Retrovir is the brand name for one form of the drug zidovudine, or
AZT, that is put out by Glaxo Wellcome Inc. It comes in tablet, capsule,
syrup, and IV use forms. Zidovudine is a pyrimidine nucleoside analogue
that is active against HIV.
Mechanism
When in the body, Retrovir is phosphorylated to an active
form which inhibits the activity of HIV reverse transcriptase by
competing with dTTP for utilization in reverse transcription and
by incorporating itself into the viral DNA, terminating DNA
growth.
Indications
Retrovir is indicated for cases where antiretorviral therapy
can be beneficial. This includes prevention of HIV transmission from
mother to fetus and as part of combination treatment of adults with HIV
disease.
Usage/Dosage
For prevention of maternal-fetal HIV transmission, Retrovir
should be taken orally by the mother beginning between 14 to 34 weeks
of gestation, adminstered via IV during labor, and given to the neonate
after birth in syrup form. For adults, the following dosage regimen can be
followed:
Disease stage
Retrovir Daily Dosage (mg)
Asymptomatic ACTG 019
500
Early HIV disease (CD4 > 200 cells/cub. mm) ACTG 016
1200
Advanced HIV disease (CD4 > 200 cells/cub. mm) BW 02
1500
(CD4 < 200 cells/cub. mm) ACTG 002 BW 02
600 1500
Precautions
Retrovir may have association with causing hematologic
toxicity. This includes granulocytopenia and severe anemia,
especially in patients with advanced HIV disease. Long term use
of Retrovir may also result in symptomatic myopathy. No long term effects
have been causally proven, however.
Retrovir is
eliminated from the body primarily through renal clearance and
liver metabolism. People with severe renal or liver impairment
should take reduced dosage. It should also be note that Retrovir
is not a cure for HIV. Patients being treated with Retrovir for
HIV infection may continue to develop illnesses associated
with HIV advancement, including opportunistic infections.
Combination treatment with ganciclovir, interpheron-alpha,bone marrow
suppressives, and cytotoxic agents can increase change of hemotoxicity of
Retrovir.
Contraindications
Retrovir is contraindicated for any patients with known
allergies to any components of the drug. Warnings for other drugs
should also be consulted before beginning any combination
treatment program. Patients with bone marrow compromise have
higher rates of anemia and neutropenia, so caution should be
exercised.
Potential Adverse Effects
The most common effects are headache, anesthenia, fever, nausea, GI
pain, and skin rash. Lactic acidosis, pancreatitis, vasculitis, and
sensitization reactions are all severe effects that have been reported,
however. Adverse reactions tend to worsen as HIV disease progresses, so
patients should be monitored.