Details of the Drug Combination

General Information of Drug Combination (ID: DCOM1E7)

• Drug Combination Name: Mephenytoin + Tolvaptan
• Indication: Chronic myelogenous leukemia; Status: Investigative [1]
• Component Drugs:
  Mephenytoin (DM5UGDK): Small molecular drug
  Tolvaptan (DMIWFRL): Small molecular drug
• High-throughput Screening Result:
  Testing Cell Line: KBM-7
  Zero Interaction Potency (ZIP) Score: 17.74
  Bliss Independence Score: 17.74
  Loewe Additivity Score: 35.15
  LHighest Single Agent (HSA) Score: 35.15

Molecular Interaction Atlas of This Drug Combination

Indication(s) of Mephenytoin

Disease Entry	ICD 11	Status	REF
Epilepsy	8A60-8A68	Approved	[2]

Mephenytoin Interacts with 1 DTT Molecule(s)

DTT Name	DTT ID	UniProt ID	Mode of Action	REF
Voltage-gated sodium channel alpha Nav1.5 (SCN5A)	TTZOVE0	SCN5A_HUMAN	Blocker	[5]

Mephenytoin Interacts with 9 DME Molecule(s)

DME Name	DME ID	UniProt ID	Mode of Action	REF
Cytochrome P450 3A4 (CYP3A4)	DE4LYSA	CP3A4_HUMAN	Metabolism	[6]
Cytochrome P450 1A2 (CYP1A2)	DEJGDUW	CP1A2_HUMAN	Metabolism	[7]
Cytochrome P450 2D6 (CYP2D6)	DECB0K3	CP2D6_HUMAN	Metabolism	[8]
Cytochrome P450 3A5 (CYP3A5)	DEIBDNY	CP3A5_HUMAN	Metabolism	[6]
Cytochrome P450 2C18 (CYP2C18)	DEZMWRE	CP2CI_HUMAN	Metabolism	[9]
Cytochrome P450 2C8 (CYP2C8)	DES5XRU	CP2C8_HUMAN	Metabolism	[10]
Cytochrome P450 2C9 (CYP2C9)	DE5IED8	CP2C9_HUMAN	Metabolism	[9]
Cytochrome P450 2B6 (CYP2B6)	DEPKLMQ	CP2B6_HUMAN	Metabolism	[11]
Mephenytoin 4-hydroxylase (CYP2C19)	DEGTFWK	CP2CJ_HUMAN	Metabolism	[12]

Mephenytoin Interacts with 1 DOT Molecule(s)

DOT Name	DOT ID	UniProt ID	Mode of Action	REF
Cytochrome P450 2B6 (CYP2B6)	OTOYO4S7	CP2B6_HUMAN	Decreases Methylation	[13]

Indication(s) of Tolvaptan

Disease Entry	ICD 11	Status	REF
Autosomal dominant polycystic kidney disease	GB81	Approved	[3]
Hyponatraemia	5C72	Approved	[4]
Heart failure	BD10-BD13	Phase 3	[4]
Hypernatremia	5C71	Investigative	[3]

Tolvaptan Interacts with 1 DTT Molecule(s)

DTT Name	DTT ID	UniProt ID	Mode of Action	REF
Vasopressin V2 receptor (V2R)	TTK8R02	V2R_HUMAN	Antagonist	[14]

Tolvaptan Interacts with 1 DTP Molecule(s)

DTP Name	DTP ID	UniProt ID	Mode of Action	REF
P-glycoprotein 1 (ABCB1)	DTUGYRD	MDR1_HUMAN	Substrate	[15]

Tolvaptan Interacts with 1 DME Molecule(s)

DME Name	DME ID	UniProt ID	Mode of Action	REF
Cytochrome P450 3A4 (CYP3A4)	DE4LYSA	CP3A4_HUMAN	Metabolism	[16]

Tolvaptan Interacts with 7 DOT Molecule(s)

DOT Name	DOT ID	UniProt ID	Mode of Action	REF
ATP-binding cassette sub-family C member 3 (ABCC3)	OTC3IJV4	MRP3_HUMAN	Decreases Activity	[17]
ATP-binding cassette sub-family C member 4 (ABCC4)	OTO27PAL	MRP4_HUMAN	Decreases Activity	[17]
Bile salt export pump (ABCB11)	OTRU7THO	ABCBB_HUMAN	Decreases Activity	[17]
Cytochrome P450 1A1 (CYP1A1)	OTE4EFH8	CP1A1_HUMAN	Decreases Activity	[18]
Hepatic sodium/bile acid cotransporter (SLC10A1)	OTUJVMCL	NTCP_HUMAN	Decreases Activity	[17]
Cytochrome P450 1B1 (CYP1B1)	OTYXFLSD	CP1B1_HUMAN	Decreases Activity	[18]
ATP-binding cassette sub-family C member 2 (ABCC2)	OTJSIGV5	MRP2_HUMAN	Decreases Activity	[17]

References

• [1] Recurrent recessive mutation in deoxyguanosine kinase causes idiopathic noncirrhotic portal hypertension.Hepatology. 2016 Jun;63(6):1977-86. doi: 10.1002/hep.28499. Epub 2016 Mar 31.
• [2] URL: http://www.guidetopharmacology.org Nucleic Acids Res. 2015 Oct 12. pii: gkv1037. The IUPHAR/BPS Guide to PHARMACOLOGY in 2016: towards curated quantitative interactions between 1300 protein targets and 6000 ligands. (Ligand id: 7223).
• [3] Tolvaptan FDA Label
• [4] URL: http://www.guidetopharmacology.org Nucleic Acids Res. 2015 Oct 12. pii: gkv1037. The IUPHAR/BPS Guide to PHARMACOLOGY in 2016: towards curated quantitative interactions between 1300 protein targets and 6000 ligands. (Ligand id: 2226).
• [5] Lacosamide: a new approach to target voltage-gated sodium currents in epileptic disorders. CNS Drugs. 2009;23(7):555-68.
• [6] Species differences in stereoselective metabolism of mephenytoin by cytochrome P450 (CYP2C and CYP3A). J Pharmacol Exp Ther. 1993 Jan;264(1):89-94.
• [7] Comparison of (S)-mephenytoin and proguanil oxidation in vitro: contribution of several CYP isoforms. Br J Clin Pharmacol. 1999 Aug;48(2):158-67.
• [8] Ethnic differences in genetic polymorphisms of CYP2D6, CYP2C19, CYP3As and MDR1/ABCB1. Drug Metab Pharmacokinet. 2004 Apr;19(2):83-95.
• [9] Cytochrome P450 metabolic dealkylation of nine N-nitrosodialkylamines by human liver microsomes. Carcinogenesis. 1996 Sep;17(9):2029-34.
• [10] Evidence that CYP2C19 is the major (S)-mephenytoin 4'-hydroxylase in humans. Biochemistry. 1994 Feb 22;33(7):1743-52.
• [11] Substrates, inducers, inhibitors and structure-activity relationships of human Cytochrome P450 2C9 and implications in drug development. Curr Med Chem. 2009;16(27):3480-675.
• [12] Cytochromes P450 mediating the N-demethylation of amitriptyline. Br J Clin Pharmacol. 1997 Feb;43(2):137-44.
• [13] Evaluation of cytochrome P450 probe substrates commonly used by the pharmaceutical industry to study in vitro drug interactions. Drug Metab Dispos. 2002 Dec;30(12):1311-9.
• [14] Antibody-mediated disruption of the interaction between PCSK9 and the low-density lipoprotein receptor. Biochem J. 2009 May 1;419(3):577-84.
• [15] In vitro P-glycoprotein interactions and steady-state pharmacokinetic interactions between tolvaptan and digoxin in healthy subjects. J Clin Pharmacol. 2011 May;51(5):761-9.
• [16] Tolvaptan: a new therapeutic agent. Rev Recent Clin Trials. 2011 May;6(2):177-88.
• [17] Inhibition of Human Hepatic Bile Acid Transporters by Tolvaptan and Metabolites: Contributing Factors to Drug-Induced Liver Injury?. Toxicol Sci. 2016 Jan;149(1):237-50. doi: 10.1093/toxsci/kfv231. Epub 2015 Oct 26.
• [18] Association of CYP1A1 and CYP1B1 inhibition in in vitro assays with drug-induced liver injury. J Toxicol Sci. 2021;46(4):167-176. doi: 10.2131/jts.46.167.