Foscarnet Sodium

일반 설명pyrophosphateanalog that inhibits replication in herpesviruses(CMV, HSV, and VSV) and retroviruses (HIV).Foscarnet(Foscavir) is taken up slowly by the cells and does not undergosignificant intracellular metabolism. Foscarnet is a reversible,noncompetitive inhibitor at the pyrophosphatebindingsite of the viral DNA polymerase and RT. Theultimate effect is inhibition of the cleavage of pyrophosphatefrom deoxynucleotide triphosphates and a cessation ofthe incorporation of nucleoside triphosphates into DNA(with the concomitant release of pyrophosphate).Becausethe inhibition is noncompetitive with respect to nucleosidetriphosphate binding, foscarnet can act synergistically withnucleoside triphosphate antimetabolites (e.g., zidovudineand didanosine triphosphates) in the inhibition of viral DNAsynthesis. Foscarnet does not require bioactivation by viralor cellular enzymes and, hence, can be effective against resistantviral strains that are deficient in virally encoded nucleosidekinases. Foscarnet is a second-line drug for the treatment of retinitiscaused by CMV in patients with AIDS. The drug causesmetabolic abnormalities including increases or decreases inblood Ca2 levels. Nephrotoxicity is common, and this sideeffect precludes the use of foscarnet in other infections causedby herpesvirus or as single-agent therapy for HIV infection.Foscarnet is an excellent ligand for metal ion binding,which undoubtedly contributes to the electrolyte imbalancesobserved with the use of the drug.Hypocalcemia, hypomagnesemia,hypokalemia, and hypophosphatemia and hyperphosphatemiaare observed in patients treated with foscarnet.Side effects such as paresthesias, tetani, seizures, and cardiacarrhythmias may result.