Details of Drug Interaction

Details of Drug-Drug Interaction

 Drug General Information (ID: DDIA6VW4EH)
  Drug Name Verapamil Drug Info Terazosin Drug Info
  Drug Type Small molecule Small molecule
  Therapeutic Class Analgesics Antineoplastics
  Structure

 Mechanism of Verapamil-Terazosin Interaction (Severity Level: Moderate)
     Additive hypotensive effects Click to Show/Hide Mechanism Graph
Could Not Find 2D Structure
      Drug Name Verapamil Terazosin
      Mechanism Antihypertensive agent
Voltage-gated calcium channel  Blocker 		Antihypertensive agent
Alpha-1 adrenergic receptor  Antagonist
      Key Mechanism Factor 1
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).
    Click to Show/Hide
      Key Mechanism Factor 2
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.
    Click to Show/Hide
      Mechanism Description
  • Additive hypotensive effects by the combination of Verapamil and Terazosin 

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