Abstract
The pharmacokinetics and metabolism of the potent anti-human immunodeficiency virus and anti-hepatitis B virus compound, (-)-cis-5-fluoro-1-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl] cytosine (FTC), were investigated in male CD rats. Plasma clearance of 10 mg of FTC per kg of body weight was biexponential in rats, with a half-life at alpha phase of 4.7 +/- 1.1 min (mean +/- standard deviation) and a half-life at beta phase of 44 +/- 8.8 min (n = 5). The total body clearance of FTC was 1.8 +/- 0.1 liters/h/kg, and the oral bioavailability was 90% +/- 8%. The volume of distribution at steady state (Vss) was 1.5 +/- 0.1 liters/kg. Increasing the dose to 100 mg/kg slowed clearance to 1.5 +/- 0.2 liters/kg/h, lowered the Vss to 1.2 +/- 0.2 liters/kg, and reduced the oral bioavailability to 65% +/- 15%. FTC in the brains of rats was initially less than 2% of the plasma concentration but increased to 6% by 2 h postdose. Probenecid elevated levels of FTC in plasma as well as in brains but did not alter the brain-to-plasma ratio. The urinary and fecal recoveries of unchanged FTC after a 10-mg/kg intravenous dose were 87% +/- 3% and 5% +/- 1.6%, respectively. After a 10-mg/kg oral dose, respective urinary and fecal recoveries were 70% +/- 2.5% and 25% +/- 1.6%. Two sulfoxides of FTC were observed in the urine, accounting for 0.4% +/- 0.03% and 2.7% +/- 0.2% of the intravenous dose and 0.4% +/- 0.06% and 2.5% +/- 0.3% of the oral dose. Also observed were 5-fluorocytosine, representing 0.4% +/- 0.06% of the intravenous dose and 0.4% +/- 0.07% of the oral dose, and FTC glucuronide, representing 0.7% +/- 0.2% of the oral dose and 0.4% +/- 0.2% of the intravenous dose. Neither deaminated FTC nor 5-fluorouracil was observed in the urine (less than 0.2% of dose). The high oral availability and minimal metabolism of FTC encourage its further preclinical development.
Full text
PDF







Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Boudinot F. D., Smith S. G., Funderburg E. D., Schinazi R. F. Pharmacokinetics of 3'-fluoro-3'-deoxythymidine and 3'-deoxy-2',3'-didehydrothymidine in rats. Antimicrob Agents Chemother. 1991 Apr;35(4):747–749. doi: 10.1128/aac.35.4.747. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chang C. N., Doong S. L., Zhou J. H., Beach J. W., Jeong L. S., Chu C. K., Tsai C. H., Cheng Y. C., Liotta D., Schinazi R. Deoxycytidine deaminase-resistant stereoisomer is the active form of (+/-)-2',3'-dideoxy-3'-thiacytidine in the inhibition of hepatitis B virus replication. J Biol Chem. 1992 Jul 15;267(20):13938–13942. [PubMed] [Google Scholar]
- Chatton J. Y., Odone M., Besseghir K., Roch-Ramel F. Renal secretion of 3'-azido-3'-deoxythymidine by the rat. J Pharmacol Exp Ther. 1990 Oct;255(1):140–145. [PubMed] [Google Scholar]
- Coates J. A., Cammack N., Jenkinson H. J., Mutton I. M., Pearson B. A., Storer R., Cameron J. M., Penn C. R. The separated enantiomers of 2'-deoxy-3'-thiacytidine (BCH 189) both inhibit human immunodeficiency virus replication in vitro. Antimicrob Agents Chemother. 1992 Jan;36(1):202–205. doi: 10.1128/aac.36.1.202. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cretton E. M., Schinazi R. F., McClure H. M., Anderson D. C., Sommadossi J. P. Pharmacokinetics of 3'-azido-3'-deoxythymidine and its catabolites and interactions with probenecid in rhesus monkeys. Antimicrob Agents Chemother. 1991 May;35(5):801–807. doi: 10.1128/aac.35.5.801. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Diasio R. B., Lakings D. E., Bennett J. E. Evidence for conversion of 5-fluorocytosine to 5-fluorouracil in humans: possible factor in 5-fluorocytosine clinical toxicity. Antimicrob Agents Chemother. 1978 Dec;14(6):903–908. doi: 10.1128/aac.14.6.903. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Doong S. L., Tsai C. H., Schinazi R. F., Liotta D. C., Cheng Y. C. Inhibition of the replication of hepatitis B virus in vitro by 2',3'-dideoxy-3'-thiacytidine and related analogues. Proc Natl Acad Sci U S A. 1991 Oct 1;88(19):8495–8499. doi: 10.1073/pnas.88.19.8495. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Doshi K. J., Gallo J. M., Boudinot F. D., Schinazi R. F., Chu C. K. Comparative pharmacokinetics of 3'-azido-3'-deoxythymidine (AZT) and 3'-azido-2',3'-dideoxyuridine (AZddU) in mice. Drug Metab Dispos. 1989 Nov-Dec;17(6):590–594. [PubMed] [Google Scholar]
- Eron J. J., Jr, Johnson V. A., Merrill D. P., Chou T. C., Hirsch M. S. Synergistic inhibition of replication of human immunodeficiency virus type 1, including that of a zidovudine-resistant isolate, by zidovudine and 2',3'-dideoxycytidine in vitro. Antimicrob Agents Chemother. 1992 Jul;36(7):1559–1562. doi: 10.1128/aac.36.7.1559. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Furman P. A., Davis M., Liotta D. C., Paff M., Frick L. W., Nelson D. J., Dornsife R. E., Wurster J. A., Wilson L. J., Fyfe J. A. The anti-hepatitis B virus activities, cytotoxicities, and anabolic profiles of the (-) and (+) enantiomers of cis-5-fluoro-1-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl]cytosine. Antimicrob Agents Chemother. 1992 Dec;36(12):2686–2692. doi: 10.1128/aac.36.12.2686. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Galinsky R. E., Flaharty K. K., Hoesterey B. L., Anderson B. D. Probenecid enhances central nervous system uptake of 2',3'-dideoxyinosine by inhibiting cerebrospinal fluid efflux. J Pharmacol Exp Ther. 1991 Jun;257(3):972–978. [PubMed] [Google Scholar]
- Galinsky R. E., Hoesterey B. L., Anderson B. D. Brain and cerebrospinal fluid uptake of zidovudine (AZT) in rats after intravenous injection. Life Sci. 1990;47(9):781–788. doi: 10.1016/0024-3205(90)90550-b. [DOI] [PubMed] [Google Scholar]
- Gerlowski L. E., Jain R. K. Physiologically based pharmacokinetic modeling: principles and applications. J Pharm Sci. 1983 Oct;72(10):1103–1127. doi: 10.1002/jps.2600721003. [DOI] [PubMed] [Google Scholar]
- Hedaya M. A., Sawchuk R. J. Effect of probenecid on the renal and nonrenal clearances of zidovudine and its distribution into cerebrospinal fluid in the rabbit. J Pharm Sci. 1989 Sep;78(9):716–722. doi: 10.1002/jps.2600780903. [DOI] [PubMed] [Google Scholar]
- Holt J. P., Rhode E. A. Similarity of renal glomerular hemodynamics in mammals. Am Heart J. 1976 Oct;92(4):465–472. doi: 10.1016/s0002-8703(76)80046-4. [DOI] [PubMed] [Google Scholar]
- Ibrahim S. S., Boudinot F. D. Pharmacokinetics of 2',3'-dideoxycytidine in rats: application to interspecies scale-up. J Pharm Pharmacol. 1989 Dec;41(12):829–834. doi: 10.1111/j.2042-7158.1989.tb06381.x. [DOI] [PubMed] [Google Scholar]
- Johnson V. A., Merrill D. P., Videler J. A., Chou T. C., Byington R. E., Eron J. J., D'Aquila R. T., Hirsch M. S. Two-drug combinations of zidovudine, didanosine, and recombinant interferon-alpha A inhibit replication of zidovudine-resistant human immunodeficiency virus type 1 synergistically in vitro. J Infect Dis. 1991 Oct;164(4):646–655. doi: 10.1093/infdis/164.4.646. [DOI] [PubMed] [Google Scholar]
- Kelley J. A., Litterst C. L., Roth J. S., Vistica D. T., Poplack D. G., Cooney D. A., Nadkarni M., Balis F. M., Broder S., Johns D. G. The disposition and metabolism of 2',3'-dideoxycytidine, an in vitro inhibitor of human T-lymphotrophic virus type III infectivity, in mice and monkeys. Drug Metab Dispos. 1987 Sep-Oct;15(5):595–601. [PubMed] [Google Scholar]
- Mitsuya H., Broder S. Inhibition of the in vitro infectivity and cytopathic effect of human T-lymphotrophic virus type III/lymphadenopathy-associated virus (HTLV-III/LAV) by 2',3'-dideoxynucleosides. Proc Natl Acad Sci U S A. 1986 Mar;83(6):1911–1915. doi: 10.1073/pnas.83.6.1911. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Motulsky H. J., Ransnas L. A. Fitting curves to data using nonlinear regression: a practical and nonmathematical review. FASEB J. 1987 Nov;1(5):365–374. [PubMed] [Google Scholar]
- Nelson J. A., Vidale E., Enigbokan M. Renal transepithelial transport of nucleosides. Drug Metab Dispos. 1988 Nov-Dec;16(6):789–792. [PubMed] [Google Scholar]
- Niedzwicki J. G., el Kouni M. H., Chu S. H., Cha S. Structure-activity relationship of ligands of the pyrimidine nucleoside phosphorylases. Biochem Pharmacol. 1983 Feb 1;32(3):399–415. doi: 10.1016/0006-2952(83)90517-8. [DOI] [PubMed] [Google Scholar]
- Patel B. A., Chu C. K., Boudinot F. D. Pharmacokinetics and saturable renal tubular secretion of zidovudine in rats. J Pharm Sci. 1989 Jul;78(7):530–534. doi: 10.1002/jps.2600780704. [DOI] [PubMed] [Google Scholar]
- Russell J. W., Whiterock V. J., Marrero D., Klunk L. J. Disposition in animals of a new anti-HIV agent: 2',3'-didehydro-3'-deoxythymidine. Drug Metab Dispos. 1990 Mar-Apr;18(2):153–157. [PubMed] [Google Scholar]
- Schinazi R. F., Chu C. K., Peck A., McMillan A., Mathis R., Cannon D., Jeong L. S., Beach J. W., Choi W. B., Yeola S. Activities of the four optical isomers of 2',3'-dideoxy-3'-thiacytidine (BCH-189) against human immunodeficiency virus type 1 in human lymphocytes. Antimicrob Agents Chemother. 1992 Mar;36(3):672–676. doi: 10.1128/aac.36.3.672. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schinazi R. F., McMillan A., Cannon D., Mathis R., Lloyd R. M., Peck A., Sommadossi J. P., St Clair M., Wilson J., Furman P. A. Selective inhibition of human immunodeficiency viruses by racemates and enantiomers of cis-5-fluoro-1-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl]cytosine. Antimicrob Agents Chemother. 1992 Nov;36(11):2423–2431. doi: 10.1128/aac.36.11.2423. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Soudeyns H., Yao X. I., Gao Q., Belleau B., Kraus J. L., Nguyen-Ba N., Spira B., Wainberg M. A. Anti-human immunodeficiency virus type 1 activity and in vitro toxicity of 2'-deoxy-3'-thiacytidine (BCH-189), a novel heterocyclic nucleoside analog. Antimicrob Agents Chemother. 1991 Jul;35(7):1386–1390. doi: 10.1128/aac.35.7.1386. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ueda K., Tsurimoto T., Nagahata T., Chisaka O., Matsubara K. An in vitro system for screening anti-hepatitis B virus drugs. Virology. 1989 Mar;169(1):213–216. doi: 10.1016/0042-6822(89)90057-3. [DOI] [PubMed] [Google Scholar]
- Unadkat J. D., Wang J. P., Pulham D., Semmes R. L. Dose-ranging pharmacokinetics of zidovudine (azidothymidine) in the rat. Pharm Res. 1989 Aug;6(8):734–736. doi: 10.1023/a:1015954926307. [DOI] [PubMed] [Google Scholar]
- Upton R. A. Simple and reliable method for serial sampling of blood from rats. J Pharm Sci. 1975 Jan;64(1):112–114. doi: 10.1002/jps.2600640123. [DOI] [PubMed] [Google Scholar]
- Wong S. L., Hedaya M. A., Sawchuk R. J. Competitive inhibition of zidovudine clearance by probenecid during continuous coadministration. Pharm Res. 1992 Feb;9(2):228–235. doi: 10.1023/a:1018993524818. [DOI] [PubMed] [Google Scholar]
- Yarchoan R., Perno C. F., Thomas R. V., Klecker R. W., Allain J. P., Wills R. J., McAtee N., Fischl M. A., Dubinsky R., McNeely M. C. Phase I studies of 2',3'-dideoxycytidine in severe human immunodeficiency virus infection as a single agent and alternating with zidovudine (AZT). Lancet. 1988 Jan 16;1(8577):76–81. doi: 10.1016/s0140-6736(88)90283-8. [DOI] [PubMed] [Google Scholar]
- Ziegler D. M. Flavin-containing monooxygenases: catalytic mechanism and substrate specificities. Drug Metab Rev. 1988;19(1):1–32. doi: 10.3109/03602538809049617. [DOI] [PubMed] [Google Scholar]
- de Miranda P., Good S. S., Yarchoan R., Thomas R. V., Blum M. R., Myers C. E., Broder S. Alteration of zidovudine pharmacokinetics by probenecid in patients with AIDS or AIDS-related complex. Clin Pharmacol Ther. 1989 Nov;46(5):494–500. doi: 10.1038/clpt.1989.176. [DOI] [PubMed] [Google Scholar]
