Drug General Information (ID: DDIJB6VC93)
Drug Name			Sevelamer		Drug Info		Nalidixic acid		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Phosphate Binders				Antibiotics
Structure

Mechanism of Sevelamer-Nalidixic acid Interaction (Severity Level: Moderate)
Complex formation Click to Show/Hide Mechanism Graph
Drug Name		Sevelamer				Nalidixic acid
Mechanism		Anion exchange resin/polymer				Binds to anion exchange resin/polymer
Key Mechanism Factor 1
		Factor Name		Chelation
		Factor Description		Chelation is a direct drug interaction that usually involves the formation of dimers or trimers, resulting in larger complexes and poorer absorption.
Mechanism Description		Decreased absorption of Sevelamer due to formation of complexes caused by Nalidixic acid

Recommended Action
Management		Oral quinolone antibiotics should not be administered simultaneously with sevelamer hydrochloride. The optimal length of time needed to separate ingestion of these drugs is currently unknown. Based on the fact that it took up to 4 hours to achieve ciprofloxacin Cmax in all 15 volunteers of the study, the authors suggested a separation time of at least 4 hours between sevelamer and ciprofloxacin administration to reduce the likelihood of a significant interaction, particularly in patients with end-stage renal disease whose gastrointestinal motility may be slowed.

References
1	Kays MB, Overholser BR, Mueller BA, Moe SM, Sowinski KM "Effects of sevelamer hydrochloride and calcium acetate on the oral bioavailability of ciprofloxacin." Am J Kidney Dis 42 (2003): 1253-9. [PMID: 14655198]