Retrovir

Retrovir contains the active element zidovudine.

This component, penetrating into the cell, participates in metabolic processes with the help of the kinases available in it, being converted into 5-triphosphate (TF). Zidovudine-TF is a substance that competitively slows down the reverse viral HIV transcriptase. The antiviral effect of the drug develops according to the principle of its passage in the form of monophosphate into the DNA of the viral chain and the subsequent slowdown of the replication processes. [1]

Indications Retrovir

It is used in the course of antiretroviral treatment in people with HIV infection . In addition, it can be prescribed to women with HIV + status during pregnancy over 14 weeks.

Release form

The release of the medicinal substance is made in capsules - 100 pieces inside the bottle; in a pack - 1 such bottle. In addition, capsules can be packed in cell plates - 10 pieces each; there are 10 such records inside the box.

Pharmacokinetics

Zidovudine has good absorption inside the gastrointestinal tract; the level of bioavailability is within 60-70%. Indicators of intraplasma Cmax after taking the drug inside in a portion of 5 mg / kg at 4-hour intervals are 7.1 micro.

After intravenous injection of the drug, the half-life is 1.1 hours, and the average value of the total clearance is 27.1 ml / minute / kg; the indicators of the distribution volume are equal to 1.61 / kg. The level of clearance of zidovudine is significantly higher than the CC index, which demonstrates the significant role of tubular secretion in excretion processes. [2]

Zidovudine is able to cross the placenta and is registered inside the fetal blood with amniotic fluid. Protein synthesis is rather weak - within 34-38%. [3]

Dosing and administration

Therapy using Retrovir is possible only under the supervision of a doctor who has experience in treating people with HIV + status.

For an adult and a child weighing more than 30 kg, the administration of 0.5-0.6 g of the substance is prescribed (the dosage is divided into 2 administrations).

A child, whose weight is in the range of 21-30 kg, needs to use 0.2 g of drugs 2 times a day, along with other antiretroviral substances.

Individuals weighing 14-21 kg are prescribed 0.1 g of medication (1 capsule in the morning) and 0.2 g (2 capsules in the evening).

For a child weighing 8-14 kg, a dosage of 0.1 g is required (1 capsule 2 times a day).

An infant weighing less than 8 kg, as well as those who cannot swallow a capsule, should use the medication in the form of a solution for oral administration.

Use Retrovir during pregnancy

Zidovudine is able to cross the blood-placental barrier, which is why the drug can be used during pregnancy only for a period of more than 14 weeks. It is allowed to enter it earlier only if there are vital indications.

Contraindications

Among the contraindications:

• administration to persons diagnosed with zidovudine intolerance;
• use in people with an abnormally low neutrophil count (less than 0.75x10 9 / l) or a pathologically reduced hemoglobin value (less than 7.5 g / l);
• appointment with GV.

Side effects Retrovir

With the introduction of Retrovir, the development of disorders of the function of the bloodstream organs is possible - among such leuko-, neutro-, thrombocyto- or pancytopenia, lactic acidosis and anemia of the aplastic type.

In addition, patients may experience the following side signs:

• depression, seizures, headaches, severe anxiety, mental impairment, sleep disorders and paresthesia;
• cardiomyopathy;
• dyspnea or cough;
• dyspeptic disorders, bloating, taste changes and pancreatitis;
• allergy symptoms and hives.

Overdose

The introduction of drugs in increased portions leads to the potentiation of side effects.

To stabilize the patient's condition, it is necessary to perform gastric lavage and carry out symptomatic measures.

Interactions with other drugs

Lamivudine leads to a moderate increase in the Cmax of zidovudine (28%), while not affecting the AUC. The pharmacokinetic parameters of lamivudine are not altered by zidovudine.

Probenecid attenuates glucuronidation and increases the AUC in terms of the half-life of zidovudine. The use of probenecid leads to a decrease in intrarenal excretion of glucuronide with zidovudine.

Because ribavirin is a zidovudine antagonist, these drugs are not used in combination.

Administration together with rifampicin causes a decrease in the AUC value of zidovudine by about 48 ± 34% (there is no information on the clinical significance of such a change).

Zidovudine inhibits the processes of phosphorylation of stavudine inside cells.

The drug reduces the blood level of phenytoin (in the case of their combination, the plasma parameters of the latter should be monitored).

Aspirin, lorazepam, codeine with paracetamol, naproxen and morphine, as well as cimetidine, isoprinosine with indomethacin, oxazepam and ketoprofen with dapsone and clofibrate are able to interfere with the metabolic processes of zidovudine (they competitively slow down glucuronization or inhibit micro-liver metabolism). Therefore, you need to be careful when using such combinations.

The simultaneous administration of Retrovir and nephrotoxic or myelotoxic substances (especially in the provision of emergency ambulances), including flucytosine, vincristine and pentamidine with ganciclovir, and in addition, amotericin, doxorubicin and dapsone with vinblastine, interferon, co-trimoxazole, and pyrimetaminazole and pyrimetaminazole and pyrimetaminazole side symptoms of the first (it is required to monitor the work of the kidneys and blood parameters, and also reduce the dosage, if necessary).

Radiation therapy potentiates the myelosuppressive activity of zidovudine.

Storage conditions

Retrovir must be kept out of the reach of small children, light and moisture. Temperature values - no more than 30 ° С.

Shelf life

Retrovir is allowed to be used for a 5-year term from the date of manufacture of the pharmaceutical product.

Analogs

The analogs of the drug are the substances Lazid, Zidolam and Virokomb with Lamihop Z, and in addition, Duovir, Lamivudin, Zovilam and Kombivudin. The list also includes Zidovir, Trizivir, Combivir with Zidovudine, Nardin and Lazivudine.