Fewer Pills Means Better Adherence and Viral Suppression, Analysis Finds
Today’s available HIV treatment regimens are simpler than ever before, with fewer pills and less-frequent dosing. However, “[l]ittle is known about the impact of once- vs. twice-daily antiretroviral therapy (ART) and pill burden on adherence and virologic outcomes,” notes a multinational research team in the January 22, 2014, online edition of Clinical Infectious Diseases.
Do dosing frequency and pill burden—the number of pills an individual must take daily—affect the ability of people with HIV to stick to a treatment regimen and see their HIV viral load suppressed? To address this question, the research team conducted a meta-analysis of 19 studies conducted between 2004 and 2011 with more than 6,300 individuals.
The results? Higher pill burden was significantly associated with reduced likelihood of achieving virologic suppression—an association that held for both once-daily treatment and twice-daily regimens. Higher pill burden was also linked with significantly lower rates of treatment adherence. This association was only significant for twice-daily combination regimens, however.
Looking at dosing frequency, adherence was higher with once-daily regimens compared to twice-daily therapy. However, rates of virological suppression did not differ significantly between once-daily and twice-daily treatment. Why?
The research team suggests that, as the effect of once-daily dosing on adherence was relatively limited (a 2.5% absolute increase in adherence), it was “possibly too small to result in a clinically meaningful difference in virologic suppression.” Also, they note, “volunteers for clinical trials are likely to be more adherent than their counterparts managed in routine clinical practice, and there may be more resources available to support adherence in clinical trial settings.” Due to these and other potential factors, “the difference in virologic suppression that we found between once- and twice- daily ART regimens may be underestimated.”
The authors stress the need to look beyond regimen simplification when choosing optimal antiretroviral therapy. “ART combinations should be selected based on factors such as tolerability, potential drug interactions, patient preference for dosing frequency and pill burden, as well as structural factors (e.g., cost, drug availability, access to care, insurance coverage),” they emphasize. (Click here for resources to help you get started on your first treatment regimen.)
In addition, the authors conclude, “[e]fforts to improve and sustain adherence should not be limited to regimen simplification, but consideration should be given to proven evidence-based interventions to improve adherence such as social support, adherence support toolkits (e.g., pillbox organizers), use of cell phone and/or text messages, treatment supporters, and other targeted interventions when necessary.” (Looking to boost your own adherence? Check out these tried-and-true tips and resources.)
The free, full-text research article is available online. For an in-depth discussion of the meta-analysis and its implications, see Michael Carter’s summary, excerpted below and available in full at AIDSmap.com.
Higher pill burden is associated with poorer adherence to HIV therapy and reduced chances of achieving an undetectable viral load
By Michael Carter
January 31, 2014
…The past decade has witnessed important improvements in antiretroviral treatment. Overall, drugs are now less toxic and better tolerated than in the past. Pill burden has also been reduced and dosing schedules simplified. Two fixed-dose pills (Atripla and Stribild) are now available, providing potent HIV therapy in a single tablet.
A meta-analysis of randomised trials published in 2009 showed that once-daily treatment was associated with higher rates of adherence compared to twice-daily therapy, but that rates of virologic suppression did not differ greatly between the treatment strategies.
More randomised trials have been published since then. An international team of investigators therefore re-visited the questions of whether pill burden and dosing schedule have an impact on adherence and virologic suppression.
Randomised-controlled trials comparing once- and twice-daily therapy published or presented before 31 March 2013 were eligible for inclusion in the analysis. The study populations could include people who had not taken treatment before (treatment naive); treatment-experienced people switching treatment with an undetectable viral load; or treatment-experienced people switching treatment with detectable viraemia….