Medication	Dosage adjustment based on GFR (mL per minute per 1.73 m2 )*
	> 50	10 to 50	< 10
Acyclovir (Zovirax; oral)	100%	100%	200 mg every 12 hours
Allopurinol (Zyloprim)	75%	50%	25%
Amoxicillin	Every 8 hours	Every 8 to 12 hours	Every 24 hours
Amoxicillin/clavulanate (Augmentin)	Every 12 hours	Estimated GFR 10 to 30 mL per minute per 1.73 m2: every 12 hours	Every 24 hours
		Estimated GFR < 30 mL per minute per 1.73 m2: do not use 875-mg/125-mg tablets
Atenolol (Tenormin)	100%	50%	25%
Cefazolin	Every 8 hours	Every 12 hours	50% every 24 to 48 hours
Cephalexin (Keflex)	Every 8 hours	Every 8 to 12 hours	Every 12 to 24 hours
Ciprofloxacin (Cipro)	100%	50 to 75%	50%
Clarithromycin (Biaxin)	100%	50 to 100%	50%
Famotidine (Pepcid)	50%	25%	10%
Fluconazole (Diflucan)	100%	50%	50%
Gabapentin (Neurontin)	Estimated GFR 30 to 60 mL per minute per 1.73 m2: 200 to 700 mg twice daily
	Estimated GFR 16 to 29 mL per minute per 1.73 m2: 200 to 700 mg daily
	Estimated GFR ≤ 15 mL per minute per 1.73 m2: 100 to 300 mg daily
Glyburide	100%	Avoid	Avoid
Levofloxacin (Levaquin)	100%	Estimated GFR 20 to 49 mL per minute per 1.73 m2: 500- to 750-mg initial dose, then 250 to 750 mg every 24 to 48 hours	—
		Estimated GFR 10 to 19 mL per minute per 1.73 m2: 500-mg initial dose, then 250 to 500 mg every 48 hours
Metformin (Glucophage)	Avoid if serum creatinine level is greater than 1.5 mg per dL (132.60 μmol per L) in men or greater than 1.4 mg per dL (123.76 μmol per L) in women, and in patients older than 80 years
Metoclopramide (Reglan)	100%	75%	50%
Ranitidine (Zantac)	75%	50%	25%
Rosuvastatin (Crestor)	—	GFR < 30 mL per minute per 1.73 m2: 5 mg per day initially; 10 mg per day maximum
Simvastatin (Zocor)	—	GFR < 30 mL per minute per 1.73 m2: 5 mg per day initially
Thiazide diuretics†	100%	100%	Avoid
Valacyclovir (Valtrex)	100%	Every 12 to 24 hours	500 mg every 24 hours