Drug General Information (ID: DDIIAPY91X)
  Drug Name Tolazamide Drug Info Dabrafenib Drug Info
  Drug Type Small molecule Small molecule
  Therapeutic Class Antidiabetic Agents Multikinase Inhibitors
  Structure

 Mechanism of Tolazamide-Dabrafenib Interaction (Severity Level: Moderate)
     CYP450 enzyme induction Click to Show/Hide Mechanism Graph
Could Not Find 2D Structure
      Drug Name Tolazamide Dabrafenib
      Mechanism CYP450 2C9 substrate CYP450 2C9 inducer
      Key Mechanism Factor 1
Factor Name Cytochrome P450 2C9
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Structure Sequence
MDSLVVLVLCLSCLLLLSLWRQSSGRGKLPPGPTPLPVIGNILQIGIKDISKSLTNLSKVYGPVFTLYFGLKPIVVLHGYEAVKEALIDLGEEFSGRGIFPLAERANRGFGIVFSNGKKWKEIRRFSLMTLRNFGMGKRSIEDRVQEEARCLVEELRKTKASPCDPTFILGCAPCNVICSIIFHKRFDYKDQQFLNLMEKLNENIKILSSPWIQICNNFSPIIDYFPGTHNKLLKNVAFMKSYILEKVKEHQESMDMNNPQDFIDCFLMKMEKEKHNQPSEFTIESLENTAVDLFGAGTETTSTTLRYALLLLLKHPEVTAKVQEEIERVIGRNRSPCMQDRSHMPYTDAVVHEVQRYIDLLPTSLPHAVTCDIKFRNYLIPKGTTILISLTSVLHDNKEFPNPEMFDPHHFLDEGGNFKKSKYFMPFSAGKRICVGEALAGMELFLFLTSILQNFNLKSLVDPKNLDTTPVVNGFASVPPFYQLCFIPV
Gene Name CYP2C9
Uniprot ID CP2C9_HUMAN
KEGG Pathway hsa:1559
Protein Family Cytochrome P450 family
Protein Function
A cytochrome P450 monooxygenase involved in the metabolism of various endogenous substrates, including fatty acids and steroids (PubMed:7574697, PubMed:9866708, PubMed:9435160, PubMed:12865317, PubMed:15766564, PubMed:19965576, PubMed:21576599). Mechanistically, uses molecular oxygen inserting one oxygen atom into a substrate, and reducing the second into a water molecule, with two electrons provided by NADPH via cytochrome P450 reductase (NADPH--hemoprotein reductase) (PubMed:7574697, PubMed:9866708, PubMed:9435160, PubMed:12865317, PubMed:15766564, PubMed:19965576, PubMed:21576599). Catalyzes the epoxidation of double bonds of polyunsaturated fatty acids (PUFA) (PubMed:7574697, PubMed:15766564, PubMed:19965576, PubMed:9866708). Catalyzes the hydroxylation of carbon-hydrogen bonds. Metabolizes cholesterol toward 25-hydroxycholesterol, a physiological regulator of cellular cholesterol homeostasis (PubMed:21576599). Exhibits low catalytic activity for the formation of catechol estrogens from 17beta-estradiol (E2) and estrone (E1), namely 2-hydroxy E1 and E2 (PubMed:12865317). Catalyzes bisallylic hydroxylation and hydroxylation with double-bond migration of polyunsaturated fatty acids (PUFA) (PubMed:9866708, PubMed:9435160). Also metabolizes plant monoterpenes such as limonene. Oxygenates (R)- and (S)-limonene to produce carveol and perillyl alcohol (PubMed:11950794). Contributes to the wide pharmacokinetics variability of the metabolism of drugs such as S-warfarin, diclofenac, phenytoin, tolbutamide and losartan (PubMed:25994031).
    Click to Show/Hide
      Mechanism Description
  • Increased metabolism of Tolazamide caused by Dabrafenib mediated induction of CYP450 enzyme

Recommended Action
      Management Caution is advised when dabrafenib is prescribed to patients with diabetes, particularly those receiving antidiabetic agents that are metabolized by CYP450 3A4 and/or 2C9. Close clinical monitoring of glycemic control is recommended following initiation or discontinuation of dabrafenib, and the dosages of concomitant antidiabetic agents adjusted as necessary. Patients should be advised to notify their physician if their blood glucose is consistently high or if they experience symptoms of severe hyperglycemia such as excessive thirst and increases in the volume or frequency of urination. Likewise, patients should be observed for hypoglycemia when dabrafenib is withdrawn from their therapeutic regimen.

References
1 Cerner Multum, Inc. "Australian Product Information.".
2 Cerner Multum, Inc. "UK Summary of Product Characteristics.".
3 Product Information. Tafinlar (dabrafenib). GlaxoSmithKline, Research Triangle Park, NC.