Country: South Africa
Language: English
Source: South African Health Products Regulatory Authority (SAHPRA)
Aspen-p
ASPEN EFAVIRENZ 600 mg (tablets) SCHEDULING STATUS: S4 PROPRIETARY NAME (and dosage form): ASPEN EFAVIRENZ 600 mg (tablets) COMPOSITION: ASPEN EFAVIRENZ 600 mg: Each tablet contains 600 mg Efavirenz . PHARMACOLOGICAL CLASSIFICATION: A.20.2.8 Antiviral agents. PHARMACOLOGICAL ACTION: Mechanism of action: Efavirenz is a selective non-nucleoside reverse transcriptase inhibitor (NNRTI) of human immunodeficiency virus type 1 HIV-1. Efavirenz diffuses into the cell where it binds adjacent to the active site of reverse transcriptase. This produces a conformational change in the enzyme and inhibits its function. Efavirenz is a noncompetitive inhibitor of HIV-1 reverse transcriptase (RT) with respect to template, primer or nucleoside triphosphates, with a small component of competitive inhibition. HIV-2 RT and human cellular DNA polymerases alpha, beta, gamma and delta are not inhibited by concentrations of efavirenz. Pharmacodynamics: In vitro HIV susceptibility: The clinical significance of in vitro susceptibility of HIV-1 to efavirenz has not been established. The in vitro antiviral activity of efavirenz was assessed in lymphoblastoid cell lines, peripheral blood mononuclear cells (PBMCs) and macrophage/monocyte cultures enriched from PBMCs. The 90 to 95% inhibitor concentration (IC90-95) of efavirenz for wild type laboratory adapted strains and clinical isolates ranged from 1,7 to 25 nM. Efavirenz demonstrated synergistic activity in cell culture in combination with the nucleoside analogue reverse transcriptase inhibitors (NRTIs), zidovudine (ZDV) or didanosine (ddi), or the protease inhibitor, indinavir (IDV). Resistance: HIV-1 isolates with reduced susceptibility to efavirenz (greater than 380- fold increase in IC90) compared to baseline can emerge in vitro. Phenotypic changes in evaluable HIV-1 i Read the complete document