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Drs. Chahine and Brown are both assistant professors of pharmacy practice at Palm Beach Atlantic University, Lloyd L. Gregory School of Pharmacy, West Palm Beach, Florida.

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In general, kidney failure refers to any circumstance that impacts the kidney's ability to function appropriately. Many conditions, diseases, and medications can instigate situations leading to either acute or chronic kidney disease (CKD).

Acute renal failure is frequently reversible and associated with dehydration, blood loss from surgery, or exposure to contrast agents or medications such as nonsteroidal anti-inflammatory drugs. CKD is predominantly nonreversible and is due to long-term, uncontrolled comorbidities, thus forcing patients with this condition to move through many facets of the health care system.^1-4

CKD is a growing public health concern that remains underdiagnosed in the United States.³ The early stages of CKD and the incidence and prevalence of kidney failure are escalating due in part to an aging American population and an increasing rate of incidence of diabetes.⁵ Data from the National Health and Nutrition Examination Survey suggest that the prevalence of CKD has increased, from 12.9% in the period between 1988 and 1994, to 15.5% in the period between 1999 and 2004.^6,7 Presently, more than 30 million Americans have been diagnosed with CKD, which is associated with an increased risk for cardiovascular disease, progression to endstage renal disease (ESRD), and sudden death. In fact, by 2030, more than 2.2 million Americans will warrant treatment for ESRD, causing a significant burden on the health care system.⁶

CKD may be detected in either the outpatient or inpatient setting. In the ambulatory setting, CKD is found as a result of typical comprehensive management and screening for diseases such as diabetes, heart failure, and hypertension. When these conditions go uncontrolled, they can lead to hospital admission for acute decompensated heart failure, hypertensive crises, diabetic ketoacidosis, or acute coronary syndromes, where CKD is then diagnosed.⁴ The National Kidney Foundation Kidney Disease Outcomes Quality Initiative (KDOQI) Advisory Board defines CKD as either:

1. Kidney damage for ≥3 months, indicated by structural or functional abnormalities of the kidney, with or without decreased glomerular filtration rate (GFR), manifested by abnormalities or markers of kidney damage, including abnormalities in the composition of the blood or urine, or abnormalities in imaging test results, or
2. GFR <60 mL/min/1.73 m² for ≥3 months, with or without kidney damage

KDOQI also established a 5-stage classification system of CKD progression, defined according to GFR and the presence or absence of kidney damage (Table).³

Once discharged from the hospital, patients diagnosed with CKD may be followed by their primary care provider and/or a consulting nephrologist, depending upon the stage of disease. In patients with Stage 4 disease or higher, a nephrologist typically manages care, as renal replacement therapy (RRT) may be warranted. All patients should receive consultations from a clinical dietitian, certified diabetes educator (if diabetes is a comorbidity), and case manager/social worker who will coordinate overall care. Input from a cardiologist or endocrinologist also may be needed, depending upon the severity of cardiovascular comorbidities and diabetes.⁸

For all patients with CKD, blood pressure should be tightly controlled to a goal of <130/80 mm Hg; hemoglobin A1C reduced to <7%; a low-density lipoprotein concentration decreased to <100 mg/dL; and proteinuria significantly diminished.³ Medications used to reach these goals include an angiotensin-converting enzyme inhibitor, angiotensin receptor blocker, calcium channel blocker, and/or beta-blockers, sulfonylureas, insulin sensitizers and/or insulin, and lipid-lowering agents such as a statin. Selection of specific agents will depend upon comorbidities and drug contraindications. Lifestyle modifications, such as smoking cessation, exercise, and dietary changes, which could include a diet low in sodium and phosphorus, should be carefully implemented.

In patients with Stage 3 disease or higher, drugs to treat anemia (eg, iron replacement products, erythropoietin, or darbepoetin alfa), hyperparathyroidism/ vitamin D deficiency (eg, vitamin-D sterol therapy), and/or hyperphosphatemia (eg, phosphate binders) will need to be considered. At Stage 4, patients will need to consider the possibility of transplantation and begin planning for dialysis. For Stage 5 or ESRD, a surgeon should be consulted for the placement of a permanent vascular access graft so that RRT can be started.

The pharmacist plays a crucial role, as he or she is the only clinician who remains the constant among all the different providers and consultants making recommendations of care for the CKD patient. The pharmacist will need to pay close attention for drug–drug and drug–disease interactions, drug duplications, and adverse drug reactions. As many patients tend to take nutritional supplements without informing their providers, the pharmacist will need to educate the patient with CKD on which nutritional supplements to avoid. Overall, pharmacists practicing in various health systems may be faced with many possible concerns as the patient moves through the health care system.

Stages and Prevalence of CKD Based on NKF-KDOQI and Possible Opportunities for Interventions
Stage	Description	GFR (mL/min/1.73 m2)	Prevalence(%)	Possible Interventions
1	Kidney damage with normal GFR or GFR >90	≥90	3.3	Screening and identification; aggressive treatment of comorbid conditions (DM, HTN, hyperlipidemia)
2	Kidney damage with mild decrease in GFR	60 to 89	3.0
3	Moderate decrease in GFR	30 to 59	4.3	Testing and treatment for common complications of CKD (anemia, hyperparathyroidism, hyperphosphatemia)
4	Severe decrease in GFR	15 to 29	0.2	Planning for renal dialysis and transplantation
5 or ESRD	Kidney failure	<15 or dialysis	0.1	Permanent vascular access and initiation of RRT
CKD = chronic kidney disease; NKF-KDOQI = National Kidney Foundation Kidney Disease Outcome Quality Initiative; GFR = glomerular filtration rate; DM = diabetes mellitus; HTN = hypertension; ESRD = end-stage renal disease; RRT = renal replacement therapy. Adapted from references 3 and 4.

Unique Continuity of Care Concerns Once the patient is admitted to the hospital, the inpatient pharmacist should make recommendations for aggressive pharmacotherapy of comorbidities and adjustment in medication doses per the patient's renal function; evaluation of objective findings for common complications of CKD, such as anemia and hyperphosphatemia, will be crucial. Nurses may need to be educated regarding appropriate scheduling of medications to avoid possible drug–drug interactions. After stabilization and prior to discharge, the patient may have questions regarding side effects of medications, appropriate medication dosing schedules, pharmacotherapy goals, and diet. The pharmacist should work with the medical team to find cost-effective medication regimens to which the patient can adhere. Questions also may arise regarding appointments with specialists, such as cardiologists, nephrologists, and endocrinologists. Once discharged to home, the community-based pharmacist can work with the patient to enhance adherence to medications, explain therapeutic goals, select appropriate smoking cessation strategies (if needed), and answer additional questions regarding diet and supplements to avoid. In some cases, patients may require dialysis; the pharmacist practicing in this setting will need to make recommendations regarding medication scheduling and dosing, especially for medications not familiar to the nephrologist, around the patient's dialysis regimen. It will be crucial that the primary care provider knows all the specialty clinicians who are providing consultations; the pharmacist can inform the primary provider if duplications in pharmacotherapy exist.

References

1. Coresh J, Astor BC, Greene T, Eknoyan G, Levey AS. Prevalence of chronic kidney disease and decreased kidney function in the adult US population: Third National Health and Nutrition Examination Survey. Am J Kidney Dis. 2003;41(1):1-12.
2. St Peter WL, Khan SS, Ebben JP, Pereira BJ, Collins AJ. Chronic kidney disease: the distribution of health care dollars. Kidney Int. 2004;66:313-321.
3. KDOQI clinical practice guidelines for chronic kidney disease: evaluation, classification, and stratification. Am J Kidney Dis. 2002;39:S1-266.
4. Chen RA, Scott S, Mattern WD, Mohini R, Nissenson AR. The case for disease management in chronic kidney disease. Dis Manag. 2006;9:86-92.
5. Foley RN, Murray AM, Li S, et al. Chronic kidney disease and the risk for cardiovascular disease, renal replacement, and death in the United States Medicare population, 1998 to 1999. J Am Soc Nephrol. 2005;16:489-495.
6. Bakris GL. Protecting renal function in the hypertensive patient: clinical guidelines. Am J Hypertens. 2005;18:112S-119S.
7. Kopyt NP. Chronic kidney disease: the new silent killer. J Am Osteopath Assoc. 2006;106:133-136.
8. Go AS, Chertow GM, Fan D, McCulloch CE, Hsu CY. Chronic kidney disease and the risks of death, cardiovascular events, and hospitalization. N Engl J Med. 2004;351:1296-305.