Drug General Information (ID: DDISN1DW4L)
Drug Name			Ondansetron		Drug Info		Ofloxacin		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Antiemetics				Antibiotics
Structure

Mechanism of Ondansetron-Ofloxacin Interaction (Severity Level: Moderate)
Increased risk of prolong QT interval Click to Show/Hide Mechanism Graph
Drug Name		Ondansetron				Ofloxacin
Mechanism		Prolong QT interval				Prolong QT interval
Key Mechanism Factor 1
		Factor Name		QT interval
		Factor Description		Long QT syndrome is a heart signaling disorder that can cause a fast, chaotic heartbeat (arrhythmia). Many people may not exhibit symptoms, and usually the condition is detected during routine medical tests. In others, the most common symptoms include: sudden fainting, palpitations, dizziness, seizures, sudden death.
Mechanism Description		Increased risk of prolong QT interval by the combination of Ondansetron and Ofloxacin

Recommended Action
Management		Although the risk of a serious interaction is probably low, caution is recommended if levofloxacin, norfloxacin, or ofloxacin is used in combination with other drugs that can prolong the QT interval. Since the magnitude of QTc prolongation increases with increasing plasma concentrations of the quinolone, recommended dosages and intravenous infusion rates should not be exceeded. Patients should be advised to seek prompt medical attention if they experience symptoms that could indicate the occurrence of torsade de pointes such as dizziness, lightheadedness, fainting, palpitation, irregular heart rhythm, shortness of breath, or syncope.

References
1	Ball P "Quinolone-induced QT interval prolongation: a not-so-unexpected class effect." J Antimicrob Chemother 45 (2000): 557-9. [PMID: 10797074]
2	Canadian Pharmacists Association.
3	Cerner Multum, Inc. "Australian Product Information.".
4	Cerner Multum, Inc. "UK Summary of Product Characteristics.".
5	Falagas ME, Rafailidis PI, Rosmarakis ES "Arrhythmias associated with fluoroquinolone therapy." Int J Antimicrob Agents 29 (2007): 374-9. [PMID: 17241772]
6	Frothingham R "Rates of torsades de pointes associated with ciprofloxacin, ofloxacin, levofloxacin, gatifloxacin, and moxifloxacin." Pharmacotherapy 21 (2001): 1468-72. [PMID: 11765299]
7	Iannini PB "Cardiotoxicity of macrolides, ketolides and fluoroquinolones that prolong the QTc interval." Expert Opin Drug Saf 1 (2002): 121-8. [PMID: 12904146]
8	Iannini PB, Doddamani S, Byazrova E, Curciumaru I, Kramer H "Risk of torsades de pointes with non-cardiac drugs. Prolongation of QT interval is probably a class effect of fluoroquinolones." Br Med J 322 (2001): 46-7. [PMID: 11141163]
9	Kahn JB "Latest industry information on the safety profile of levofloxacin in the US." Chemotherapy 47 Suppl 3 (2001): 32-7. [PMID: 11549787]
10	Kang J, Wang L, Chen XL, Triggle DJ, Rampe D "Interactions of a series of fluoroquinolone antibacterial drugs with the human cardiac K+ channel HERG." Mol Pharmacol 59 (2001): 122-6. [PMID: 11125032]
11	Katritsis D, Camm AJ "Quinolones: cardioprotective or cardiotoxic." Pacing Clin Electrophysiol 26 (2003): 2317-20. [PMID: 14675020]
12	Makaryus AN, Byrns K, Makaryus MN, Natarajan U, Singer C, Goldner B "Effect of ciprofloxacin and levofloxacin on the QT interval: is this a significant "clinical" event?" South Med J 99 (2006): 52-6. [PMID: 16466123]
13	Noel GJ, Natarajan J, Chien S, Hunt TL, Goodman DB, Abels R "Effects of three fluoroquinolones on QT interval in healthy adults after single doses." Clin Pharmacol Ther 73 (2003): 292-303. [PMID: 12709719]
14	Nykamp DL, Blackmon CL, Schmidt PE, Roberson AG "QTc prolongation associated with combination therapy of levofloxacin, imipramine, and fluoxetine." Ann Pharmacother 39 (2005): 543-6. [PMID: 15687478]
15	Oliphant CM, Green GM "Quinolones: a comprehensive review." Am Fam Physician 65 (2002): 455-64. [PMID: 11858629]
16	Owens RC "QT Prolongation with Antimicrobial Agents : Understanding the Significance." Drugs 64 (2004): 1091-124. [PMID: 15139788]
17	Owens RC "Risk assessment for antimicrobial agent-induced QTc interval prolongation and torsades de pointes." Pharmacotherapy 21 (2001): 301-19. [PMID: 11253855]
18	Owens RC Jr, Ambrose PG "Torsades de pointes associated with fluoroquinolones." Pharmacotherapy 22 (2002): 663-8 discussion 668-72. [PMID: 12013370]
19	Product Information. Floxin (ofloxacin). Ortho Pharmaceutical Corporation, Raritan, NJ.
20	Product Information. Levaquin (levofloxacin). Ortho Pharmaceutical Corporation, Raritan, NJ.
21	Samaha FF "QTC interval prolongation and polymorphic ventricular tachycardia in association with levofloxacin." Am J Med 107 (1999): 528-9. [PMID: 10569314]
22	Stahlmann R "Clinical toxicological aspects of fluoroquinolones." Toxicol Lett 127 (2002): 269-77. [PMID: 12052667]
23	Thomas M, Maconochie JG, Fletcher E "The dilemma of the prolonged QT interval in early drug studies." Br J Clin Pharmacol 41 (1996): 77-81. [PMID: 8838432]