Indications
Tenofovir Alafenamide is a nucleoside analog reverse transcriptase inhibitor that works against the hepatitis B virus (HBV). Doctors use it to treat chronic hepatitis B virus infection in adults whose liver disease is compensated.
⚠️ Always consult a registered physician before taking any medicine.
Pharmacology
Tenofovir alafenamide is a phosphonamidate prodrug of tenofovir (a 2'-deoxyadenosine monophosphate analog). It is lipophilic and can cross cell membranes, so it enters primary hepatocytes by passive diffusion and also through the hepatic uptake transporters OATP1B1 and OATP1B3. Inside the cell, tenofovir alafenamide is hydrolysed to tenofovir, mainly by carboxylesterase 1 (CES1) in primary hepatocytes. Cellular kinases then phosphorylate the tenofovir to its pharmacologically active metabolite, tenofovir diphosphate.
Tenofovir diphosphate stops HBV replication because the HBV reverse transcriptase incorporates it into viral DNA, and this ends the DNA chain. It is a weak inhibitor of mammalian DNA polymerases, including mitochondrial DNA polymerase γ, and in cell culture there is no evidence of toxicity to mitochondria.
Pregnancy & Breastfeeding
Pregnancy: Based on prospective reports to the APR, over 660 exposures to TAF-containing regimens during pregnancy ended in live births (over 520 exposed in the first trimester and over 130 exposed in the second/third trimester). Birth defects were seen in 4.2% of live births (95% CI: 2.6% to 6.3%) after first trimester exposure and in 3.0% (95% CI: 0.8% to 7.5%) after second/third trimester exposure to TAF-containing regimens. One methodologic limitation of the APR is its use of MACDP as the external comparator group. MACDP is not disease-specific, it evaluates women and infants from a limited geographic area, and it does not include outcomes for births that occurred at less than 20 weeks gestation.
Lactation: It is not known whether Tenofovir alafenamide and its metabolites are present in human breast milk, affect human milk production or have effects on the breastfed infant. Tenofovir has been shown to be present in the milk of lactating rats and rhesus monkeys after administration of TDF. It is not known if tenofovir alafenamide can be present in animal milk. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for Tenofovir alafenamide and any potential adverse effects on the breastfed infant from Tenofovir alafenamide or from the underlying maternal condition.
⚠️ Talk to your doctor before taking any medicine during pregnancy or while breastfeeding.
Dosage Reference
⚠️ Reference ranges from official sources only. Consult your doctor for personalized dosing.
Side Effects & Interactions
Side Effects
No side-effect data recorded yet.