Tenvira

• HIV infection

This is indicated for the treatment of: Chronic hepatitis B virus infection in adults HIV infected adults in combination with other anti retroviral agents

N/A

Tenofovir is contraindicated in patients with known hypersensitivity to Tenofovir or any component of the product.

Tenofovir Disoproxil Fumarate, an acyclic nucleotide analogue of adenosine monophosphate, is a pro-drug of Tenofovir. It shows activity against hepatitis B virus polymerase and HIV reverse transcriptase after phosphorylation to the active diphosphate form. Tenofovir diphosphate inhibits viral polymerase (reverse transcriptase) by directly competing with the natural substrate deoxyribonucleotide and by causing DNA chain termination after its incorporation into viral DNA.

Co-administration of Tenofovir with anti-retroviral, entecavir, lamivudine, methadone, oral contraceptives, ribavirin and tacrolimus did not result in significant drug interactions. The effects of co-administration of Tenofovir with other drugs that are renally eliminated or are known to affect renal function have not been evaluated.

The most common side effects are nausea, vomiting, diarrhea and flatulence.

There is no experience of Tenofovir overdose reported in patients

Pregnancy: Pregnancy category B. It should be used during pregnancy only if clearly needed.Lactation: It is not known whether it is excreted in human milk. Mothers should be instructed not to breast feed if they are taking Tenofovir.

Co-administration with other drugs: Tenofovir should not be administered concurrently with Emtricitabine & Tenofovir combination or Adefovir Dipivoxil.Lactic Acidosis & Severe Hepatomegaly with Steatosis: Though the risk of occurrence of lactic acidosis is low for Tenofovir, treatment should be suspended in any patient who develops lactic acidosis or hepatotoxicity. Exacerbation of hepatitis after discontinuation of treatment: Discontinuation of Tenofovirtherapy may be associated with severe acute exacerbation of hepatitis.

Pediatric use: Safety and effectiveness of Tenofovir in pediatric patients below the age of 18 years have not been established.Geriatrics use: Clinical studies of Tenofovir did not include sufficient numbers of subjects aged 65 years and over to determine whether they respond differently from younger subjects. But care should be taken in dose selection, and it may be useful to monitor renal function.Renal Impairment: Haemodialysis patients: 300 mg once every 7 days or after a cumulative total of 12 hr of dialysis. CrCl (10-29 mL/min): 300 mg 72-96 hrly. CrCl (30-49 mL/min): 300 mg 48 hrly. Hepatic impairment: No dose adjustment is required in patients with hepatic impairment.