Revised US adult treatment guidelines published this week recommend that first –line antiretroviral therapy should consist of a combination based on either lopinavir or efavirenz plus 3TC, with either AZT, or d4T as the third drug in the combination. Tenofovir is a first line option when partnered with efavirenz.
Unlike the draft UK guidelines issued recently by the British HIV Association, the US guidelines continue to downgrade the use of nevirapine. The guidelines discussion highlights questions over the result of the 2NN study, argued by some to show that nevirapine and efavirenz are comparable.
“In the design of the 2NN study, a difference between the two treatment groups of 10% in treatment failure at 48 weeks was prespecified to be clinically meaningful”, the document notes. “The results of the study indicate that a difference of this magnitude cannot be ruled out." (In the 2NN study, the 95% confidence intervals (the bounds within which statisticians say that, with 95% confidence, a figure lies) suggested that a difference of more than 10% in proportions with undetectable viral load at week 48 was possible, alhtough the headline result of the study suggested that the two drugs were `comparable`.)
The US guidelines also continue to recommend the use of d4T in first-line treatment, a practice discouraged by the British HV Association draft guidelines.
The use of triple nucleoside analogue regimens (i.e. Trizivir), also discouraged by the new British guidelines, continues to be an option for consideration in patients with viral load below 100,000 copies, says the US document.
Further information
The updated guidelines can be downloaded here.
The draft British HIV Association guidelines are available here.