Managing chronic kidney disease (CKD) and the potential for myriad related comorbid conditions can pose several challenges to nephrologists and other providers, as one of the most common conditions stemming from CKD is hypertension.
"The kidney is a critical organ in regulating blood pressure and does this through multiple mechanisms," Crystal Gadegbeku, MD, of the Lewis Katz School of Medicine at Temple University in Philadelphia, explained to 鶹ý. "Therefore, many patients with kidney disease have, what we call, 'resistant hypertension,' meaning they need three or more medications just to optimally control their blood pressure."
Medication Management
But because these patients will likely suffer from other medical issues, similarly related to their kidney disease like heart disease, diabetes, and gout, concomitant drug managment is one of the top challenges facing clinicians and patients.
"Studies show that patients with kidney disease have an average of 12 medications, many of which have different dosage schedules," Gadegbeku pointed out. "This can be very expensive for patients, cause confusion, and can contribute to non-adherence. Further, there are over-the-counter medications that can worsen blood pressure, and the progression of kidney disease can make management more difficult."
Jeffrey Berns, MD, of the Hospital of the University of Pennsylvania in Philadelphia, agreed, telling 鶹ý that three of the top challenges of managing patients with CKD and hypertension are medication adherence, medication costs, and dealing with the accompanying side effects of said drugs.
In order to successfully manage CKD and hypertension, providers need to be especially watchful, advised Matthew Sparks, MD, of Duke Health in Durham, North Carolina.
"Side effects of medication are more prominent in this population," he told 鶹ý. "Meticulous attention to volume status, potassium homeostasis, electrolyte abnormalities, and kidney function is needed."
More frequent follow-up of these patients would prove beneficial, particularly when initiating new medications or increasing existing doses, Sparks continued. In addition, because of the constant changes in pill management for these patients, it's especially important to continually -- and more importantly accurately -- monitor blood pressure to note any fluctuations or changes, he said.
Treatment Strategies
In patients with CKD and hypertension, treatment is needed to prevent progression of the disease, manage blood pressure, and prevent cardiovascular disease, according to the .
Gadegbeku pointed out that although there is some controversy about optimal blood pressure targets, a good rule is to follow the American Heart Association and American College of Cardiology's most recent guidelines, which suggest that patients with kidney disease should have a goal blood pressure less than 130/80 mm Hg.
After diet changes, such as cutting back on sodium, saturated fats, and cholesterol, the most common first-line medications for managing hypertension in CKD include angiotensin-converting enzyme inhibitors (ACEIs) -- such as benazepril (Lotensin), captopril (Capoten), and enalapril (Vasotec) -- and angiotensin II receptor blockers (ARBs) like valsartan (Diovan), losartan (Cozaar), azilsartan (Edarbi), and olmesartan (Benicar). These medications are especially beneficial for patients with kidney disease associated with protein in the urine since ACEIs and ARBs can lower urinary protein, said Gadegbeku.
Additional medications may be subsequently added if the target blood pressure is still not achieved. Sparks pointed out, however, that the largest body of evidence that exists for choosing a specific class of medication is when treating hypertension in patients with CKD with diabetic nephropathy or those who have proteinuria, regardless of the etiology of kidney disease. "In these patients, we utilize -- ARBs, or ACEIs," he explained.
"Volume control is also an important consideration in treating patients with CKD and hypertension," Sparks continued. "Depending upon the degree of CKD, patients can be treated with a thiazide diuretic, or in more advanced CKD with evidence of volume overload, a loop diuretic might be indicated. In both of these instances, it is important to ensure euvolemia and monitor electrolytes and kidney function."
However, Berns highlighted that prescribing some of these treatments have proved a challenge within themselves, due to the recent FDA recalls of many ARBs for possible contamination.
What to Watch For
Particularly when prescribing ACEIs to patients with CKD, high potassium levels -- i.e., hyperkalemia -- is one possible side effect to especially watch for, since this can be life-threatening, Gadegbeku warned. "These agents often cause a slight drop in kidney function that is associated with long-term preservation of kidney function, so a nephrologist must observe this effect and weigh the risks and benefits of the therapy."
"Patients with low blood pressure should be cautious to use ACEIs or ARBs," Sparks suggested. He also noted that providers should be aware of any potential large increases in creatinine in addition to the risk for recurrent hyperkalemia not mitigated through diet or medical management, after receiving an ACEI or ARB.
Also concerning, although rare, is angioedema in addition to hyperkalemia, especially when dealing with ACEIs, Berns noted.
Another rare but serious side effect is the risk of a possible severe life-threatening allergic reaction to ACEIs, Gadegbeku said. "A common but not very serious consequence is that people can develop a nagging cough with ACE inhibitors." Cough and allergic reactions, however, are less commonly seen with ARBs.