Zalcitabine Foscarnet

LAMIVUDINE, TENOFOVIR, ZALCITABINE FOSCARNET SODIUM t adverse effects with tenofovir and possibly lamivudine and zalcitabine Uncertain possibly additive toxicity via competition for renal excretion Avoid if possible otherwise monitor FBC and renal function weekly... 

Drugs that may interact with zalcitabine include antacids, chloramphenicol, cisplatin, dapsone, didanosine, disulfiram, ethionamide, glutethimide, gold, hydralazine, iodoquinol, isoniazid, metronidazole, nitrofurantoin, phenytoin, ribavirin, vincristine, cimetidine, metoclopramide, amphotericin, aminoglycosides, foscarnet, antiretroviral nucleoside analogs, pentamidine, and probenecid. 

The sites at which anti-HIV drugs may. in principle, act, are dealt with in detail under a main heading (see ANTIVIRAL agents). In summary, currently, of the drugs actually in use, a number are reverse transcriptase (enzyme) inhibitors (RTIs). Examples of nucleoside RTIs include zidovudine, didanosine and zalcitabine. Some non-nucleoside RTIs include foscarnet sodium, nevirapine, carbovir and TIBO analogues (some of these are at trial stage only). 

No pharmacokinetic interactions occur between foscarnet and di-danosine, zalcitabine or zidovudine. The UK manufacturer does not recommend the concurrent use of lamivudine and foscarnet... 

Intravenous foscarnet 90 mg/kg every 12 hours and oral zalcitabine 750 micrograms every 8 hours were given to 12 HIV-positive subjects for 2 days. There were no clinically significant alterations in the pharmacokinetics of either drug. However, the manufacturers of zalcitabine suggested that the concurrent use of zalcitabine and foscarnet should be well monitored, because foscarnet may possibly decrease the renal elearanee of the zalcitabine, thereby increasing its serum levels and its toxicity, particularly peripheral neuropathy. The antiretroviral effects of foscarnet and zalcitabine were synergistic. ... 

Hivid (Zalcitabine). Roche Pharmaceuticals. US Prescribing information, September 2002. Aweeka FT, Gambertoglio JG, van der Horst C, Raasch R, Jacobson MA. Pharmacokinetics of concomitantiy administered foscarnet and zidovudine for treatment of human immunodeficiency virus irifection (AIDS clinical trials group protocol 053). Antimicrob Agents Chem-other(l992)36,1773-8. 

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