Page 27 - FPGEE Medicinal and Organic Chemistry Q&A Book

Krisman

Cidofovir is an injectable antiviral medication N N
for the treatment of cytomegalovirus (CMV)
retinitis in patients with AIDS. It suppresses NH 2 N N
CMV replication by selective inhibition of viral CH 3 COO CH 2
DNA synthesis. Nephrotoxicity is the major side CH CH 2 CH 2
effect of the drug. CH 3 COO CH 2
Famciclovir
271. (c) Foscarnet Na (Foscavir) or Hydrolysis Oxidation
phosphonomethanoic acid is a phosphonic acid
O
derivative. It is an antiviral medication used to
treat herpes viruses, including cytomegalovirus N
HN
(CMV) and herpes simplex viruses types 1 and
2 (HSV-1 and HSV-2). It is particularly used to NH 2 N N
treat CMV retinitis. Nephrotoxicity, severe elec- H O CH 2
trolytes imbalances and genital ulceration are CH CH 2 CH 2
reported side effects of the drug. Increase in H O CH 2
serum creatinine levels occurs on average in Penciclovir
45% of patients receiving foscarnet. Other neph- O
rotoxic drugs should be avoided. Nephrotoxicity N
HN
is usually reversible and can be reduced by dos-
age adjustment and adequate hydration. NH 2 N N
Changes in calcium, magnesium, potassium and
CH
O
H
2
phosphate levels occur commonly, and regular CH O CH
2
monitoring of electrolytes is necessary to avoid H O CH 2
clinical toxicity.
Ganciclovir
272. (d) Famciclovir (Famvir) is a synthetic 273. (b) Ribavirin (Copegus, Rebetol, Virazole)
purine nucleoside analogue related to guanine. is an anti-viral drug. Ribavirin is a pro-drug,
It is the diacetyl 6-deoxy ester of penciclovir. meaning that it is a chemical precursor for the
Its pharmacological and microbiological activi- actual pharmacologically active molecule.
ties are similar to acyclovir. Famciclovir is a When the pro-drug is administered, the body
prodrug of penciclovir which is formed by hy- converts it into the desired chemical. Ribavirin
drolysis of the acetyl groups and oxidation at is activated by cellular kinases which change it
the 6th position by mixed function oxidase. into the 5' triphosphate nucleotide. In this form
Famciclovir is indicated for the treatment of it interferes with aspects of RNA metabolism
recurrent localized herpes zoster and genital related to viral replication.
herpes in immunocompetent adults. Penciclovir, It is indicated for the treatment of
a prodrug of Famciclovir, is structurally simi- hepatitis C, in combination with pegylated
lar to ganciclovir. interferon drugs. Hemolytic anemia is the ma-
jor side effect of the drug.
Triazole refers to either one of a pair of
isomeric chemical compounds with molecular
formula C H N , having a five-membered ring
2 3 3
of two carbon atoms and three nitrogen atoms.
There are two isomers:

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