Retrovir AZT Uses, Dosage, Side Effects and more

Retrovir AZT is converted intracellularly to zidovudine triphosphate, which inhibits replication of retroviruses, including HIV, by interfering with viral RNA-directed DNA polymerase (reverse transcriptase).

Retrovir AZT is a nucleoside reverse transcriptase inhibitor (NRTI) with activity against Human Immunodeficiency Virus Type 1 (HIV-1). Retrovir AZT is phosphorylated to active metabolites that compete for incorporation into viral DNA. They inhibit the HIV reverse transcriptase enzyme competitively and act as a chain terminator of DNA synthesis. The lack of a 3'-OH group in the incorporated nucleoside analogue prevents the formation of the 5' to 3' phosphodiester linkage essential for DNA chain elongation, and therefore, the viral DNA growth is terminated.

Trade Name Retrovir AZT
Availability Prescription only
Generic Zidovudine
Zidovudine Other Names Azidothymidine, Zidovudina, Zidovudine, Zidovudinum
Related Drugs Biktarvy, Truvada, tenofovir, ritonavir, abacavir, emtricitabine, lamivudine, Complera, Atripla, Stribild
Type
Formula C10H13N5O4
Weight Average: 267.2413
Monoisotopic: 267.096753929
Protein binding

30-38%

Groups Approved
Therapeutic Class Drugs for HIV / Anti-retroviral drugs
Manufacturer
Available Country Switzerland
Last Updated: January 7, 2025 at 1:49 am

Uses

Retrovir AZT, a nucleoside reverse transcriptase inhibitor, is used for combination with other antiretroviral agents for the treatment of HIV-1 infection.Prevention Of Maternal-Fetal HIV-1 Transmission Retrovir AZT is used for the prevention of maternal-fetal HIV-1 transmission. The indication is based on a dosing regimen that included 3 components:

Points to consider prior to initiatingRetrovir AZT in pregnant women for the prevention of maternal-fetal HIV-1 transmission include:

Retrovir AZT is also used to associated treatment for these conditions: HIV Transmission, Human Immunodeficiency Virus (HIV) Infections, Perinatal HIV transmission

How Retrovir AZT works

Retrovir AZT, a structural analog of thymidine, is a prodrug that must be phosphorylated to its active 5′-triphosphate metabolite, zidovudine triphosphate (ZDV-TP). It inhibits the activity of HIV-1 reverse transcriptase (RT) via DNA chain termination after incorporation of the nucleotide analogue. It competes with the natural substrate dGTP and incorporates itself into viral DNA. It is also a weak inhibitor of cellular DNA polymerase α and γ.

Dosage

Retrovir AZT dosage

Prophylaxis of HIV infection in neonates:

HIV infection:

Prophylaxis of maternal-fetal HIV transmission:

May be taken with or without food.

Side Effects

Dizziness, headache, malaise, myalgia, GI symptoms (e.g. abdominal pain, diarrhoea, nausea, vomiting), anorexia, immune reconstitution syndrome, lipodystrophy, metabolic abnormalities, mitochondrial dysfunction, osteonecrosis; raised liver enzymes, creatine phosphokinase; hyperbilirubinaemia, myalgia, myositis. Rarely, aplastic anaemia, pure red cell aplasia, pancytopenia, thrombocytopenia, rhabdomyolysis, cardiomyopathy, convulsions, pancreatitis.

Toxicity

Symptoms of overdose include fatigue, headache, nausea, and vomiting. LD50 is 3084 mg/kg (orally in mice).

Precaution

Severe renal and hepatic impairment. Childn. Pregnancy.

Interaction

Decreased plasma concentration with rifampicin resulting in partial or total loss of efficacy of zidovudine. Increased risk of anaemia with ribavirin in patients co-infected with HCV. Antagonistic effect with stavudine or doxorubicn. Increased plasma level with probenecid, atovaquone, valproic acid, fluconazole, or methadone. May alter phenytoin blood levels. Increased adverse effect with potentially nephrotoxic or myelosuppressive drugs (e.g. systemic pentamidine, dapsone, pyrimethamine, co-trimoxazole, amphotericin, flucytosine, ganciclovir, interferon, vincristine, vinblastine, doxorubicin). Reduced absorption with clarithromycin.

Food Interaction

[Minor] Food may have variable effects on the oral bioavailability of zidovudine.

Fatty foods have been reported to decrease the rate and extent of zidovudine absorption following oral administration.

In a study of 13 AIDS patients, mean peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) of zidovudine were 2.8 and 1.4 times higher, respectively, in fasting patients than in those administered the medication with breakfast.

In addition, variations in plasma zidovudine concentrations were increased when administered in the fed state.

In another study of eight patients, the time to reach peak concentration (Tmax) was increased from 0.68 to 1.95 hours, and Cmax was reduced by 50% when zidovudine was administered with a liquid high-fat meal relative to fasting.

Protein meals can also delay the absorption and reduce the Cmax of zidovudine, although the extent of absorption is not significantly affected.

The clinical significance of these alterations, if any, is unknown.

The product labeling states that zidovudine may be taken with or without food.

Retrovir AZT Drug Interaction

Moderate: rosuvastatin, valproic acidMinor: sulfamethoxazole / trimethoprim, sulfamethoxazole / trimethoprim, lopinavir / ritonavir, ritonavir, acetaminophen, phenytoinUnknown: ciprofloxacin, ubiquinone, lamivudine / zidovudine, copper gluconate, lamivudine, epoetin alfa, glycerin, raltegravir, darunavir, emtricitabine / tenofovir, cyanocobalamin, cholecalciferol

Retrovir AZT Disease Interaction

Major: bone marrow suppression, myopathy, hepatotoxicity, renal dysfunction

Volume of Distribution

Apparent volume of distribution, HIV-infected patients, IV administration = 1.6 ± 0.6 L/kg

Elimination Route

Rapid and nearly complete absorption from the gastrointestinal tract following oral administration; however, because of first-pass metabolism, systemic bioavailability of zidovudine capsules and solution is approximately 65% (range, 52 to 75%). Bioavailability in neonates up to 14 days of age is approximately 89%, and it decreases to approximately 61% and 65% in neonates over 14 days of age and children 3 months to 12 years, respectively. Administration with a high-fat meal may decrease the rate and extent of absorption.

Half Life

Elimination half life, HIV-infected patients, IV administration = 1.1 hours (range of 0.5 - 2.9 hours)

Clearance

Elimination Route

As in adult patients, the major route of elimination was by metabolism to GZDV. After intravenous dosing, about 29% of the dose was excreted in the urine unchanged and about 45% of the dose was excreted as GZDV.

Pregnancy & Breastfeeding use

Pregnancy Category C. Either studies in animals have revealed adverse effects on the foetus (teratogenic or embryocidal or other) and there are no controlled studies in women or studies in women and animals are not available. Drugs should be given only if the potential benefit justifies the potential risk to the foetus.

Contraindication

Hypersensitivity; abnormally low neutrophil counts (<0.75 x 109/L) or Hb levels (<7.5 g/dL or 4.65 mmol/L); newborn infants with hyperbilirubinaemia requiring treatment other than phototherapy, or with increased transaminase levels >5 times the ULN. Lactation. Concomitant use with interferon alfa (with or witho ribavirin) in HIV and hepatitis B or C virus co-infected patients.

Special Warning

Renal Impairment:

Hepatic Impairment: Dose reduction may be needed.

Acute Overdose

Symptoms: Vomiting, CNS effects (e.g. fatigue, dizziness, drowsiness, lethargy, confusion), haematologic effects (e.g. anaemia, decreased Hb). Bone marrow hypoplasia, mild ataxia, tonic-clonic seizure and increased serum concentration of AST and ALT may also occur. Management: Supportive and symptomatic treatment. Induce emesis and admin activated charcoal to prevent further absorption of unrecovered drug.

Interaction with other Medicine

Store between 15-25° C.

Innovators Monograph

Retrovir AZT contains Zidovudine see full prescribing information from innovator Retrovir AZT Monograph, Retrovir AZT MSDS, Retrovir AZT FDA label

FAQ

What is Retrovir AZT used for?

Retrovir AZT is used along with other medications to treat human immunodeficiency virus (HIV) infection.

How is Retrovir AZT administered?

Retrovir AZT injection Infusion is administered intravenously at a constant rate over 1 hour.

What is the side effect of Retrovir AZT?

Headache, nausea, vomiting, trouble sleeping, or loss of appetite may occur. If any of these effects persist or worsen, notify your doctor or pharmacist promptly. Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects.

Is Retrovir AZT still used?

Retrovir AZT is still used in combination with other ARVs for the treatment of HIV.

Is Retrovir AZT safe in pregnancy?

Retrovir AZT was well tolerated by mothers and infants; there was no difference in pregnancy-related side effects between the treatment groups.

Is Retrovir AZT safe during breastfeeding?

Retrovir AZT has been well studied during breastfeeding. Milk levels are low and most breastfed infants do not have detectable blood levels. Some breastfed infants have developed anemia during maternal therapy.

How do I know if Retrovir AZT is working?

You will need to have regular blood tests to check how well your medicines are working. It is important that you continue to take Retrovir AZT and your other antiretroviral treatment regularly.

Who should not take Retrovir AZT?

You should not use Retrovir AZT if you are allergic to it.You may develop lactic acidosis, a dangerous build-up of lactic acid in your blood. This may be more likely if you have other medical conditions, if you've taken HIV medication for a long time, or if you are a woman. Ask your doctor about your risk.

Is Retrovir AZT an antibiotic?

Retrovir AZT also has antibacterial properties, though not routinely used in clinical settings.

How can I use Retrovir AZT?

Retrovir AZT usually taken twice a day by adults and two to three times a day by infants and children. Infants 6 weeks of age and younger may take Retrovir AZT every 6 hours.

Can I drink alcohol with Retrovir AZT?

Avoid drinking alcohol.Retrovir AZT may increase your risk of liver damage or lactic acidosis.

Can I take Retrovir AZT for a long time?

Long-term use of Retrovir AZT can cause muscle weakness, or loss of muscle tissue similar to "wasting syndrome" caused by HIV.

How does Retrovir AZT work?

Retrovir AZT works by inhibiting the enzyme reverse transcriptase that HIV uses to make DNA and therefore decreases replication of the virus.

*** Taking medicines without doctor's advice can cause long-term problems.
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