What is the concern with an 84-year-old female's medication regimen and impaired renal function, with a TSH of 0.151, on lisinopril, metoprolol, and levothyroxine?

From the Guidelines

The patient's lisinopril dose should be reduced from 40 mg to 20 mg daily, and her levothyroxine dose should be reduced from 125 mcg to 100 mcg, due to her declining kidney function and suppressed TSH level, as indicated by studies such as 1 and 1. The patient's declining kidney function, as evidenced by a drop in eGFR from 74 to 47 and an elevated creatinine of 1.3, requires immediate attention. According to the national kidney foundation practice guidelines for chronic kidney disease, a GFR level less than 60 mL/min per 1.73 m2 represents loss of half or more of the adult level of normal kidney function, and the prevalence of complications of chronic kidney disease increases at lower levels of GFR 1.

Medication Adjustments

• Reduce lisinopril dose from 40 mg to 20 mg daily to minimize potential nephrotoxicity, as ACE inhibitors can worsen kidney function, especially in elderly patients.
• Reduce levothyroxine dose from 125 mcg to 100 mcg, as the patient's suppressed TSH level of 0.151 indicates overtreatment of hypothyroidism.
• Continue metoprolol at the current dose of 50 mg, but closely monitor blood pressure.

Additional Recommendations

• Increase fluid intake to help maintain kidney function.
• Avoid NSAIDs, which can further worsen kidney function.
• Repeat renal function tests in 2 weeks to assess response to medication adjustments.
• Monitor the patient for symptoms of hypothyroidism after reducing levothyroxine and for changes in blood pressure after reducing lisinopril.
• Schedule a follow-up appointment in 2-4 weeks to reassess thyroid and kidney function.

From the FDA Drug Label

5.3 Impaired Renal Function Monitor renal function periodically in patients treated with lisinopril. Changes in renal function including acute renal failure can be caused by drugs that inhibit the renin-angiotensin system. Patients whose renal function may depend in part on the activity of the renin-angiotensin system (e.g., patients with renal artery stenosis, chronic kidney disease, severe congestive heart failure, post-myocardial infarction or volume depletion) may be at particular risk of developing acute renal failure on lisinopril. Consider withholding or discontinuing therapy in patients who develop a clinically significant decrease in renal function on lisinopril [see Adverse Reactions (6. 1), Drug Interactions (7.4)].

The patient's eGFR decreased from 74 to 47 and her creatinine is 1.3, indicating a decline in renal function.

• The patient is at risk of developing acute renal failure due to the use of lisinopril.
• Monitoring of renal function is necessary, and consideration should be given to withholding or discontinuing lisinopril therapy due to the significant decrease in renal function 2.
• Dose adjustment of lisinopril may be required in patients with renal impairment 2.

From the Research

Patient's Current Condition

• The patient is an 84-year-old female with hypertension (HTN) and hypothyroidism, currently taking 40 mg of lisinopril, 50 mg of metoprolol, and 125 mcg of levothyroxine.
• Her current TSH level is 0.151, indicating that her hypothyroidism is being managed.
• However, her eGFR has decreased from 74 to 47, and her creatinine level is 1.3, suggesting a decline in kidney function.

Kidney Function Decline

• A study published in 2012 3 found that a decline in eGFR of 25% or more over a 1-year period is associated with an increased risk of end-stage renal disease (ESRD).
• Another study published in 2014 4 found that a decline in eGFR of 30% or 40% is strongly associated with the subsequent development of established kidney outcomes, including ESRD.
• The patient's decline in eGFR from 74 to 47 represents a decrease of approximately 36%, which may indicate a significant decline in kidney function.

Lisinopril and Kidney Function

• Studies published in 1987 5 and 1988 6 found that lisinopril, an angiotensin-converting enzyme inhibitor, is effective in lowering blood pressure in patients with impaired renal function and does not significantly affect kidney function.
• However, these studies did not specifically examine the effect of lisinopril on kidney function decline in patients with a significant decrease in eGFR.

Management of Kidney Function Decline

• The patient's decline in kidney function should be closely monitored, and her medication regimen should be adjusted as needed to slow the progression of kidney disease.
• The use of alternative medications, such as calcium channel blockers, may be considered to help manage the patient's blood pressure and slow kidney function decline 7.