• Patient adherence with twice-daily dosing of nelfinavir (NLF) equivalent to non-nucleoside reverse transcriptase inhibitors (NNRTI) when given in combination with dual nucleoside analogues (NRTI) (Poster, ThPeB4991)
  Authored by A. Luber, J. Mulnick, S. Raber, M. Sherman (United States)
• Study of adherence to highly active antiretroviral treatment (HAART) in a sample of HIV-infected patients (Poster, ThPeB5002)
  Authored by Rubio, et al. (Spain)

It's unclear what more we can say about adherence that has not already been said. We seem to know fairly well how important it is to be adherent. The virus is not suppressed unless the drugs are taken. Every day. Every dose. The consequences of failing to do so can be profound: viral dissemination and disease progression, the development of resistance to the antiretroviral drugs (and even cross-resistance to drugs never taken). In spite of these consequences non-adherence is common. This week we've seen from several creative reports just how common non-adherence really is. In some studies up to half of patients either occasionally or regularly failed to take their daily dosages. In the study from Vancouver a substantial percentage failed to even pick up their medications from the pharmacy (where they were provided free-of-charge). We have seen few studies of strategies to improve adherence. Unfortunately, I still do not have much to report in this area from Thursday.

Patient adherence with twice-daily dosing of nelfinavir (NLF) equivalent to non-nucleoside reverse transcriptase inhibitors (NNRTI) when given in combination with dual nucleoside analogues (NRTI) (Poster, ThPeB4991)

In this study, patient adherence with twice-daily (BID) dosing of nelfinavir was equivalent to adherence to non-nucleoside RTI (NNRTI) when given in combination with dual nucleosides (NRTI). The authors here used an anonymous adherence questionnaire for adherence assessment at three centers in California. They evaluated over 200 patient-responses. In spite of a larger pill burden with NFV, adherence to NFV when given BID was equivalent to the adherence achieved with the NNRTI-containing regimens -- even regimens with once-daily NNRTI dosing (such as with efavirenz). This suggests to the authors (and to me) that prescribing regimens that can be taken twice daily should be our immediate goal. QD dosing may not necessarily hold much additional benefit with respect to adherence for most patients.

Study of adherence to highly active antiretroviral treatment (HAART) in a sample of HIV-infected patients (Poster, ThPeB5002)

The poster from Rubio, et al. from Madrid is another look at adherence. Their measure of adherence was similar to the Vancouver study discussed earlier: the dispensing/receipt of prescriptions in a program where antiretrovirals are given without charge. In spite of removing what is thought to be a major barrier to adherence, namely cost of the drugs, many of these patients were grossly non-adherent. Specifically one-third of the patients failed to pick up even 80% of the antiretroviral drugs prescribed, and only slightly more than half (53%) actually picked up 90% of their prescriptions. The importance of this study and the Vancouver study is two fold. First, non-adherence seems even worse than I imagined (especially in a setting with free medications) and second, pharmacy records seem to be an easy way to track adherence.