Drug profile of Duovir
Duovir tablets are combination tablets which containing an active constituents known as lamivudine & zidovudine as an anti-retroviral medications.
This combinational therapy is used with other anti-retroviral drugs for better activity.
Duovir is pharmacologically categorized as nucleoside reverse transcriptase inhibitor. Reverse transcriptase enzyme is essential for viral production.
Duovir containing 150mg of lamivudine & 300mg of zidovudine,
Patients who are getting Duovir tablets treatment should have better able to attach to complex drug therapy regimen, thereby improving the compliance.
Brand name: Duovir
Active constituents: lamivudine & zidovudine
Strength: 150mg & 300mg respectively
Pack: 60 tablets in a container
Category: Anti-retroviral drug
Prescribing information of Duovir
The most important prescribing information of Duovir is;
Basically Duovir is a combination of two most prominent nucleoside analogues which exhibiting anti-retroviral activity.
Duovir should be combined with other anti-retroviral drugs for better avction.
Mechanism of Duovir
Duovir has two prime components like lamivudine & zidovudine
Lamivudine undergoes phosphorylation intracellularly, to form active moiety known as 5’ triphosphate metabolite, lamivudine triphosphate which exhibits anti-retro vral action.
The most important action of this metabolite is prohibition of reverse transcriptsethrough DNA chain elimination which is occurring after insertion of nucleoside analogues.
The mechanism of action of zidovudine is also similar to lamivudine, like inhibition of viral reverse transcriptase by zidovudine triphosphate which is an active moiety of zidovudine.
Finally viral DNA chain termination occurs.
The absorption of lamivudine and zidovudine is occurs very quickly.
The oral bioavailability of Duovir;
Lamivudine: 86 ± 16%; zidovudine: 64 ± 10%
The Duovir is highly distributed in body.
The component of Duovir tablets are binding to human plasma protein with the range of <36% for lamivudine; <38% for zidovudine.
The binding plasma ratio of Duovir is low.
The known metabolite of lamivudine is trans-sulfoxide metabolite.
Biotransformation is occurred by using sulfotransferases.
Zidovudine is undergoes metabolism by glucoronide conjugation.
Duovir is undergoes hepatic metabolism elimination.
The major route of elimination of lamivudine occurs via urine as an unchanged form.
It also excreted in human milk.
The terminal half life period of lamivudine is 5 to 7 hours.
Route of elimination of zidovudine is 29% through urine; 45% excreted as zidovudine metabolite.
The terminal half life period of zidovudine is 0.5 to 3 hours.
The renal creatinine clearance of lamivudine is 0.22 plus or minus 0.06 L/hr/kg; zidovudine is 0.34 plus or minus 0.05 L/hr/kg.
When to take the Duovir
Duovir tablet should be administered with or without food.
Dosage regimens of Duovir
The prescribed dose of Duovir in adult patients with the weight of greater or equal to 30kg should be recommended as;
One tablet of Duovir should be administered orally as two times a day.
The recommended prescribed dose in pediatric patients is one tablet to be taken as two times a day.
Before prescribing the Duovir tablets for pediatric patients, consult should check whether patient can able to swallow the tablets or not. In that condition, oral solution should be prescribed.
Duovir should not be suggested for the pediatric patients with weighing less than 30kg or who have low renal function. Duovir should not used in patient with CrCl less than 50ml/min.
Duovir should not be suggested for hepatic impaired patients.
Duovir caused side effects
The most serious adverse effects are;
Lactic acidosis or hepatomegaly with steatosis
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.
Immune reconstitution syndrome
The most common side effects;
Loss of appetite
Elevated AST, ALT
Increased blood glucose level
Stevens Johnson’s syndrome
Drug- drug interaction
Drugs which are opposing the activity of zidovudine;
The combination of zidovudine with some drugs produces antagonist effects, like
Nucleoside analogues like ribavirin
Duovir tablets are concurrent use with ribavirin, Ganciclovir, interferon alfa or other drugs may elevate the hematological toxicity effect of zidovudine. Avoid this concomitant treatment.
Co administration of lamivudine with sorbitol leads to produce sorbitol dose dependent depletion of lamivudine exposure; this may cause loss of effect.
Avoid this combination therapy.
Duovir should not be combined with Zalcitabine which may alters t or inhibits the intracellular phosphorylation of one another.
Food drug interaction
Minor food drug interaction may occur, this do not cause any alteration or harm during the treatment.
Anaphylactic reaction may occur in the patient are contraindicated to the component present in Duovir tablets.
Hematological toxicity, lactic acidosis or hepatomegaly with steatosis & aggravation of hepatitis B infection; these are all possible adverse occurred during or after completion of therapy with Duovir.
Periodic blood cells count should be taken.
In case of neutropenia or thrombocytopenia, Duovir treatment should be postponed.
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.
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.
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 incidence of lamivudine resistance caused hepatitis infection; the potency of lamivudine in patient with HIV-1 HCV co infection has not been evaluated.
The concurrent use of lamivudine may leads to cause this type of infection.
Ribavirin based therapy:
Duovir combined with ribavirin causes hematological problems in severe condition.
Avoid the concomitant use
Check the blood cell count during the therapy if necessary.
In Immune reconstitution syndrome, Duovir tablets should be discontinued
During Duovir treatment, there is a chance of getting depletion of subcutaneous fat.
To solve this problem, Duovir therapy should be discontinued and follow the alternative therapy for curing this adverse effect.
Pregnancy and lactation
The pregnancy category of Duovir is C
Duovir should not be used in pregnancy & lactating women
Generally HIV infected patients should not feed the baby.
Duovir metabolites are eliminated via human breast milk.
Storage and handling
Duovir tablet container should be kept at 20o to 25oC
Keep the container away from moisture, heat & light.
The missed dose of Duovir should not be taken. If missed dose should be taken without knowledge of medical adviser may causes over dosage.
In case missed dose occurs patient must be consult with physician and follow the instructions.
Correct dosing schedule should be followed for avoiding over dosage.
The over dosage of Duovir should be treated by undergoing hemodialysis.
Hemodialysis helps to remove the content of lamivudine & zidovudine from the body.
The acute over dosage condition, causes adverse effects like fatigue, headache, vomiting & hematological disturbance.
Provide supportive measures.