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Drug Interactions between levofloxacin and terfenadine

This report displays the potential drug interactions for the following 2 drugs:

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Interactions between your drugs

Moderate

terfenadine levoFLOXacin

Applies to: terfenadine and levofloxacin

MONITOR: Certain quinolones, including levofloxacin, norfloxacin, and ofloxacin, may cause dose-related prolongation of the QT interval in some patients. Theoretically, coadministration with other agents that can prolong the QT interval may result in additive effects and increased risk of ventricular arrhythmias including torsade de pointes and sudden death. During postmarketing surveillance, rare cases of torsade de pointes and ventricular tachycardia have been reported in patients taking levofloxacin, norfloxacin, and ofloxacin. The levofloxacin cases primarily involved patients with underlying medical conditions or taking concomitant medications that may have been contributory. In general, the risk of an individual agent or a combination of agents causing ventricular arrhythmia in association with QT prolongation is largely unpredictable but may be increased by certain underlying risk factors such as congenital long QT syndrome, cardiac disease, and electrolyte disturbances (e.g., hypokalemia, hypomagnesemia). In addition, the extent of drug-induced QT prolongation is dependent on the particular drug(s) involved and dosage(s) of the drug(s).

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

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Drug and food interactions

Major

terfenadine food

Applies to: terfenadine

CONTRAINDICATED: The consumption of grapefruit juice has been associated with significantly increased plasma concentrations of terfenadine. The mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall induced by certain compounds present in grapefruits. Terfenadine in high serum levels has been associated with prolongation of the QT interval and development of torsade de pointes, a potentially fatal ventricular arrhythmia.

MANAGEMENT: Due to the risk of cardiotoxicity, patients receiving the drug should be advised to avoid consumption of grapefruit products. Loratadine, cetirizine, and fexofenadine may be safer alternatives in patients who may have trouble adhering to the dietary restriction.

References

  1. Honig PK, Woosley RL, Zamani K, Conner DP, Cantilena LR Jr (1992) "Changes in the pharmacokinetics and electrocardiographic pharmacodynamics of terfenadine with concomitant administration of erythromycin." Clin Pharmacol Ther, 52, p. 231-8
  2. Zimmermann M, Duruz H, Guinand O, et al. (1992) "Torsades de Pointes after treatment with terfenadine and ketoconazole." Eur Heart J, 13, p. 1002-3
  3. Mathews DR, McNutt B, Okerholm R, et al. (1991) "Torsades de pointes occurring in association with terfenadine use." JAMA, 266, p. 2375-6
  4. Monahan BP, Ferguson CL, Killeavy ES, et al. (1990) "Torsades de pointes occurring in association with terfenadine use." JAMA, 264, p. 2788-90
  5. Honig PK, Wortham DC, Zamani K, et al. (1993) "Terfenadine-ketoconazole interaction: pharmacokinetic and electrocardiographic consequences." JAMA, 269, p. 1513-8
  6. Pohjola-Sintonen S, Viitasalo M, Toivonene L, Neuvonen P (1993) "Torsades de pointes after terfenadine-itraconazole interaction." BMJ, 306, p. 186
  7. Cortese LM, Bjornson DC (1992) "Potential interaction between terfenadine and macrolide antibiotics." Clin Pharm, 11, p. 675
  8. Paris DG, Parente TF, Bruschetta HR, Guzman E, Niarchos AP (1994) "Torsades-de-pointes induced by erythromycin and terfenadine." Am J Emerg Med, 12, p. 636-8
  9. Zechnich AD, Haxby DG (1996) "Drug interactions associated with terfenadine and related nonsedating antihistamines." West J Med, 164, p. 68-9
  10. Honig PK, Wortham DC, Lazarev A, Cantilena LR (1996) "Grapefruit juice alters the systemic bioavailability and cardiac repolarization of terfenadine in poor metabolizers of terfenadine." J Clin Pharmacol, 36, p. 345-51
  11. Woosley RL (1996) "Cardiac actions of antihistamines." Annu Rev Pharmacol Toxicol, 36, p. 233-52
  12. Benton RE, Honig PK, Zamani K, Cantilena LR, Woosley RL (1996) "Grapefruit juice alters terfenadine pharmacokinetics resulting in prolongation of repolarization on the electrocardiogram." Clin Pharmacol Ther, 59, p. 383-8
  13. Hsieh MH, Chen SA, Chiang CE, et al. (1996) "Drug-induced torsades de pointes in one patient with congenital long QT syndrome." Int J Cardiol, 54, p. 85-8
  14. Clifford CP, Adams DA, Murray S, Taylor GW, Wilkins MR, Boobis AR, Davies DS (1996) "Pharmacokinetic and cardiac effects of terfenadine after inhibition of its metabolism by grapefruit juice." Br J Clin Pharmacol, 42, p662
  15. Rau SE, Bend JR, Arnold JMO, Tran LT, Spence JD, Bailey DG (1997) "Grapefruit juice terfenadine single-dose interaction: Magnitude, mechanism, and relevance." Clin Pharmacol Ther, 61, p. 401-9
  16. Bailey DG, Malcolm J, Arnold O, Spence JD (1998) "Grapefruit juice-drug interactions." Br J Clin Pharmacol, 46, p. 101-10
  17. Bailey DG, Dresser GR, Kreeft JH, Munoz C, Freeman DJ, Bend JR (2000) "Grapefruit-felodipine interaction: Effect of unprocessed fruit and probable active ingredients." Clin Pharmacol Ther, 68, p. 468-77
View all 17 references

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Moderate

levoFLOXacin food

Applies to: levofloxacin

ADJUST DOSING INTERVAL: Food may reduce the oral absorption and bioavailability of levofloxacin. According to the drug product labeling, administration of levofloxacin 500 mg with food prolonged the time to peak concentration by 1 hour and decreased the Cmax decreased by 25% following administration of the oral solution and by 14% following administration of the oral tablet.

MANAGEMENT: To ensure maximal and consistent oral absorption, levofloxacin oral solution should be taken at least one hour before or two hours after meals. For administration of the oral solution with continuous enteral nutrition, some experts recommend that the tube feeding should be interrupted for one hour before and two hours after the dose of levofloxacin. The oral tablets may be taken without regard to food.

References

  1. Wohlt PD, Zheng L, Gunderson S, Balzar SA, Johnson BD, Fish JT (2009) "Recommendations for the use of medications with continuous enteral nutrition." Am J Health Syst Pharm, 66, p. 1438-67

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Therapeutic duplication warnings

No warnings were found for your selected drugs.

Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.


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Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No interaction information available.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.