Search

Background A clinical trial comparing the rate of discontinuation and tolerability of two post-exposure prophylaxis (PEP) regimens was performed. Methods A total of 255 individuals attending the emergency rooms of six hospitals for exposure to HIV and criteria to receive PEP were randomized to receive zidovudine/ lamivudine plus either lopinavir/ritonavir ( n=131) or atazanavir ( n=124; day 0). The primary end point was the rate of PEP discontinuation before day 28 of follow-up. Secondary end points were incidence of side effects, follow-up at days 90 and 180 and rate of seroconversions. Results A total of 55 patients (29 in lopinavir/ritonavir and 26 in atazanavir arms) did not attend the first scheduled appointment (day 1) and were excluded from the analysis. The rate of discontinuation before day 28 owing to any cause was similar between groups (37/102 [36%] in lopinavir/ritonavir and 35/98 [36%] in atazanavir arms, P=0.82). Adverse events were the reason for discontinuation or switching of PEP in 33 individuals (16/102 [16%] in the lopinavir/ritonavir arm and 17/98 [17%] in the atazanavir arm, P=0.84). Adverse events were reported in 92/200 (46%) of individuals on PEP who attend at least the day 1 appointment (50/102 [49%] in the lopinavir/ ritonavir arm and 42/98 [43%] in the atazanavir arm, P=0.38). There were no seroconversions. Conclusions The rate of discontinuation of PEP before day 28 was similar with zidovudine/lamivudine plus either lopinavir/ritonavir or atazanavir. The rate of discontinuation of PEP because of adverse events was low in both arms. Almost 50% of the patients of both arms suffered side effects. New strategies are needed to improve the tolerance.

IntroductionAlternation of antiretroviral drug regimens has been proposed as a novel treatment strategy for HIV infection. However, some concerns persist regarding antiviral efficacy, adherence, toxicity and resistance evolution in the long term.MethodsA total of 161 antiretroviral-naive HIV-1-infected patients were randomized to receive stavudine/ didanosine/efavirenz (group A) or zidovudine/lamivudine/ nelfinavir (group B) or to alternate between the two regimens every 3 months starting with regimen A (group C). Antiviral efficacy, adherence, safety and tolerability were analysed every 12 weeks.ResultsAfter 96 weeks, time to virological failure was significantly delayed in the alternating regimen compared with the standards of care regimens. Virological suppression was seen in 46%, 48% and 58% of patients in groups A, B and C, respectively, in the intention-to-treat analysis and in 75%, 76% and 97% in the on-treatment analysis (A vs C: P=0.014; B vs C: P=0.016; A vs B: P=0.849). At the end of the study, 94% of patients in group A and 92% in groups B and C reported an adherence greater than 95%. Alternating therapy was associated with a similar impact on CD4+ counts in comparison with the standards of care regimens, as well as a lower mitochondrial DNA/nuclear DNA (mtDNA/nDNA) ratio decrease in the mitochondrial substudy performed on 37 patients. The frequency and intensity of adverse events in the alternating group decreased during subsequent cycles.DiscussionOur results favour the hypothesis that proactive therapy switching may delay the accumulation of resistance mutations. Moreover, the alternating regimen was well tolerated and adherence remained comparably high in all treatment groups. The lower mtDNA/nDNA ratio decrease observed in this group may imply a lower impact on mitochondrial toxicity than in standard regimens.

Alternation of antiretroviral drug regimens has been proposed as a novel treatment strategy for HIV infection. However, some concerns persist regarding antiviral efficacy, adherence, toxicity and resistance evolution in the long term.A total of 161 antiretroviral-naive HIV-1-infected patients were randomized to receive stavudine/didanosine/efavirenz (group A) or zidovudine/lamivudine/ nelfinavir (group B) or to alternate between the two regimens every 3 months starting with regimen A (group C). Antiviral efficacy, adherence, safety and tolerability were analysed every 12 weeks.After 96 weeks, time to virological failure was significantly delayed in the alternating regimen compared with the standards of care regimens. Virological suppression was seen in 46%, 48% and 58% of patients in groups A, B and C, respectively, in the intention-to-treat analysis and in 75%, 76% and 97% in the on-treatment analysis (A vs C: P=0.014; B vs C: P=0.016; A vs B: P=0.849). At the end of the study, 94% of patients in group A and 92% in groups B and C reported an adherence greater than 95%. Alternating therapy was associated with a similar impact on CD4+ counts in comparison with the standards of care regimens, as well as a lower mitochondrial DNA/nuclear DNA (mtDNA/nDNA) ratio decrease in the mitochondrial substudy performed on 37 patients. The frequency and intensity of adverse events in the alternating group decreased during subsequent cycles.Our results favour the hypothesis that proactive therapy switching may delay the accumulation of resistance mutations. Moreover, the alternating regimen was well tolerated and adherence remained comparably high in all treatment groups. The lower mtDNA/nDNA ratio decrease observed in this group may imply a lower impact on mitochondrial toxicity than in standard regimens.