Truvada
From Wikipharm
Intorduction: Truvada is a combination tablet of of antiretroviral agents, trenofovir and emtricitabine, which were previously separate products. However, as of July 2012, it has been approved by the Food & Drug Administration (FDA) as a post-exposure preventative for high risk groups associated with contracting AIDs.
Mechanism: HIV is caused by destruction of the immune cells using reverse transciptase. Both antiretroviral agents are nucleoside reverse transcriptase inhibitors. They are disigned to bind to the end of a newly synthesising double helix chain of the RNA virus, preventing further elongation. In combination, both drugs have been found to have a superior effect then either drug alone. However, as this drug is newly synthesised, and was designed by bioactivity screening, the exact mechanism is currently unknown.
Effectiveness/Viability: Truvada is no better then the individual componants. However, its convenience and pharmokinetic desgin prevents dosage inbalances, increases complience and reduces the pill burden. Furthermore, the drug is expensive ($13,000 yearly), requiring government subsidy. The drug is tragetted at discordant couples and gay males and must be used in conjuction with other preventative methods.
Side-effects: Thoses already suffering from HIV can experience lactic acidosis and renal impairment. However, using Truvada as a preventative may produce mild side-effects, like stomach pain, decreased weight, headache, etc
Furthermore, it has been found that the drug can be harmful if continually taken after infection and possible resistant strains may emerge due to wide-spread usage.
References:
Delahunty, T, Bushman, L, Robbins, B & Fletcher, CV 2009, 'The simultaneous assay of tenofovir and emtricitabine in plasma using LC/MS/MS and isotopically labeled internal standards', Journal of Chromatography B, vol. 877, no. 20–21, pp. 1907-14.
Drugs.com 2012, Truvada, Gilead Science Inc., retrieved 5/10 2012, <http://www.drugs.com/pro/truvada.html>.
Kasozi, E 2012, Experts approve pill to prevent Aids virus, In2EastAfrica, retrieved 5/10/12 2012, <http://in2eastafrica.net/experts-approve-pill-to-prevent-aids-virus/>.
Weston, MD 2007, 'Tenofovir', in SJE Editors-in-Chief: & BB David (eds), xPharm: The Comprehensive Pharmacology Reference, Elsevier, New York, pp. 1-3.
