From the Guidelines
In acute kidney injury (AKI), calcium channel blockers (amlodipine 5-10 mg daily, nifedipine XL 30-90 mg daily) and vasodilators (hydralazine 10-50 mg three to four times daily) are preferred antihypertensives as they don't require dose adjustments and don't worsen kidney function. Beta-blockers (metoprolol 25-100 mg twice daily) can also be used with caution. ACE inhibitors and ARBs should generally be avoided during acute kidney injury as they can further reduce glomerular filtration and worsen kidney function by dilating the efferent arteriole, as noted in the study by 1. However, it's worth noting that small elevations in serum creatinine (up to 30% from baseline) with renin-angiotensin system (RAS) blockers (such as ACE inhibitors and ARBs) must not be confused with AKI, and these medications should not be discontinued for minor increases in serum creatinine (<30%), in the absence of volume depletion, as stated in the study by 1. Loop diuretics like furosemide (20-80 mg IV or oral) may be used cautiously in volume-overloaded patients but require careful monitoring as they can worsen kidney perfusion if the patient becomes dehydrated. Blood pressure targets should be individualized, generally aiming for <140/90 mmHg, but avoiding excessive drops that could compromise kidney perfusion. Regular monitoring of kidney function, electrolytes, and volume status is essential when managing hypertension in AKI patients, with medication adjustments made based on clinical response and laboratory values. The most recent study by 1 provides guidance on the management of AKI in patients with cirrhosis, but its findings are not directly applicable to the general management of hypertension in AKI. Therefore, the preferred antihypertensives in AKI remain calcium channel blockers and vasodilators, with beta-blockers as an alternative, and careful consideration of the use of ACE inhibitors, ARBs, and loop diuretics.
From the FDA Drug Label
In hypertensive patients with normal kidneys who are treated with hydrALAZINE, there is evidence of increased renal blood flow and a maintenance of glomerular filtration rate. In some instances where control values were below normal, improved renal function has been noted after administration of hydrALAZINE However, as with any antihypertensive agent, hydrALAZINE should be used with caution in patients with advanced renal damage.
Hydralazine can be given in patients with Acute Kidney Injury (AKI), but it should be used with caution in patients with advanced renal damage 2.
From the Research
Antihypertensives in Acute Kidney Injury (AKI)
- The following antihypertensives can be considered in patients with AKI:
- Amlodipine: Studies have shown that amlodipine can have protective effects on renal function and reduce the risk of contrast-induced AKI in hypertensive patients 3.
- Cilnidipine: This N/L-type calcium channel blocker has been shown to reduce urinary albumin/creatinine ratio and suppress excessive uric acid formation in hypertensive patients with chronic kidney disease, making it a potential option for patients with AKI 4.
Considerations for Antihypertensive Use in AKI
- When using antihypertensives in patients with AKI, it is essential to consider the following:
- Fluid management: Aim for early, rapid restoration of circulatory volume, but avoid volume overload 5.
- Renal replacement therapy: Should only be started on the basis of hard criteria, but should not be delayed when criteria are met 5.
- Nephrotoxicity: Avoid nephrotoxic interventions, and consider the potential risks and benefits of different antihypertensives in patients with AKI 6.