Details of Drug Interaction

Details of Drug-Drug Interaction

 Drug General Information (ID: DDIWCGFAXU)
  Drug Name Rifabutin Drug Info Darunavir Drug Info
  Drug Type Small molecule Small molecule
  Therapeutic Class Antibiotics Antiviral Agents
  Structure

 Mechanism of Rifabutin-Darunavir Interaction (Severity Level: Moderate)
     CYP450 enzyme inhibition Click to Show/Hide Mechanism Graph
Could Not Find 2D Structure
      Drug Name Rifabutin Darunavir
      Mechanism 1 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 Rifabutin caused by Darunavir mediated inhibition of CYP450 enzyme
     CYP450 enzyme induction Click to Show/Hide Mechanism Graph
Could Not Find 2D Structure
      Drug Name Rifabutin Darunavir
      Mechanism 2 CYP450 3A4 inducer CYP450 3A4 substrate
      Key Mechanism Factor 2
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
  • Increased metabolism of Darunavir caused by Rifabutin mediated induction of CYP450 enzyme

Recommended Action
      Management To minimize the risk of rifabutin toxicity including leukopenia, uveitis, arthralgias and skin discoloration, darunavir labeling recommends that rifabutin dosage be reduced to 150 mg every other day in patients treated with darunavir/ritonavir. A complete blood count should be performed at least weekly and as clinically indicated to monitor for development of neutropenia.

References
1 American Thoracic Society, CDC, Infectious Diseases Society of America "Treatment of tuberculosis." MMWR Morb Mortal Wkly Rep 52(RR-11) (2003): 1-77. [PMID: 12836625]
2 Burman WJ, Jones BE "Treatment of HIV-related tuberculosis in the era of effective antiretroviral therapy." Am J Respir Crit Care Med 164 (2001): 7-12. [PMID: 11435232]
3 Cato A, Cavanaugh J, Shi H, Hsu A, Leonard J, Granneman R "The effect of multiple doses of ritonavir on the pharmacokinetics of rifabutin." Clin Pharmacol Ther 63 (1998): 414-21. [PMID: 9585795]
4 Fournier S, Deplus S, Janier M, Poinsignon Y, Decazes JM, Modai J "Anterior uveitis in 3 HIV-infected patients treated with antiprotease." Presse Med 27 (1998): 844-8. [PMID: 9767867]
5 Gariano RF, Gooney EL "Uveitis following administration of the protease inhibitor indinavir to a patient with AIDS." Clin Infect Dis 24 (1997): 529. [PMID: 9114223]
6 Hamzeh FM, Benson C, Gerber J, et al. "Steady-state pharmacokinetic interaction of modified-dose indinavir and rifabutin." Clin Pharmacol Ther 73 (2003): 159-69. [PMID: 12621381]
7 Moyle GJ, Buss NE, Goggin T, Snell P, Higgs C, Hawkins DA "Interaction between saquinavir soft-gel and rifabutin in patients infected with HIV." Br J Clin Pharmacol 54 (2002): 178-82. [PMID: 12207638]
8 Polk RE, Brophy DF, Israel DS, Patron R, Sadler BM, Chittick GE, Symonds WT, Lou Y, Kristoff D, Stein DS "Pharmacokinetic interaction between amprenavir and rifabutin or rifampin in healthy males." Antimicrob Agents Chemother 45 (2001): 502-8. [PMID: 11158747]
9 Product Information. Agenerase (amprenavir). Glaxo Wellcome, Research Triangle Pk, NC.
10 Product Information. Aptivus (tipranavir). Boehringer-Ingelheim, Ridgefield, CT.
11 Product Information. Crixivan (indinavir). Merck & Co, Inc, West Point, PA.
12 Product Information. Fortovase (saquinavir) Roche Laboratories, Nutley, NJ.
13 Product Information. Lexiva (fosamprenavir). GlaxoSmithKline, Research Triangle Park, NC.
14 Product Information. Norvir (ritonavir). Abbott Pharmaceutical, Abbott Park, IL.
15 Product Information. Prezista (darunavir). Ortho Biotech Inc, Bridgewater, NJ.
16 Product Information. Reyataz (atazanavir). Bristol-Myers Squibb, Princeton, NJ.
17 Product Information. Viracept (nelfinavir). Agouron Pharma Inc, La Jolla, CA.
18 Notice to readers: updated guidelines for the use of rifabutin or rifampin for the treatment and prevention of tuberculosis among HIV-infected patients taking protease inhibitors or nonnucleoside reverse transcriptase inhibiotrs. MMWR Morb Mortal Wkly Rep 49 (2000): 185-9. [PMID: 11795500]