Atavir is an anti-viral medication which is containing atazanavir as active moiety.which is categorized as protease inhibitor.
Atazanavir is a chemically classified as azapeptide, which is containing bis-aryl substituent on hydrazine moiety exhibits anti-retroviral activity against wild type & mutant forms of HIV protease.
Atavir capsules consist of active moiety are classified as protease inhibitor, which is involved in combination with other antiretroviral drugs for the treatment of HIV-1 infections for patients age of years and older weighing atleast 15 kg
MECHANISM OF ACTION
Atazanavir specifically restrains the infection particular preparing of viral Gag and Gag-Pol polyproteins in HIV-1 contaminated cells by official to the dynamic site of HIV-1 protease, hence keeping the arrangement of develop virions. Atazanavir isn't dynamic against HIV-2.
While administrating Atazanavir with food will increase the bioavailability and reduce the pharmacokinetics variability. The atazanavir mean oral bioavailability is 60 to 68%. The very quickly absorption of atazanavir is occurs; with Tmax value is 2.5 hours.
Atazanavir is binds to plasma proteins by 86%.
In liver, Atazanavir is highly metabolized,. The biotransformation of atazanavir majorly occurs by undergoing Monooxygenation & Dioxygenation.
The atazanavir half life period of is relatively 7 hours. The elimination half life through liver impaired is 12.1 hours.
Dosage regimens of Atavir
Atazanavir should not used alone; it should be combined with ritonavir which is majorly prescribed for therapy experienced adult patients with preceding virologic failure. The higher dose of ritonavir will cause reducing the safety profile of atazanavir. Before starting the treatment with atazanavir; Patients who are going to receiving the atazanavir should be performed with renal function test periodically for both prior and during the therapy. Serum creatinine, creatinine clearance, urine analysis should be checked frequently. Hepatic function test is also performed before starting & during the treatment. In adults: The prescribed dose of Atavir is one tablet should be administered as a single dose by combining with any of the following drugs like; Tenofovir H2 receptor antagonist: The gastric regulator drug should not be exceeding a dose equal to famotidine 40mg as two times a day. Atavir tablets should be concurrently administered with & or at least 10 hours after the dose of H2 receptor antagonist. Proton pump inhibitors: The administration of proton pump inhibitor should not superior a dose equal to Omeprazole 20mg and it should be taken 12 hours before the dose of Atavir tablets.
In therapy experienced patients (adults)
The recommended dose is one tablet of Atazanavir 300mg and Ritonavir 100mg should be administered as a single dose. Combination therapy: The recommended dose in combination with both H2RA and Tenofovir DF is 400mg of atazanavir and 100mg of Ritonavir given once daily. H2 receptor antagonist: The gastric regulator drug should not be exceeding a dose equal to famotidine 20mg as two times a day. Atavir tablets should be concurrently administered with & or at least 10 hours after the dose of H2 receptor antagonist. If patient taking H2 receptor antagonist, Atavir tablets should be taken with food. If patients administered tenofovir & H2 receptor antagonist concurrently, then Atavir tablets should not be recommend. In therapy experienced patients who are getting Atavir tablets, proton pump inhibitor should not be recommended.
In treatment Naïve Adult patients
The usual dose is Atazanavir 300mg and Ritonavir 100mg given once daily. If patients unable to tolerate Ritonavir administrate single dose of Atazanavir 400mg. When in combination with Efavirenz then administrate Atazanavir 400mg and Ritonavir 100mg
In pregnant women
The recommended dose of Atavir is; In both new commenced or already treated patients: The prescribed dose is one Atavir tablet should be administered as a single dose. In case of combination of H2RA or tenofovir DF, the recommended dose is 400mg of atazanavir & 100mg of ritonavir should be recommended as a single dose. In therapy experienced pregnant patients during 2nd or 3rd trimester, atazanavir should not be suggested.
In renal impairment
In severe renal damage patients who are not tolerated to hemodialysis, no dosage adjustment should be recommended. In therapy naïve patients with final stage of renal disease, the dose of Atavir tablets should be reduced. In HIV experienced patients with final stage of renal disease, the Atavir tablets should not be recommended.
In hepatic impairment
For mild to moderate liver damaged patients, Atavir tablets should be recommended Atavir 400mg and Atavir 300mg for administration. In severe condition, Atavir tablets should not be used.
Atavir tablets should be administered with food. Atavir tablets are fixed dose combination; it should not be broke, chew or crush.
In Atavir over dosage condition patient should be; Provide with supportive measures Gastric lavage or emesis should be provided Activated charcoal is used for removing the unabsorbed dose of Atavir Dialysis is not successive, because ritonavir is highly metabolized and binds to human plasma protein in higher extent.
Atavir caused side effects
The major adverse effects of Atavir tablets are; Cardiac conduction abnormalities Rash Increased bilirubin levels Chronic kidney disease Nephrolithiasis Cholelithiasis
The common side effects
Jaundice Scleral icterus Diarrhea Rashes Depression Myalgia Increased AST, ALT Increased lipase Increased creatine kinase Neutropenia Increased triglycerides Decreased platelets
Post marketing reports
Edema Pancreatitis Liver function abnormalities Diabetes mellitus Arthralgia Alopecia Maculopapular rash Angioedema Pruritus
Cardiac conduction abnormalities
This is due to prolonged elevation of PR intervals by atazanavir. Monitor with ECG frequently for reducing the adverse effects.
Check the blood glucose level periodically Patient must be prescribed with dose adjustment insulin or oral hypoglycemic agents. Diabetes ketoacidosis should be occurred after discontinue the treatment. Immune reconstitution syndrome: Stop the Atavir therapy. Redistribution of fat occurred in the body leads to cause obesity. To overcome the problem in severe condition, discontinue the treatment.
Symptomatic elevation of bilirubin occurs by prohibits the UDP glucuronosyl transferase. Dose reduction is not possible, once the level of bilirubin is elevates stop the treatment.
Rash is the one of the most important effect occurred on skin. Atazanavir should be stopped during rashes present.
During the Atavir treatment patient should be monitored with renal function test. Nephrolithiasis & cholelithiasis: To overcome the problem, patient must be provided with additional management. Temporary postponement or discontinuation of therapy is occurring. Adverse effects may occur due to drug interactions, like; Atavir with drugs are metabolized by CYP3A or CYP3A causes increased concentration of these drugs.
Severe bleeding occurs, discontinue the protease inhibitor therapy.
Atavir with CYP3A4 inducers causes depletion of atazanavir plasma concentration and leads to reduce the therapeutic effect of atazanavir. Atavir solubility is depends on the pH values, co administration of Atavir with gastric regulators causes depletion of plasma concentration of atazanavir.
Atavir tablet combined with drugs primarily metabolized by CYP3A or UGT1A1 causes elevating the plasma concentration of these drugs, this is because atazanavir is a prohibitor of CYP3A or UGT1A1Atavir combined with Didanosine buffered tablets, causes decreasing the effect of concentration of atazanavir.
The co administration of Didanosine EC with Atavir causes decreasing effect of concentration of Didanosine. Atavir combined with anti-coagulant, or anti-depressants may leads to cause increasing the effect of concentration of these following drugs. Atavir combined with anti-convulsants except carbamazepine, causes depletion of effect of concentration of anti-convulsants except carbamazepine. Co administration of Atavir with tenofovir DF, leads to produce increasing the effect of concentration of tenofovir.
Efavirenz depleted the exposure of atazanavir during combination. Atavir capsules combined with other protease inhibitor like saquinavir and other leads to increase the effect of concentration of these drugs. Atavir with gastric regulators causes decreasing the effect of concentration of atazanavir. Avoid the concomitant use.
PREGNANCY & LACTATION
Pregnancy category: B Atazanavir should be used in limited number of pregnant women. Atavir tablets should be used with caution only after knowing the risk factor associated with the treatment. Lactation: Breast feeding should not be allowed while the patient undergoing HIV-1 infection therapy.
Atavir should be contraindicated for; Patients suffered with hypersensitivity reaction, because patients are contraindicated to the component present in the Atavir. Atavir is contraindicated to strong CYP3A inducers; it may causes loss of effectiveness of atazanavir. Some drugs are contraindicated to Atavir like; Rifampin: decreases the concentration of atazanavir Irinotecan: Atazanavir inhibits the UGT1A1, which is responsible for metabolism of Irinotecan and elevation of irinotecan Lurasidone: life threatening condition may occur Alfuzosin: hypotension
Atavir tablet container should be kept in cool & dry place.
In case of missed dose, patient must be consult with physician and follow the instructions. Maintain the regular dosing schedule. Missed dose of Atavir should be avoided.