Tenofovir Disoproxil Fumarate

For the treatment of HIV infection in adults and children 2 years of age and older who weigh at least 22 lb (10 kg)

Antiviral

Mechanism of Action: Tenofovir inhibits the activity of HIV reverse transcriptase by competing with the natural substrate deoxyadenosine 5-triphosphate. Specifically, the drugs are analogues of the naturally occurring deoxynucleotides needed to synthesize the viral DNA and they compete with the natural deoxynucleotides for incorporation into the growing viral DNA chain. Pharmacokinetics: Tenofovir is a water soluble diester prodrug of the active ingredient Tenofovir. The oral bioavailability of Tenofovir is approximately 25%. Following oral administration of a single dose of Tenofovir 245 mg to HIV-1 infected subjects in the fasted state, maximum serum concentrations (Cmax) are achieved in 1.0 10.4 hrs. Cmax and AUC values are 0.30 0.09 ug/mL and 2.29 + 0.69 ug hr/mL, respectively. Protein binding Very low. <0.7% to human plasma proteins and <7.2% to serum proteins. Half life Approximately 17 hours. Tenofovir is eliminated by a combination of glomerular filtration and active tubular secretion. Mechanism of Action: Tenofovir inhibits the activity of HIV reverse transcriptase by competing with the natural substrate deoxyadenosine 5-triphosphate. Specifically, the drugs are analogues of the naturally occurring deoxynucleotides needed to synthesize the viral DNA and they compete with the natural deoxynucleotides for incorporation into the growing viral DNA chain. Pharmacokinetics: Tenofovir is a water soluble diester prodrug of the active ingredient Tenofovir. The oral bioavailability of Tenofovir is approximately 25%. Following oral administration of a single dose of Tenofovir 245 mg to HIV-1 infected subjects in the fasted state, maximum serum concentrations (Cmax) are achieved in 1.0 10.4 hrs. Cmax and AUC values are 0.30 0.09 ug/mL and 2.29 + 0.69 ug hr/mL, respectively. Protein binding Very low. <0.7% to human plasma proteins and <7.2% to serum proteins. Half life Approximately 17 hours. Tenofovir is eliminated by a combination of glomerular filtration and active tubular secretion.

Tablets should be swallowed whole and can be taken with or without food. People who are unable to swallow the tablets whole may take the oral powder. Use the provided dosing scoop to measure the oral powder. Mix the oral powder with soft foods that can be swallowed without chewing, such as applesauce, baby food, or yogurt. Take the dose of oral powder right after mixing it. Do not mix the oral powder with liquid

Didanosine: Coadministration of Tafovir and didanosine should be undertaken with caution and patients receiving Tafovir should be monitored dosely for didanosine-associated adverse reactions. Atazanavir: Patients receiving atazanavir and Tafovir should be monitored for Tafovir associated adverse reactions. Lopinavir, Ritonavir: Patients receiving lopinavir/ ritonavir and Tafovir should be monitored for Tafovir-associated adverse reactions.

osteomalacia or softening of bones low amount of phosphate in the blood increased blood acidity due to high levels of lactic acid Fanconi syndrome a condition of the kidneys resulting in excessive urination thirst and vomiting acute kidney failure decreased calcification or density of bone broken bone due to disease or illness chronic kidney disease stage 3A (moderate) chronic kidney disease stage 3B (moderate) chronic kidney disease stage 4 (severe) chronic kidney disease stage 5 (failure) kidney disease with likely reduction in kidney function Allergies: Adenosine Analogues

Can cause serious, life-threatening side effects. These include a buildup of lactic acid in the blood (lactic acidosis), severe liver problems, and new or worsening kidney problems, including kidney failure

Pregnancy category B. No adequate and well-controlled studies in pregnant women. Tenofovir should be used during pregnancy only if clearly needed. The centers for disease control and prevention recommend that HIV-1-infected mothers not breastfeed their infants to avoid risking postnatal transmission of HIV-1. Pediatric Use: For the treatment of HIV-1 in pediatric patients 12 years of age and older with body weight greater than or equal to 35 kg: The dose is 245 mg Tenofovir tablet is once daily taken orally Geriatric Use: Clinical trials of Tenofovir did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. In general, dose selection for the elderly patient should be cautious, keeping in mind the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.

Limited clinical experience at doses higher than the therapeutic dose of VIREAD 300 mg is available. In Study 901, 600 mg tenofovir disoproxil fumarate was administered to 8 subjects orally for 28 days. No severe adverse reactions were reported. The effects of higher doses are not known. If overdose occurs the patient must be monitored for evidence of toxicity, and standard supportive treatment applied as necessary. Tenofovir is efficiently removed by hemodialysis with an extraction coefficient of approximately 54%. Following a single 300 mg dose of VIREAD, a four-hour hemodialysis session removed approximately 10% of the administered tenofovir dose.

Do not store above 25°C. Store in a cool and dry place, protected from light. Keep out of children’s reach.