Survey: Dialysis Patients Take the Most Pills of Any Chronic Disease

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Dialysis Patients Take the Most Pills
By Crystal Phend, Staff Writer, MedPage Today
Published: May 07, 2009

Reviewed by Dori F. Zaleznik, MD; Associate Clinical Professor of Medicine, Harvard Medical School, Boston.

SAN FRANCISCO, May 7 -- At an average of 19 pills a day, dialysis patients may have the highest pill burden seen in any chronic disease.

The high number of phosphate binders and other drugs taken daily by dialysis patients may impact their quality of life, said researchers led by Rajnish Mehrotra, M.D., of the University of California Los Angeles.

A quarter of the 233 chronic dialysis patients in their study took at least 25 pills each day, the investigators reported online in the Clinical Journal of the American Society of Nephrology.

One patient downed 70 a day, Dr. Mehrotra said.

Although pill burden is best known as an issue in HIV/AIDS treatment because of the dozens of tablets patients had to take in early regimens, most regimens now include fewer than 20 pills a day.

The average for diabetes mellitus is two to four pills a day and for congestive heart failure is 10 to 11, the researchers noted.

Dialysis patients have a high burden of coexisting diseases that require medication, but the single largest contributor to pill burden in the study was phosphate binders, the researchers noted.

The patients in the cross-sectional study done at three university-affiliated dialysis units across the country took a mean of 11 different medications, including two parenteral drugs on average.

Phosphate binders accounted for 49% of the daily pill burden, which exceeded 10 in 91% of the dialysis patients, 20 in 47%, and more than 30 in 17%.

Higher total pill burden was independently associated with lower health-related quality of life on the physical subscale of the SF 36 questionnaire in the multivariate analysis (P0.001).

Other significant factors in physical health-related quality of life were greater comorbidity and lower serum albumin.

Surprisingly, the psychological effect of pill burden did not appear to be significant. The mental component of health-related quality of life did not correlate with pill burden in either the univariate or multivariate analyses.

The only mental health-related quality of life predictors were lower serum phosphorus level and shorter duration on dialysis (P0.01).

"It is tempting for us to speculate that a high pill burden makes people feel worse because they have all the attendant side effects of medication," Dr. Mehrotra said.

But he noted that in this type of study confounding can never be eliminated with certainty, and the lack of effect on the mental health component suggested that pill burden might have been a surrogate for more severe disease.

However, it's likely that the association reflects both reasons, Dr. Mehrotra said.

Overall median medication adherence was 72%, but only 38% of patients were fully adherent to the prescribed phosphate binder therapy.

Both total pill burden and phosphate binder pill burden were linked to lower adherence (P=0.03 and P=0.003, respectively) with a threshold of 12 for phosphate binders.

However, taking more phosphate binders was not linked to lower serum phosphate levels.

"It appears reasonable to conclude that reducing pill burden may improve patient adherence," the investigators said, although they acknowledged that the study could not determine whether that would be the case.

Since frequency of phosphate binders cannot be reduced, choosing an agent that requires fewer pills may be prudent, as would attention to causes of out-of-range phosphate levels, such as diet, Dr. Mehrotra said.

The study was funded by a grant from Shire Pharmaceuticals, the makers of the phosphate binder lanthanum carbonate.

Dr. Mehrotra reported grant support and honoraria from Shire Pharmaceuticals as well as conflicts of interest with Amgen, Baxter Health Care, and Novartis.

Primary source: Clinical Journal of the American Society of Nephrology
Source reference:
Chiu Y-W, et al "Pill burden, adherence, hyperphosphatemia, and quality of life in maintenance dialysis patients" Clin J Am Soc Nephrol 2009.