Details of Drug Interaction

Details of Drug-Drug Interaction

 Drug General Information (ID: DDIZ105QMG)
  Drug Name Guanabenz Drug Info Verapamil Drug Info
  Drug Type Small molecule Small molecule
  Therapeutic Class Sympatholytics Analgesics
  Structure

 Mechanism of Guanabenz-Verapamil Interaction (Severity Level: Moderate)
     Additive hypotensive effects Click to Show/Hide Mechanism Graph
Could Not Find 2D Structure
      Drug Name Guanabenz Verapamil
      Mechanism Antihypertensive agent
Alpha-2 adrenergic receptor  Agonist 		Antihypertensive agent
Voltage-gated calcium channel  Blocker
      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.
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      Key Mechanism Factor 2
Factor Name Voltage-dependent L-type calcium channel Structure Sequence
Protein Family Calcium channel beta subunit family
Protein Function
Regulatory subunit of L-type calcium channels (PubMed:1309651, PubMed:8107964, PubMed:15615847). Regulates the activity of L-type calcium channels that contain CACNA1A as pore-forming subunit (By similarity). Regulates the activity of L-type calcium channels that contain CACNA1C as pore-forming subunit and increases the presence of the channel complex at the cell membrane (PubMed:15615847). Required for functional expression L-type calcium channels that contain CACNA1D as pore-forming subunit (PubMed:1309651). Regulates the activity of L-type calcium channels that contain CACNA1B as pore-forming subunit (PubMed:8107964).
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      Mechanism Description
  • Additive hypotensive effects by the combination of Guanabenz and Verapamil 

Recommended Action
      Management Hemodynamic responses should be monitored during coadministration, especially during the first few weeks of therapy. Patients should be advised to take the alpha-blocker at bedtime and to notify their physician if they experience dizziness or syncope while awake.

References
1 McTavish D, Sorkin EM "Verapamil: an updated review of its pharmacodynamic and pharmacokinetic properties, and therapeutic use in hypertension." Drugs 38 (1989): 19-76. [PMID: 2670511]
2 Pasanisi F, Elliot HL, Meredith PA, McSharry DR, Reid JL "Combined alpha adrenoceptor antagonism and calcium channel blockage in normal subjects." Clin Pharmacol Ther 36 (1984): 716-23
3 Kiss I, Farsang C "Nifedipine-prazosin interaction in patients with essential hypertension." Cardiovasc Drugs Ther 3 (1989): 413-5