The publication of a study in the New England Journal of Medicine has led to a war of words for and against the use of structured treatment interruptions (STIs) for HIV+ patients. Advocates have suggested that STIs give patients a break from the side effects of drugs and allow the virus to mutate back to a form that is more susceptible to therapy. Drug resistance is one of the main challenges to therapy. The new study, which is the largest so far to test this theory, indicates that in some patients, the 'drug holiday' could actually be detrimental, causing more frequent progression of disease and speeding up the attack on the immune system.

Jody Lawrence of the University of California, who led the study, claims that the results were “disappointing” and that STI “did not work and should be avoided” by drug-resistant HIV+ patients (BBC News Online; HealthDay). This claim was supported by Bernard Hirschel of Cantonal University Hospital, Geneva, who said, “it is hard to see what could be achieved by interrupting treatment for a few weeks” (Reuters).

However, Anthony Fauci (NIAID Director) warned against over-generalizations, as this study only included patients in whom HIV was detectable in the blood and the virus had already become resistant to drugs, and did not apply to “individuals who are being successfully treated with anti-HIV medications” (Reuters).

Hirschel suggests that as this new study is larger than a previous study that favoured STIs and includes clinical end-points, doctors “must go with the results of the large study” (Associated Press). A spokesperson for the Terrence Higgins Trust agreed that for anyone taking a drug holiday, it is important that they are “more closely monitored during that time” (BBC News Online).