Clin Res 16 (1984): 181-2