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The adverse events reported during intravenous administration of RETROVIR IV (zidovudine injection) Infusion are similar to those reported with oral administration; neutropenia and anemia were reported most frequently. Long-term intravenous administration beyond 2 to 4 weeks has not been studied in adults and may enhance hematologic adverse events. Local reaction, pain, and slight irritation during intravenous administration occur infrequently.
Table 5 summarizes events reported at a statistically significantly greater incidence for patients receiving RETROVIR orally in a monotherapy study:
Table 5. Percentage (%) of Patients with Adverse Events*
in Asymptomatic HIV Infection (ACTG 019)
|Adverse Event|| RETROVIR 500 mg/day
(n = 453)
(n = 428)
|Body as a whole|
| *Reported in ≥ 5% of study population.
† Not statistically significant versus placebo.
In addition to the adverse events listed in Table 5, other adverse events observed in clinical studies were abdominal cramps, abdominal pain, arthralgia, chills, dyspepsia, fatigue, hyperbilirubinemia, insomnia, musculoskeletal pain, myalgia, and neuropathy.
Selected laboratory abnormalities observed during a clinical study of monotherapy with oral RETROVIR are shown in Table 6.
Table 6. Frequencies of Selected (Grade 3/4) Laboratory Abnormalities
in Patients with Asymptomatic HIV Infection (ACTG 019)
|Adverse Event|| RETROVIR 500 mg/day
(n = 453)
(n = 428)
|Anemia (Hgb < 8 g/dL)||1.1%||0.2%|
|Granulocytopenia ( < 750 cells/mm3)||1.8%||1.6%|
|Thrombocytopenia (platelets < 50,000/mm3)||0%||0.5%|
|ALT ( > 5 x ULN)||3.1%||2.6%|
|AST ( > 5 x ULN)||0.9%||1.6%|
|Alkaline phosphatase ( > 5 x ULN)||0%||0%|
|ULN = Upper limit of normal.|
Study ACTG300: Selected clinical adverse events and physical findings with a ≥ 5% frequency during therapy with EPIVIR 4 mg/kg twice daily plus RETROVIR 160 mg/m2 orally 3 times daily compared with didanosine in therapy-naive ( ≤ 56 days of antiretroviral therapy) pediatric patients are listed in Table 7.
Table 7. Selected Clinical Adverse Events and Physical Findings
( ≥ 5% Frequency) in Pediatric Patients in Study ACTG300
|Adverse Event|| EPIVIR plus RETROVIR
(n = 236)
(n = 235)
|Body as a Whole|
|Nausea & vomiting||8%||7%|
|Abnormal breath sounds/wheezing||7%||9%|
|Ear, Nose, and Throat|
|Signs or symptoms of ears*||7%||6%|
|Nasal discharge or congestion||8%||11%|
|*Includes pain, discharge, erythema, or swelling of an ear.|
Selected laboratory abnormalities experienced by therapy-naive ( ≤ 56 days of antiretroviral therapy) pediatric patients are listed in Table 8.
Table 8. Frequencies of Selected (Grade 3/4) Laboratory Abnormalities
in Pediatric Patients in Study ACTG300
|Test (Abnormal Level)||EPIVIR plus RETROVIR||Didanosine|
|Neutropenia (ANC < 400 cells/mm3)||8%||3%|
|Anemia (Hgb < 7.0 g/dL)||4%||2%|
|Thrombocytopenia (platelets < 50,000/mm3)||1%||3%|
|ALT ( > 10 x ULN)||1%||3%|
|AST ( > 10 x ULN)||2%||4%|
|Lipase ( > 2.5 x ULN)||3%||3%|
|Total amylase ( > 2.5 x ULN)||3%||3%|
| ULN = Upper limit of normal.
ANC = Absolute neutrophil count.
Additional adverse events reported in open-label studies in pediatric patients receiving RETROVIR 180 mg/m2 every 6 hours were congestive heart failure, decreased reflexes, ECG abnormality, edema, hematuria, left ventricular dilation, macrocytosis, nervousness/irritability, and weight loss.
The clinical adverse events reported among adult recipients of RETROVIR may also occur in pediatric patients.
Use for the Prevention of Maternal-Fetal Transmission of HIV
In a randomized, double-blind, placebo-controlled trial in HIV-infected women and their neonates conducted to determine the utility of RETROVIR for the prevention of maternal-fetal HIV transmission, RETROVIR Syrup at 2 mg/kg was administered every 6 hours for 6 weeks to neonates beginning within 12 hours following birth. The most commonly reported adverse experiences were anemia (hemoglobin < 9.0 g/dL) and neutropenia ( < 1,000 cells/mm3). Anemia occurred in 22% of the neonates who received RETROVIR and in 12% of the neonates who received placebo. The mean difference in hemoglobin values was less than 1.0 g/dL for neonates receiving RETROVIR compared to neonates receiving placebo. No neonates with anemia required transfusion and all hemoglobin values spontaneously returned to normal within 6 weeks after completion of therapy with RETROVIR. Neutropenia was reported with similar frequency in the group that received RETROVIR (21%) and in the group that received placebo (27%). The long-term consequences of in utero and infant exposure to RETROVIR are unknown.
Observed During Clinical Practice
In addition to adverse events reported from clinical trials, the following events have been identified during use of RETROVIR in clinical practice. Because they are reported voluntarily from a population of unknown size, estimates of frequency cannot be made. These events have been chosen for inclusion due to either their seriousness, frequency of reporting, potential causal connection to RETROVIR, or a combination of these factors.
Eye: Macular edema.
Urogenital:Urinary frequency, urinary hesitancy.
Read the Retrovir IV (zidovudine injection) Side Effects Center for a complete guide to possible side effects
See CLINICAL PHARMACOLOGY section (Table 4) for information on zidovudine concentrations when coadministered with other drugs. For patients experiencing pronounced anemia or other severe zidovudine-associated events while receiving chronic administration of zidovudine and some of the drugs (e.g., fluconazole, valproic acid) listed in Table 4, zidovudine dose reduction may be considered.
Antiretroviral Agents: Concomitant use of zidovudine with stavudine should be avoided since an antagonistic relationship has been demonstrated in vitro.
Some nucleoside analogues affecting DNA replication, such as ribavirin, antagonize the in vitroantiviral activity of RETROVIR against HIV; concomitant use of such drugs should be avoided.
Doxorubicin: Concomitant use of zidovudine with doxorubicin should be avoided since an antagonistic relationship has been demonstrated in vitro (see CLINICAL PHARMACOLOGY for additional drug interactions).
Phenytoin: Phenytoin plasma levels have been reported to be low in some patients receiving RETROVIR, while in 1 case a high level was documented. However, in a pharmacokinetic interaction study in which 12 HIV-positive volunteers received a single 300-mg phenytoin dose alone and during steady-state zidovudine conditions (200 mg every 4 hours), no change in phenytoin kinetics was observed. Although not designed to optimally assess the effect of phenytoin on zidovudine kinetics, a 30% decrease in oral zidovudine clearance was observed with phenytoin.
Overlapping Toxicities: Coadministration of ganciclovir, interferon alfa, and other bone marrow suppressive or cytotoxic agents may increase the hematologic toxicity of zidovudine.
Read the Retrovir IV Drug Interactions Center for a complete guide to possible interactions
Last reviewed on RxList: 4/29/2009
Additional Retrovir IV Information
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