Antiviral Prodrug: Tenofovir Disoproxil Fumarate (TDF) 300 mg is a tablet containing a bioavailable prodrug of tenofovir, a powerful nucleotide reverse transcriptase inhibitor.1
Dual Action: It is a highly effective antiviral agent with activity against both the Human Immunodeficiency Virus (HIV) and the Hepatitis B virus (HBV).2
Once-Daily Dosing: The 300 mg strength is a standard oral dose for adults, designed for once-daily administration, which simplifies treatment and improves adherence.3
Prodrug Conversion: After oral administration, TDF is rapidly absorbed and converted into its active form, tenofovir, which then acts on the target viruses.4
Advantages
High Efficacy: TDF is a highly effective drug for suppressing viral replication in both HIV and chronic HBV, leading to a significant reduction in viral load.5
Dual Indication: It offers the unique advantage of treating both HIV and chronic HBV, making it a crucial component of therapy for co-infected patients.6
Good Tolerability: It is generally well-tolerated, and has been associated with more favorable lipid profiles than some older antiretroviral drugs.7
Prevents Disease Progression: By controlling viral replication, it helps to prevent the progression of liver disease in HBV patients and the development of AIDS-related illnesses in HIV patients.
Uses
HIV-1 Infection: Indicated for the treatment of HIV-1 infection, always in combination with other antiretroviral agents, in adults and pediatric patients.
Chronic Hepatitis B (HBV) Infection: It is licensed for the treatment of chronic HBV in adults and pediatric patients with evidence of active viral replication and liver inflammation.
Pre-Exposure Prophylaxis (PrEP): TDF, in a fixed-dose combination with emtricitabine, is also used for PrEP to reduce the risk of sexually acquired HIV-1 infection in at-risk individuals.8
Post-Exposure Prophylaxis (PEP): It is a key component of PEP regimens to prevent HIV infection after a potential exposure, such as a needlestick injury.9
Nature
Nucleotide Reverse Transcriptase Inhibitor (NtRTI): TDF belongs to the NtRTI class of drugs, which are synthetic analogs of adenine 5′-monophosphate.10
Mechanism of Action: After being converted to its active metabolite, tenofovir diphosphate, it competitively inhibits the viral enzyme reverse transcriptase in HIV and DNA polymerase in HBV.11
DNA Chain Termination: By incorporating into the viral DNA chain, tenofovir acts as a chain terminator, effectively stopping the DNA from being built and preventing the virus from replicating.12
Renal Excretion: TDF is primarily eliminated by the kidneys.13 Therefore, it is important to monitor renal function before and during treatment, and dose adjustments may be necessary for patients with kidney impairment.
Storage
Temperature: Store TDF tablets at controlled room temperature, typically between 1420∘C to 1525∘C (1668∘F to 1777∘F).18
Protection: Keep the tablets in their original, tightly closed container, protected from light and moisture.
Administration: The tablets can be taken with or without food. However, taking it with food can increase its bioavailability.
Patient Warning: Patients with HBV should be educated that abruptly stopping the medication can lead to a severe flare-up of their hepatitis, so they should not discontinue it without consulting their doctor.
