Drug	Usual dosage*	Dosage adjustments based on (percentage of usual dosage) GFR (mL per minute per 1.73 m2)
		> 50	10 to 50	< 10
Allopurinol (Zyloprim)†	300 mg daily	75%	50%	25%
Esomeprazole (Nexium)	No adjustment needed	—	—	—
Famotidine (Pepcid)	20 to 40 mg at bedtime	50%	25%	10%
Gabapentin (Neurontin)39	300 to 600 mg three times daily	900 to 3,600 mg three times daily (GFR= 60)	400 to 1,400 mg twice daily (GFR > 30 to 59) 200 to 700 mg daily (GFR > 15 to 29)	100 to 300 mg daily (GFR= 15)
Lansoprazole (Prevacid)	No adjustment needed	—	—	—
Metoclopramide (Reglan)	10 to 15 mg three times daily	100%	75%	50%
Omeprazole (Prilosec)	No adjustment needed	—	—	—
Ranitidine (Zantac)	150 to 300 mg at bedtime	75%	50%	25%