Use of over-the-counter medications and natural products in patients with moderate and severe chronic renal insufficiency

Abstract

Background: Use of over-the-counter medications and natural products may be associated with drug-related problems among patients with chronic renal insufficiency. The aim of this study is to describe the use of nonprescription medications in patients attending a predialysis clinic and identify drug-related problems associated with the use of these products.

Methods: In a 6-month cluster randomized controlled trial, patients with moderate (n = 46) and severe (n = 41) chronic renal insufficiency were interviewed over the telephone at baseline by a community pharmacist to document their use of over-the-counter medications and natural products. The safety of each product was assessed, and drug-related problems were identified independently by 2 pharmacists.

Results: Overall, 83% (95% confidence interval [CI], 72 to 94) of patients with moderate chronic renal insufficiency and 68% (95% CI, 54 to 83) with severe chronic renal insufficiency reported using at least 1 over-the-counter medication. Contraindicated over-the-counter medications were reported by 9% of patients. Natural products were used by 22% (95% CI, 10 to 34) and 29% (95% CI, 15 to 43) of patients with moderate and severe chronic renal insufficiency, respectively. Similarly, 3% of patients reported using at least 1 contraindicated natural product. Patients had consulted a health professional for 49% of over-the-counter medications and 19% of natural products. Overall, 65 drug-related problems were identified.

Conclusion: The use of over-the-counter medications and natural products is highly prevalent in patients with chronic renal insufficiency and often is associated with a drug-related problem. These results emphasize the importance for community pharmacists to closely monitor the use of these products in patients with chronic renal insufficiency.