Trade name : Tenof-EM
Active ingredient : Tenofovir Disoproxil Fumarate + Emtricitabine
Strength availability : 300 mg + 200mg
Manufactured by : Hetero dugs Ltd
Package : 30 tablets in a container
Dosage Form : Tablets
Tenof-EM is a combination of three active ingredients (Emtricitabine + Tenofovir) is used alone or with other antiviral drug for the treatment of HIV infection. Tenof-EM will not cure or prevent HIV/AIDS. Tenof-EM suppresses the HIV replication of virus cell and despite the destruction of the immune system. Tenof-EM may help to delay the problems arises from AIDS/HIV diseases. The medicine allowed purchasing only with doctors prescription.
Tenof-EM with combination of antiretroviral drug or alone medicine is indicated for the treatment of HIV-1 infection in adult and children 12yrs / >12yrs.
1. Before begin the treatment using with Tenof EM, patient should be examine thoroughly for presence of HBV infection or not.
Hepatic function test & renal function test should be monitored.
2. Patients receiving Tenof EM for PrEP, screening the HIV-1 infection for once three months. Dosage recommendation; The advised dose of Tenof EM for adults & pediatric with weight of at least 35kg is one tablet should be administered as once daily by taking with food or without food. For PrEP condition; One Tenof EM tablet should be taken as once daily for both adults & pediatric with weight of at least 35kg. Dosage adjustment for renal impaired patients; CrCl ≥50ml/min, one tablet should be taken for every 24 hours CrCl 30 to 49ml/min, one Tenof EM tablet should be taken for every 48 hours CrCl <30ml/min, Tenof EM tablet should not be recommended
MECHANISM OF ACTION :
An acyclic nucleoside phosphonate di ester associate of adenosine monophosphate is Tenofovir Disoproxil Fumarate ( Tenof-EM), that hydrolysed to Tenofovir, finally cellular enzymes phosphorylated to form Tenofovir diphosphate, an restrict chain terminator. Tenofovir contains with DNA fusion of HIV via aggressive prevention of reverse transcriptase and fusion into viral DNA. Tenofovir also inhibits hepatitis B virus polymerase, resulting in blockage of viral replication. Emtricitabine ( Tenof-EM ) is a synthetic nucleoside coordinate of cytidine, which go through phosphorylation occurring inside a cell to Emtricitabine 5'-triphosphate, then take part with deoxycytidine 5'-triphosphate and is integrated into viral DNA which causes chain termination. The drug shows activity against HIV-1, HIV-2 viruses and hepatitis B virus (HBV).
Absorption: Tenofovir ( Tenof-EM ) absorbed immediately from the GI tract, bioavailability with high fat meal is approx 25% and duration of peak plasma concentration (PPC) is 1-2hr. In Emtricitabine ( Tenof-EM ) , bioavailability is 93%(capsulel) and solution 75%, PPC is 1-2 hrs.
Distribution: Tenofovir( Tenof-EM ) volume of distribution is 1.2-1.3 L/kg and plasma protein binding is <1%, In Emtricitabine ( Tenof-EM ) independent of concentration and protein binding is <4%. METABOLISM: Tenofovir Disoproxil Fumarate ( Tenof-EM , that hydrolysed to Tenofovir, finally cellular enzymes phosphorylated to form Tenofovir diphosphate, an restrict chain terminator. In Emtricitabine ( Tenof-EM ) is limited metabolism.
Elimination: Tenofovir ( Tenof-EM ) excreted through urine by active glomerular filtration and tubular secretion and half life is 18hr. Emtricitabine ( Tenof-EM eliminated highly unchanged in urine and low limit in faeces, half life is 10hr.
Prior to administration of Tenof Em, Patients should take care of these caution as follows :
Patient with hepatomegaly or other serious factors for liver disease, Renal impairment, Pregnancy. Patient Counseling: This drug may cause dizziness, if affected, do not drive or operate machinery. Monitoring Parameters: Check the renal function and serum phosphate concentrations before start of the treatment, 4 weekly during the 1st week, and then 3 monthly. Hepatic function for several months following discontinuation. Determine HIV status in all hepatitis B virus (HBV) infected patients before the treatment.
Concentration of atazanavir decreased with interaction of tenofovir unless also co-administered with ritonavir. If taken with drugs that are excreted by active tubular secretion. Increased serum concentration of both tenofovir and emtricitabine Continues use with nephrotoxic agents will leads to Tenof-EM risk increased by renal impairment While interaction with didanosine levels become high and therefore increasing risk of pancreatitis and with a high therapy. Do not use emtricitabine with lamivudine due to same resistance profile causes high risk of lactic acidosis with α-interferon.
Tenof-EM contraindicated in patient with hypersensitivity to Efavirenz. When coadministration with voriconazole, Tenof-EM is contraindicated and lactation patient is also contraindicated with Viraday
Tenof EM is contains two drugs which is used as once daily. If patients fail to take the dose, must get advice from medical practitioner and follow the instructions. Patient maintain the regular dosing schedule for avoiding the over dosage problem.
Major effects: Lactic acidosis, severe hepatomegaly with steatosis Renal effects: Nephritis, Nephrogenic, diabetes insipidus, renal failure GI events: Anorexia, abdominal distention, diarrhea, dyspepsia, flatulence Common effects: vertigo, fatigue, raised liver enzyme, athralgia,rhabdomyolysis, osteomalacia.