1. Prolonged use of nitrofurantoin can worsen kidney function, limiting its use in patients with reduced GFR. They should be closely monitored if use is necessary.

2. Chronic use of nitrofurantoin may lead to fibrosis and reduced renal function. For patients with chronic kidney disease, dosage adjustments and regular kidney function tests are recommended.

3. Long-term nitrofurantoin can cause decreased kidney function by inducing interstitial fibrosis. CKD patients must consult healthcare providers for alternative treatments or dose adjustments.

4. Extended nitrofurantoin usage can impair kidney function, presenting risks for CKD patients. Such patients should use it cautiously under medical supervision, with frequent renal assessments.

5. Over time, nitrofurantoin may reduce kidney efficiency due to fibrotic changes, making it risky for chronic kidney disease patients who should use lower doses or alternatives based on physician advice.