Description of Tenvir
* Brand Name : Tenvir
* Active ingredient: Tenofovir Disoproxil Fumarate
* Manufactured by : Cipla Ltd.
* Strength : 300 mg
* Dosage Form : Tablets
* Packing : Pack of 30 Tablets
ABOUT TENVIR 300MG
Tenvir is an antiviral drug and contains Tenofovir 300mg (active ingredient), manufactured by Cipla Ltd. Tenvir require prescription should be prescribed under medical guidance. Tenvir show activity against HIV-1 reverse transcriptase.
Pharmacology of Tenvir
MECHANISM OF ACTION
When HIV attack a patient cell, then the cell will be under control of HIV virus, then the virus develop multiple copies in the cell. For this process the virus requires an enzyme. When the activity of those enzymes is decreases the reproduction of HIV slows down.
Tenvir is a antiviral classification of group of HIV drugs called nucleoside reverse transcriptase inhibitors (NRTIs). These inhibitor stops the action of an HIV enzyme known as reverse transcriptase, in which the protein (enzyme) increases the speed of a chemical reaction. NRTIs interferes HIV from replication and decrease the amount of HIV in the body by blocking reverse transcriptase.
ABSORPTION: From the GI tract, Tenvir has fast absorption, bioavailability (25%) increases with high fat meal. The duration of peak plasma concentration of Tenvir is 1-2hrs.
DISTRIBUTION: Plasma protein binding of Tenvir is >1% and it is widely spreader into body tissue especially in kidney and liver ( volume of distribution is 1.2-1.3L/kg).
METABOLISM: Tenofovir Disoproxil Fumarate is changed into Tenvir through hydrolysis and to form active Tenvir diphosphate by cellular enzyme through phosphorylation.
ELIMINATION: By active tubular secretion and glomerular Tenvir excreted through urine. Half life is 18hr.
Indication of Tenvir
Tenvir in adult and children 12yrs and >12yrs is used with the combination of other antiretroviral agent to treat HIV-1 infection.
In adult Tenvir is indicated for treatment of chronic hepatitis B and decompensated liver diseases .
Dose & Dosage's of Tenvir
* 12yrs and older:300mg
* Unable to swallow: oral powder formulation of 7.5 scoops
* 2yrs and < 12yrs : 8 mg recommended dose.
* Unable to swallow : oral powder formulation is 1 level scoop=1 g powder contains 40mg of Tenvir disoporxil.
* 17kg Tenvir dos available in different strengths 150, 200, 250 and 300mg.
* Once daily without food, taken orally.
Side Effects of Tenvir
~ Signs of allergic reaction
Hives, Dyspnea, Swelling of (face,lips,throat,tongue)
~ Severe hepatomegaly with steatosis
~ Chest pain
~ Cold sore
~ Fast heart rate
~ Lumbar pain
~ Mild nausea,stomach ache, insomnia, itching and rashes,
~ Change in body shape (fat)
Contraindication of Tenvir
Normally No contraindication but patient hypersensitivity to any of the compnents of Tenofovir
Drug Interaction of Tenvir
* Tenvir combination with Didanosine leads to suppression of CD4+ cell counts has been found in patients
* Tenvir combination with Atazanzvir cause increase in Tenvir concentration
* Interaction with HARVONI cause increase exposure in Tenvir
* Combination with drugs that lower renal function (acyclovir,valacyclovir etc) leads to kidney problem.
* Food interaction : avoid alcohol
Precaution of Tenvir
Patient with hepatomegaly or other severe factors for liver problem. Renal impairment. Pregnant women
Patient Counselling Tenvir may cause dizziness, do not drive or operate machinery.
Monitoring Parameters regulate kidney function and serum phosphate concentrations prior to therapy, 4 wkly in 1st wk, and then 3 mthly; hepatic function for several monthth following discontinuation.
Determine HIV condition in all hepatitis B virus (HBV) infected patients before treatment.
Usage & Safety profile of Tenvir Pregnancy & Lactation
Category B : Animal studies have shown an adverse effect in fetus, so sufficient and well-developed studies in pregnant women have failed give detail about arisk to the fetus in all trimester.
Storage of Tenvir
* Tenvir stored at 250C
* Store in a cool and dry place
* Keep the Tenvir drug from children resistance
* Use Tenvir drug before expiry date.