Singapore Drugs Database

Indication

Darunavir, co-administered with ritonavir, and with other antiretroviral agents, is indicated for the treatment of human immunodeficiency virus (HIV) infection in antiretroviral treatment-experienced adult patients, such as those with HIV-1 strains resistant to more than one protease inhibitor.

Mechanism of Action

Darunavir is a HIV protease inhibitor which prevents HIV replication by binding to the enzyme's active site, thereby preventing the dimerization and the catalytic activity of the HIV-1 protease. Darunavir selectively inhibits the cleavage of HIV encoded Gag-Pol polyproteins in virus-infected cells, which prevents the formation of mature infectious virus particles. Structual analyses suggests that the close contact that darunavir has with the main chains of the protease active site amino acids (Asp-29 and Asp-30) is an important contributing factor to its potency and wide spectrum of activity against multi-protease inhibitor resistant HIV-1 variants. Darunavir can also adapt to the changing shape of a protease enzyme because of its molecular flexibility. Darunavir is known to bind to two distinct sites on the enzyme: the active site cavity and the surface of one of the flexible flaps in the protease dimer.

Pharmacokinetics

Absorption

The absolute oral bioavailability of a single 600 mg dose of darunavir alone and after co-administration with 100 mg ritonavir twice daily was 37% and 82%, respectively.

Distribution

Metabolism

Hepatic. Darunavir is extensively metabolized by CYP enzymes, primarily by CYP3A.

Elimination

Clearance

* 32.8 L/hr [Healthy volunteers receiving intravenous administration of 400 mg of darunavir] * 5.9 L/hr [Healthy volunteers receiving intravenous administrations of 400 mg of darunavir and 100 mg of ritonavir twice daily]

Active Ingredient/Synonyms

(3R,3AS,6ar)-hexahydrofuro[2,3-b]furan-3-yl N-((1S,2R)-1-benzyl-2-hydroxy-3-(N(1)-isobutylsulfanilamido)propyl)carbamate | (3R,3AS,6ar)-hexahydrofuro[2,3-b]furan-3-yl(1S,2R)-3-[[(4-aminophenyl)sulfonyl](isobutyl)amino]-1-benzyl-2-hydroxypropylcarbamate | (3R,3AS,6ar)-tetrahydro-2H-furo[2,3-b]furan-3-yl (2S,3R)-4-(4-amino-N-isobutylphenylsulfonamido)-3-hydroxy-1-phenylbutan-2-ylcarbamate | (3R,3AS,6ar)-tetrahydro-2H-furo[2,3-b]furan-3-yl (2S,3R)-4-(4-amino-N-neopentylphenylsulfonamido)-3-hydroxy-1-phenylbutan-2-ylcarbamate | [(S)-3-[(4-Amino-benzenesulfonyl)-isobutyl-amino]-2-hydroxy-1-((R)-phenylmethyl)-propyl]-carbamic acid (3R,3as,6ar)-(hexahydro-furo[2,3-b]furan-3-yl) ester | {(1S,2R)-3-[(4-amino-benzenesulfonyl)-isobutyl-amino]-1-benzyl-2-hydroxy-propyl}-carbamic acid (3R,3as,6ar)-(hexahydro-furo[2,3-b]furan-3-yl) ester | Darunavir | Darunavirum | N-((1S,2R)-3-(((4-Aminophenyl)sulfonyl)(2-methylpropyl)amino)-2-hydroxy-1-benzylpropyl)((1S,2R,5R)-4,6-dioxabicyclo(3.3.0)oct-2-yloxy)carboxamide | Darunavir |