Kidney disease, prostate cancer, and OTC products
Can certain OTC medications contribute to kidney disease? What supplements could increase the risk of prostate cancer? This month I discuss potential urologic risks associated with some commonly used OTC products and offer recommendations for patient education.
With the recent introduction of OTC esomeprazole magnesium (Nexium—Pfizer), three distinct proton pump inhibitor (PPI) medications and various generics are now available without a prescription. Many patients have positive outcomes with these medications without a physician appointment. However, there are risks to consider, and kidney disease is one that has been recently reported.
A recent retrospective analysis of 133 cases of acute interstitial nephritis (AIN) found drugs to be the leading culprit in 70% of cases, and of those, omeprazole (Prilosec—AstraZeneca) was the causative agent in 12% of patients. Patients using omeprazole were older and had better baseline renal function and a longer duration of PPI use compared with cases of AIN not related to drug therapy.1 Similar data were found in a case control study in New Zealand.2
What does this mean in the self-care environment? Take advantage of opportunities to talk with patients about the appropriate way to use an OTC PPI, and discuss potential adverse reactions, including back pain, fever, blood in the urine, decreased urine output, and weight gain.
A number of studies have been published recently that discuss NSAID use in patients with kidney disease. In one study of 185 patients with chronic kidney disease, the authors determined how many took what was considered an inappropriate medication based on dosing recommendations in the package insert, which in turn were based on calculated creatinine clearance. More than 80% of those surveyed used at least one inappropriate medication, and of those, 66% were using an NSAID.3
When counseling patients on NSAID use, be sure to verify that the patient doesn’t have any type of renal dysfunction. Also, when dispensing medications that are commonly prescribed to patients with renal disease, counsel about the risks of using an OTC NSAID.
Vitamin E is a very popular supplement with antioxidant properties. It is used by many people for various reasons, yet there is little supportive evidence for its efficacy. Alpha tocopherol, one form of vitamin E, is the primary version available in supplements and the only form for which a recommended daily allowance has been established.
Selenium is also used for its antioxidant properties, and it too is commonly used by people for various reasons. Often these two supplements are used together with the thought that both have antioxidant properties and may offer benefit through synergistic actions.
However, recent data suggest that these supplements could increase prostate cancer risk. In one recent study, selenium supplementation was found to increase the risk of high-grade prostate cancer (91%) in men with high baseline selenium.
Vitamin E also increased overall risk of prostate cancer (63%) in men with low baseline selenium.4 Other research supports these findings.5,6 On the basis of these data, one study author (A.R. Kristal4) suggested that “men using these supplements should stop, period. Taking a broad view of the recent scientific studies, there is an emerging consistency about how we think about optimal intake of micronutrients. There are optimal levels, and these are often the levels obtained from a healthful diet, but either below or above the levels there are risks.”
- Am J Kidney Dis. 2014. doi: 10.1053/j.ajkd.2014.04.027. [Epub ahead of print]
- Kidney Int. doi: 10.1038/ki.2014.74. [Epub ahead of print]
- Renal Fail. 2013;35(6)906–10
- J Natl Cancer Inst. doi:10.1093/jnci/djt456. [Epub 2014 Feb 22]
- Nutr Metab (Lond). doi: 10.1186/1743-7075-11-30. [eCollection 2014]
- Cancer Prev Res (Phila). pii:canprevres. 0058.2014. [Epub ahead of print]