DAPIRING

Indications

• HIV pre-exposure prophylaxis
• HIV prevention in women

Dosage

Adults: The dosing for dapivirine is typically one vaginal ring inserted and left in place for 28 days. After 28 days, the ring should be replaced with a new one.

Mechanism of action

Dapivirine inhibits the reverse transcriptase enzyme of the HIV virus, which is essential for converting viral RNA into DNA. This action effectively prevents the replication of the virus within host cells, thereby reducing viral load and transmission risk.

Pharmacodynamics

Dapivirine exhibits dose-dependent inhibition of HIV-1 replication. Its mechanism of action is characterized by binding to the reverse transcriptase enzyme, which disrupts the viral lifecycle. The localized delivery through the vaginal ring ensures higher concentrations at the site of potential infection, enhancing its prophylactic efficacy.

Pharmacokinetics

Dapivirine is absorbed locally from the vaginal ring, achieving therapeutic concentrations in vaginal tissue. It undergoes metabolism primarily in the liver, with a half-life that supports once-monthly dosing. The drug is eliminated through both renal and fecal pathways, and its pharmacokinetic profile allows for sustained release and efficacy over time.

Pregnancy

Dapivirine should not be used during pregnancy unless the potential benefit justifies the potential risk to the fetus. It is classified as a pregnancy category C drug.

Breast-feeding

It is not known whether dapivirine is excreted in human milk. Caution should be exercised when prescribing to nursing mothers.

Storage

Store at room temperature, away from moisture and heat. Keep out of reach of children.

Formulations

• {'formulation': 'Dapivirine vaginal ring', 'strength': '25 mg'}