Drug General Information (ID: DDIFV4YO5L)
Drug Name			Trovafloxacin		Drug Info		Didanosine		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Antiinfective Agents				Anti-Hiv Agents
Structure

Mechanism of Trovafloxacin-Didanosine Interaction (Severity Level: Moderate)
Complex formation Click to Show/Hide Mechanism Graph
Drug Name		Trovafloxacin				Didanosine
Mechanism		Binds to polyvalent cations				Polyvalent cations
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 Didanosine due to formation of complexes caused by Trovafloxacin

Recommended Action
Management		Trovafloxacin should be administered at least 2 hours before or 2 hours after didanosine buffered tablets or pediatric oral solution, and patients should be monitored for potentially decreased antimicrobial efficacy during concomitant therapy. Didanosine buffered powder for oral solution, which uses a citrate-phosphate buffer, and the delayed-release capsules, which are not buffered, are not expected to cause this interaction.

References
1	Knupp CA, Barbhaiya RH "A multiple-dose pharmacokinetic interaction study between didanosine (videx(r)) and ciprofloxacin (cipro(r)) in male subjects seropositive for HIV but asymptomatic." Biopharm Drug Dispos 18 (1997): 65-77. [PMID: 9008270]
2	Marchbanks CR "Drug-drug interactions with fluoroquinolones." Pharmacotherapy 13 (1993): s23-8. [PMID: 8474934]
3	Polk RE "Drug-drug interactions with ciprofloxacin and other fluoroquinolones." Am J Med 87 (1989): s76-81. [PMID: 2686430]
4	Product Information. Trovan (trovafloxacin). Pfizer US Pharmaceuticals, New York, NY.
5	Sahai J, Gallicano K, Oliveras L, Khaliq S, Hawley-Foss N, Garber G "Cations in the didanosine tablet reduce ciprofloxacin bioavailability." Clin Pharmacol Ther 53 (1993): 292-7. [PMID: 8453847]
6	Teng R, Dogolo LC, Willavize SA, Friedman HL, Vincent J "Effect of Maalox and omeprazole on the bioavailability of trovafloxacin." J Antimicrob Chemother 39 Suppl B (1997): 93-7. [PMID: 9222077]
7	Damle BD, Mummaneni V, Kaul S, Knupp C "Lack of Effect of Simultaneously Administered Didanosine Encapsulated Enteric Bead Formulation (Videx EC) on Oral Absorption of Indinavir, Ketoconazole, or Ciprofloxacin." Antimicrob Agents Chemother 46 (2002): 385-91. [PMID: 11796346]