Drug General Information (ID: DDIZCJ0QWD)
  Drug Name Methylphenobarbital Drug Info Rifampicin Drug Info
  Drug Type Small molecule Small molecule
  Therapeutic Class Anxiolytics/Sedatives/Hypnotics Antituberculosis Agents
  Structure

 Mechanism of Methylphenobarbital-Rifampicin Interaction (Severity Level: Minor)
     CYP450 enzyme induction Click to Show/Hide Mechanism Graph
Could Not Find 2D Structure
      Drug Name Methylphenobarbital Rifampicin
      Mechanism 1 CYP450 2B6 substrate CYP450 2B6 inducer
      Key Mechanism Factor 1
Factor Name Cytochrome P450 2B6
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Structure Sequence
MELSVLLFLALLTGLLLLLVQRHPNTHDRLPPGPRPLPLLGNLLQMDRRGLLKSFLRFREKYGDVFTVHLGPRPVVMLCGVEAIREALVDKAEAFSGRGKIAMVDPFFRGYGVIFANGNRWKVLRRFSVTTMRDFGMGKRSVEERIQEEAQCLIEELRKSKGALMDPTFLFQSITANIICSIVFGKRFHYQDQEFLKMLNLFYQTFSLISSVFGQLFELFSGFLKYFPGAHRQVYKNLQEINAYIGHSVEKHRETLDPSAPKDLIDTYLLHMEKEKSNAHSEFSHQNLNLNTLSLFFAGTETTSTTLRYGFLLMLKYPHVAERVYREIEQVIGPHRPPELHDRAKMPYTEAVIYEIQRFSDLLPMGVPHIVTQHTSFRGYIIPKDTEVFLILSTALHDPHYFEKPDAFNPDHFLDANGALKKTEAFIPFSLGKRICLGEGIARAELFLFFTTILQNFSMASPVAPEDIDLTPQECGVGKIPPTYQIRFLPR
Gene Name CYP2B6
Uniprot ID CP2B6_HUMAN
KEGG Pathway hsa:1555
Protein Family Cytochrome P450 family
Protein Function
A cytochrome P450 monooxygenase involved in the metabolism of endocannabinoids and steroids (PubMed:21289075, PubMed:12865317). 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). Catalyzes the epoxidation of double bonds of arachidonoylethanolamide (anandamide) to 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acid ethanolamides (EpETrE-EAs), potentially modulating endocannabinoid system signaling (PubMed:21289075). Hydroxylates steroid hormones, including testosterone at C-16 and estrogens at C-2 (PubMed:21289075, PubMed:12865317). Plays a role in the oxidative metabolism of xenobiotics, including plant lipids and drugs (PubMed:11695850, PubMed:22909231). Acts as a 1,4-cineole 2-exo-monooxygenase (PubMed:11695850).
    Click to Show/Hide
      Mechanism Description
  • Increased metabolism of Methylphenobarbital caused by Rifampicin mediated induction of CYP450 enzyme
      Mechanism 2 CYP450 2C19 substrate CYP450 2C19 inducer
      Key Mechanism Factor 2
Factor Name Cytochrome P450 2C19
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Structure Sequence
MDPFVVLVLCLSCLLLLSIWRQSSGRGKLPPGPTPLPVIGNILQIDIKDVSKSLTNLSKIYGPVFTLYFGLERMVVLHGYEVVKEALIDLGEEFSGRGHFPLAERANRGFGIVFSNGKRWKEIRRFSLMTLRNFGMGKRSIEDRVQEEARCLVEELRKTKASPCDPTFILGCAPCNVICSIIFQKRFDYKDQQFLNLMEKLNENIRIVSTPWIQICNNFPTIIDYFPGTHNKLLKNLAFMESDILEKVKEHQESMDINNPRDFIDCFLIKMEKEKQNQQSEFTIENLVITAADLLGAGTETTSTTLRYALLLLLKHPEVTAKVQEEIERVIGRNRSPCMQDRGHMPYTDAVVHEVQRYIDLIPTSLPHAVTCDVKFRNYLIPKGTTILTSLTSVLHDNKEFPNPEMFDPRHFLDEGGNFKKSNYFMPFSAGKRICVGEGLARMELFLFLTFILQNFNLKSLIDPKDLDTTPVVNGFASVPPFYQLCFIPV
Gene Name CYP2C19
Uniprot ID CP2CJ_HUMAN
KEGG Pathway hsa:1557
Protein Family Cytochrome P450 family
Protein Function
A cytochrome P450 monooxygenase involved in the metabolism of polyunsaturated fatty acids (PUFA) (PubMed:18577768, PubMed:19965576, PubMed:20972997). 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:18577768, PubMed:19965576, PubMed:20972997). Catalyzes the hydroxylation of carbon-hydrogen bonds. Hydroxylates PUFA specifically at the omega-1 position (PubMed:18577768). Catalyzes the epoxidation of double bonds of PUFA (PubMed:20972997, PubMed:19965576). Also metabolizes plant monoterpenes such as limonene. Oxygenates (R)- and (S)-limonene to produce carveol and perillyl alcohol (PubMed:11950794). Responsible for the metabolism of a number of therapeutic agents such as the anticonvulsant drug S-mephenytoin, omeprazole, proguanil, certain barbiturates, diazepam, propranolol, citalopram and imipramine. Hydroxylates fenbendazole at the 4' position (PubMed:23959307).
    Click to Show/Hide
      Mechanism Description
  • Increased metabolism of Methylphenobarbital caused by Rifampicin mediated induction of CYP450 enzyme

References
1 Richter E, Breimer DD, Zilly W "Disposition of hexobarbital in intra- and extrahepatic cholestasis in man and the influence of drug metabolism-inducing agents." Eur J Clin Pharmacol 17 (1980): 197-202. [PMID: 7363932]
2 Breimer DD, Zilly W, Richter E. Influence of rifampicin on drug metabolism: differences between hexobarbital and antipyrine.?Clin Pharmacol Ther. 1977;21(4):470-481. [PMID: 849678]
3 Venkatesan K "Pharmacokinetic drug interactions with rifampicin." Clin Pharmacokinet 22 (1992): 47-65. [PMID: 1559307]