The document discusses several classes of anti-retroviral drugs used to treat HIV, including fusion inhibitors like enfuvirtide which bind to gp41 and prevent viral fusion, CCR5 receptor inhibitors like maraviroc which block the CCR5 co-receptor used by some HIV strains, and integrase inhibitors like raltegravir and elvitegravir which are given orally and active against HIV-1 and 2 with some cross resistance between the two. Integrase inhibitors can be used as part of initial triple drug regimens or as add-on drugs in optimized regimens for treatment-resistant cases.
4. Enfurvirtide
Binds to gp41, prevents conformational change
Not active against HIV-2
No cross resistance with other classes of ARV
Administered s/c twice daily
Given as add on drug to an optimised regimen in resistant cases
Injections are painful and cause local irritation and nodules/cysts
6. Maraviroc
Blocks CCR5 co-receptor
No effect on CXCR4 receptor tropic strains
Also used as an add on drug
Orally administered
No cross resistance with any other ARV drug
Increased risk of infection/malignancy
Metabolised by CYP450
10. Raltegravir
Given orally
Active against both HIV-1 and 2
No cross resistance to other classes of ARV but cross resistance with
elvitegravir is present
Given as add on drug in an optimised regimen
Can also be given as a component of initial triple drug regimen( 2NRTI +
1NNRTI/Integrase inhibitor) in untreated patients
Generally well tolerated
Serious adverse effects Muscle pain and rhabdomyolysis
