Relation between number of prescribed medication and outcome in peritoneal dialysis patients

Many patients with end-stage renal disease need to take a large number of medications. In the present study, we studied the magnitude of problem and explored the relationship between the number of prescribed medications and the clinical outcome of a large cohort of prevalent peritoneal dialysis (PD) patients.

We studied the medication list of 266 prevalent PD patients. Dialysis adequacy, residual renal function and nutritional assessment were also performed. The patients were followed for 33.7 +/- 20.7 months.

On average, each patient required 4.7 +/- 1.8 type of medications or 10.0 +/- 4.9 tablets per day. 40 patients (15.0%) needed at least 7 types of medication; 33 patients (12.4%) had to take more than 15 tablets each day. There is a significant but weak correlation between the number of types of medication and the Charlson's comorbidity score (r = 0.252, p < 0.001). Despite the large number of medication prescribed, the blood pressure control, serum cholesterol level, and the use of aspirin after atherosclerotic disease remained suboptimal in many patients. By multivariate analysis, independent factors for patient survival were Charlson's comorbidity score, number of types of medication, duration of dialysis, overall SGA score, and mean arterial blood pressure. Each additional type of medication conferred 20% increase in risk of death (95% CI, 1.6-41.7%, p = 0.032), and the effect is independent on the Charlson's comorbidity score. The actual number of pills taken by a patient did not influence survival in this model.

Our results indicate that the number of prescribed medications is related to the clinical outcome of PD patients. The number of prescribed medication may reflect the severity of uremic complications and comorbid diseases not reflected by the Charlson's comorbidity score. Nevertheless, dialysis physicians should carefully balance the clinical need of treating multiple medical conditions with the potential problems of a complicated therapeutic regimen.