Viropil is used adults patients weighing more than 40kg who suffering from human immunodeficiency virus (HIV) infection.
Dolutegravir: The drug belongs to class of HIV-1 antiviral agent. It prevents HIV integrase while bounding to the integrase active site and stops the strand transfer step of DNA synthesis which is specific for HIV replication cycle. Strand which transfers biochemical assays using rectified HIV-1 integrase and pre-processed substrate DNA resulted in IC values of 2.7nM and 12.6nM.
Tenofovir DF: Tenofovir DF is performs a nasty to viral action by threatening the turn around transcriptase aggregate by battling with regular substrate deoxyadenosine 5' triphosphate and after addition into DNA, by viral DNA chain eliminator.
Tenofovir is used to stoppage the viral DNA synthesis which is a require for the process of chain elimination.
Lamivudine, belongs to the class of nucleoside synthetic analogue.
Lamivudine which is phosphorylated intracellularly into active 5’ triphosphate metabolite (lamivudine triphosphate 3TC-TP.
This active metabolite involves in prevention of reverse transcriptase via chain termination after infusion of nucleotide analogue
The maximum plasma concentration of Dolutegravir is 2 to 3 hrs.
Tenofovir DF : 1hr plus/minus 0.4hrs and bioavailability is 25%
Lamivudine : 1.5± 0.5mcg/ml.
Bioavailability of Lamivudine is 80-87%
Protein binding for Dolutegravir ,Tenofovir, Lamivudine is 98.9%, <0.7-7.2% and 36%.
Dolutegravir is primarily metabolized through UGT1A1 with some contribution from CYP3A
Tenofovir occurs metabolized at cytochrome P450 enzyme
where as Lamivudine is metabolized has trans sulfoxide and the biotransformation is catalyzed by sulfotrnsferases.
Dolutegravir unchanged form is excreted via feces is 53% and urine 31%, Lamivudine excreted by urine 5.2% ± 1.4% via trans-sulfoxide metabolite
Terminal half life of Dolutegravir is 14 hrs, Tenofovir DF is 17 hours and Lamivudine is 5 to 7 hours.
WHEN TO TAKE THE DRUG
Piror to start the treatment with Viropil, Patient should be monitored for presence of HBV infection or not.
kidney function & hepatic function test should be performed.
The usual dose of Viropil is one tablet of Dolutegravir 50mg, Tenofovir DF 300mg, Lamivudine 300mg should be administered as once daily.
The drug is administered on an empty stomach.
Due to reducing the neurological problems. this tablet should be take at bed time.
The viropil prescribed dose is one tablet of dolutegravir 50mg+ lamivudine 300mg + tenofovir DF 300mg administrated for once in a day.
Dosage adjustment is needed for patients with baseline creatinine clearance <50-mL/min.
while patients with mild to moderate liver impairment has no dosage adjustment is required.
Pediatric Use: use in that patients is not indicated by FDC
Geriatric use: for the elderly patients should be used with cautions.
DRUG CAUSED SIDE EFFECTS
Aggravation of HBV
Skin related problems
Hepatic decompensated cirrhosis
Immune reconstitution syndrome
Redistribution of fat
The most common side effects;
Headache, pain, fever, abdominal pain, back pain, asthenia, diarrhea, nausea, dyspepsia, vomiting, lipodystrophy, arthralgia, insomnia
Increased cholesterol, elevation of creatine kinase, increased AST & ALT, Hematuria, neutropenia, increased serum amylase
DRUG- DRUG INTERACTION
- Viropil with CYP3A inducers causes increased clearance of Viropil & leads to reduce the plasma concentration.
- Viropil with warfarin causes fluctuation in prothrombin time & INR values.
- Viropil with anti-convulsants causes reduced effect of concentration of these drugs.
- Viropil with anti-fungals, anti-depressants, or anti-infective causes reduced effect of concentration of these drugs.
- Viropil with anti-malarial, anti-mycobacterials, calcium channel blockers, or lipid lowering drugs causes decreased effect of concentration of these drugs.
- When interaction with metformin or dofetilide will cause the plasma concentration of these drugs are increased.
FOOD DRUG INTERACTION
Concomitant use of Dolutegravir with mineral or vitamin containing substances, it may cause to increase the ion content, and this alteration intercedes with absorption of Dolutegravir and depletes the effectiveness.
A minor food drug interaction occurs.
Diet should be maintained only after getting advice from the medical adviser.
Grape fruit or juice
Vitamin E, C containing foods
Hypersensitivity reaction occurs in patients
Concomitant use with Dofetilide
Severe hepatomegaly with staetosis / Lactic acidosis : While use of nucleoside analogues involves Lamivudine alone or in combination will causes harm to fetal. Use Lamivudine with caution in patients having liver disease with known factor
New-onset or worsening Renal impairment: which including cases like acute renal failure and fanconi syndrome has reported with Tenofovir DF. While using Tenofovir has no safety and efficacy data in patients. Routine monitoring of calculated creatinine clearanceand serum phosphorus should be performed.
Patients with HIV-1 and HBV Co-infection: post therapy exacerbations of hepatitis may occur In patients infected with both HIV-1 and HBV when changing of treatment Lamivudine containing HIV-1 regimen to Lamivudine containing regimens .
PREGNANCY AND LACTATION
Pregnancy category of lamivudine: C
Pregnancy category of Tenofovir and Dolutegravir : B
The drug Viropil is highly passes via placenta, no birth defects has observed at first trimester
Ths drug must be used with probably benefits justifies the probably risk.
Breast feeding should not be allowed.
STORAGE AND HANDLING
Store at temperature below 30oC
Protect the drug from heat, moisture & light
If missed occurs, while you remember take it soon otherwise leave the missed dose Maintain the regular dosing schedule
Avoid the missed dose if possible. Please consult the doctor.
Do not self medicate the Viropil tablets.
The drug overdosage has no specific antidote. If occurs with patients then they should be monitored and provide standard supportive treatment but Tenofovir higher dose removed by hemodialysis wih an extraction co efficient of approx 54%