Zidovir normally known as azidothymidine which consist of pyrimidine nucleoside analogue active against HIV. Reverse transcriptase enzyme is effective for viral development. Zidovir is combination with other anti-retroviral drugs for better activity. Patients administrating Zidovir tablets treatment should have better able to attach to multiple drug treatment, hence developing the compliance.
Indication of Zidovir
Zidovudine capsules, belongs to group of a nucleoside reverse transcriptase inhibitor, are indicated for the treatment in combination with other antiretroviral agents of HIV-1 infection
Mechanism action of Zidovir
Zidovudine belongs to synthetic nucleoside analogue. Inside the cell, zidovudine is phosphorylated to its active 5'-triphosphate metabolite, zidovudine triphosphate (ZDV-TP).
The primary mode of action of ZDV-TP is inhibition of reverse transcriptase (RT) through DNA chain termination after adding of the nucleotide analogue. ZDV-TP belongs to weak prohibitor of the cellular DNA polymerases α and γand has been resulted to be fused into the DNA of cells in culture.
Fastly absorbs and high plasma level of Zidovir is 0.5 to 1.5hours;
Highly distributed in body. The fundamental of Zidovir tablets are bounding to human plasma protein with the range of <38% for zidovudine. The boundserum ratio of Zidovir is less.
Zidovudine is undergoing metabolism by glucuronide conjugation.
Route of elimination of zidovudine is urine 29%; eliminated as zidovudine metabolite 45%. The half-life period ofzidovudine is 0.5 to 3 hours.
The usual dose is 300mg Zidovudine capsules for twice daily in combination with other antiretroviral.
Pediatric patients (age of 4 weeks to < 18 years)
The dose is usually calculated dependsupon body weight(kg) and not to be exceed the usual adult dose
The patient body weight
4 to <9 = 24mg/kg/day given as 12mg/kg twice daily; 8mg/kg three times daily
>9 to >30 = 18mg/kg/day given as 9mg/kg for twice daily; 6mg/kg three times daily
≥ 30 = 600mg/day given as 300mg for twice daily; 200mg for three times daily
Prevention of maternal-fetal HIV-1 transmission
Maternal dosing: Before start of labor administrate 100mg orally 5 times /day. During labor and delivery, administered 2mg/kg IV over 1 hour followed by a continuous IV infusion of 1mg/kg/hr until clamping of umbicalcord Neonatal dosing After birth Dosing within 12 hours and continue through 6 weeks of age Oral route = 8mg/kg/day total daily dose but given as 2mg/kg for every 6 hours Intrevenous route = 6mg/kg/day total daily dose but given as 1.5mg/kg infused over 30min, every 6hrs Zidovir tablet should be administered with or without food.
The over dosage of Zidovir should be treated by undergoing hemodialysis. Hemodialysis helps to remove the content of zidovudine from the body. Provide supportive measures.
The most serious adverse effects are
Aggravation of hepatitis B, Hepatic decompensated cirrhosis in patient with HCV/HIV co infection. Aggravation of anemia due to patients who are co infected with HIV-1/HCV getting ribavirin & zidovudine. Hematological toxicity, Symptomatic myopathy, Lactic acidosis or hepatomegaly with steatosis, Pancreatitis, Immune reconstitution syndrome, Lipoatrophy
The most common side effects
Headache, Malaise, Fatigue, Anorexia, Cough, Rashes, Musculoskeletal pain, Loss of appetite, Dyspepsia, Abdominal cramps, Neuropathy, Insomnia, Myalgia, Arthralgia, Dizziness, Depression, Nasal signs
The possible adverse occurred during or after completion of therapy with Zidovir .
In case of neutropenia or thrombocytopenia, Zidovir treatment should be postponed. Periodic blood cells count should be taken.
Lactic acidosis or hepatomegaly with steatosis
This condition may leads to produce fatal cases, majorly in women. The most common adverse effect is obesity In severe condition treatment should be discontinued.
In HIV-1 infected patients who are receiving Duovir having a chance of getting myopathy. The prolonged use of zidovudine is responsible for onset of myopathy in patients.
Hepatitis B co infection
To overcome the post treatment aggravation of hepatitis infection, patient should be monitored with hepatic function frequently after completion of treatment. The concurrent use of lamivudine may leads to cause this type of infection.