Details of Drug Interaction | MecDDI

Drug General Information (ID: DDI4Y15G8S)
Drug Name			Repaglinide		Drug Info		Bicalutamide		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Antidiabetic Agents				Antineoplastics
Structure

Mechanism of Repaglinide-Bicalutamide Interaction (Severity Level: Moderate)
CYP450 enzyme inhibition Click to Show/Hide Mechanism Graph

Drug Name		Repaglinide				Bicalutamide
Mechanism		CYP450 3A4 substrate				CYP450 3A4 inhibitor
Key Mechanism Factor 1
		Factor Name		Cytochrome P450 3A4				× Structure Sequence MALIPDLAMETWLLLAVSLVLLYLYGTHSHGLFKKLGIPGPTPLPFLGNILSYHKGFCMFDMECHKKYGKVWGFYDGQQPVLAITDPDMIKTVLVKECYSVFTNRRPFGPVGFMKSAISIAEDEEWKRLRSLLSPTFTSGKLKEMVPIIAQYGDVLVRNLRREAETGKPVTLKDVFGAYSMDVITSTSFGVNIDSLNNPQDPFVENTKKLLRFDFLDPFFLSITVFPFLIPILEVLNICVFPREVTNFLRKSVKRMKESRLEDTQKHRVDFLQLMIDSQNSKETESHKALSDLELVAQSIIFIFAGYETTSSVLSFIMYELATHPDVQQKLQEEIDAVLPNKAPPTYDTVLQMEYLDMVVNETLRLFPIAMRLERVCKKDVEINGMFIPKGVVVMIPSYALHRDPKYWTEPEKFLPERFSKKNKDNIDPYIYTPFGSGPRNCIGMRFALMNMKLALIRVLQNFSFKPCKETQIPLKLSLGGLLQPEKPVVLKVESRDGTVSGA
		Gene Name		CYP3A4
		Uniprot ID		CP3A4_HUMAN
		KEGG Pathway		hsa:1576
		Protein Family		Cytochrome P450 family
		Protein Function		A cytochrome P450 monooxygenase involved in the metabolism of sterols, steroid hormones, retinoids and fatty acids (PubMed:10681376, PubMed:11093772, PubMed:11555828, PubMed:14559847, PubMed:12865317, PubMed:15373842, PubMed:15764715, PubMed:20702771, PubMed:19965576, PubMed:21490593, 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). Catalyzes the hydroxylation of carbon-hydrogen bonds (PubMed:2732228, PubMed:14559847, PubMed:12865317, PubMed:15373842, PubMed:15764715, PubMed:21576599, PubMed:21490593). Exhibits high catalytic activity for the formation of hydroxyestrogens from estrone (E1) and 17beta-estradiol (E2), namely 2-hydroxy E1 and E2, as well as D-ring hydroxylated E1 and E2 at the C-16 position (PubMed:11555828, PubMed:14559847, PubMed:12865317). Plays a role in the metabolism of androgens, particularly in oxidative deactivation of testosterone (PubMed:2732228, PubMed:15373842, PubMed:15764715, PubMed:22773874). Metabolizes testosterone to less biologically active 2beta- and 6beta-hydroxytestosterones (PubMed:2732228, PubMed:15373842, PubMed:15764715). Contributes to the formation of hydroxycholesterols (oxysterols), particularly A-ring hydroxylated cholesterol at the C-4beta position, and side chain hydroxylated cholesterol at the C-25 position, likely contributing to cholesterol degradation and bile acid biosynthesis (PubMed:21576599). Catalyzes bisallylic hydroxylation of polyunsaturated fatty acids (PUFA) (PubMed:9435160). Catalyzes the epoxidation of double bonds of PUFA with a preference for the last double bond (PubMed:19965576). Metabolizes endocannabinoid arachidonoylethanolamide (anandamide) to 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acid ethanolamides (EpETrE-EAs), potentially modulating endocannabinoid system signaling (PubMed:20702771). Plays a role in the metabolism of retinoids. Displays high catalytic activity for oxidation of all-trans-retinol to all-trans-retinal, a rate-limiting step for the biosynthesis of all-trans-retinoic acid (atRA) (PubMed:10681376). Further metabolizes atRA toward 4-hydroxyretinoate and may play a role in hepatic atRA clearance (PubMed:11093772). Responsible for oxidative metabolism of xenobiotics. Acts as a 2-exo-monooxygenase for plant lipid 1,8-cineole (eucalyptol) (PubMed:11159812). Metabolizes the majority of the administered drugs. Catalyzes sulfoxidation of the anthelmintics albendazole and fenbendazole (PubMed:10759686). Hydroxylates antimalarial drug quinine (PubMed:8968357). Acts as a 1,4-cineole 2-exo-monooxygenase (PubMed:11695850). Also involved in vitamin D catabolism and calcium homeostasis. Catalyzes the inactivation of the active hormone calcitriol (1-alpha,25-dihydroxyvitamin D(3)) (PubMed:29461981). Click to Show/Hide
Mechanism Description		Decreased metabolism of Repaglinide caused by Bicalutamide mediated inhibition of CYP450 enzyme

Recommended Action
Management		Because the antidiabetic effect of repaglinide is dose- and concentration-dependent, pharmacologic response to repaglinide should be monitored more closely whenever a CYP450 3A4 inhibitor is added to or withdrawn from therapy. Patients should be advised to regularly monitor their blood sugar and counseled on how to recognize and treat hypoglycemia, which may include symptoms such as headache, dizziness, drowsiness, nervousness, confusion, tremor, hunger, weakness, perspiration, and palpitations.

References
1	Bidstrup TB, Bjornsdottir I, Sidelmann UG, Thomsen MS, Hansen KT "CYP2C8 and CYP3A4 are the principal enzymes involved in the human in vitro biotransformation of the insulin secretagogue repaglinide." Br J Clin Pharmacol 56 (2003): 305-14. [PMID: 12919179]
2	Hatorp V, Hansen KT, Thomsen MS "Influence of drugs interacting with CYP3A4 on the pharmacokinetics, pharmacodynamics, and safety of the prandial glucose regulator repaglinide." J Clin Pharmacol 43 (2003): 649-60. [PMID: 12817528]
3	Khamaisi M, Leitersdorf E "Severe hypoglycemia from clarithromycin-repaglinide drug interaction." Pharmacotherapy 28 (2008): 682-4. [PMID: 18447665]
4	Niemi M, Neuvonen PJ, Kivisto KT "The cytochrome P4503A4 inhibitor clarithromycin increases the plasma concentrations and effects of repaglinide." Clin Pharmacol Ther 70 (2001): 58-65. [PMID: 11452245]
5	Product Information. Prandin (repaglinide). Novo Nordisk Pharmaceuticals Inc, Princeton, NJ.
6	Tornio A, Niemi M, Neuvonen M, et al. "The effect of gemfibrozil on repaglinide pharmacokinetics persists for at least 12 h after the dose: evidence for mechanism-based inhibition of CYP2C8 in vivo." Clin Pharmacol Ther 84 (2008): 403-11. [PMID: 18388877]
7	Niemi M, Backman JT, Neuvonen M, Neuvonen PJ "Effects of gemfibrozil, itraconazole, and their combination on the pharmacokinetics and pharmacodynamics of repaglinide: potentially hazardous interaction between gemfibrozil and repaglinide." Diabetologia 46 (2003): 347-51. [PMID: 12687332]