Drug Interactions between Quinidex Extentabs and temsirolimus
This report displays the potential drug interactions for the following 2 drugs:
- Quinidex Extentabs (quinidine)
- temsirolimus
Interactions between your drugs
quiNIDine temsirolimus
Applies to: Quinidex Extentabs (quinidine) and temsirolimus
MONITOR: Coadministration of sirolimus or tacrolimus with other drugs that are also metabolized by CYP450 3A4 may result in elevated plasma concentrations of the macrolide immunosuppressant and/or the coadministered drug(s). The mechanism is decreased drug clearance due to competitive inhibition of CYP450 3A4 activity. Although clinical data are lacking, the possibility of prolonged and/or increased pharmacologic effects of the drugs should be considered.
MANAGEMENT: Pharmacologic responses and/or plasma drug levels should be monitored more closely whenever a macrolide immunosuppressant or another substrate of CYP450 3A4 is added to or withdrawn from therapy, and the dosage(s) adjusted as necessary.
References (2)
- (2001) "Product Information. Prograf (tacrolimus)." Fujisawa
- (2001) "Product Information. Rapamune (sirolimus)." Wyeth-Ayerst Laboratories
Drug and food interactions
quiNIDine food
Applies to: Quinidex Extentabs (quinidine)
GENERALLY AVOID: In a small, randomized, crossover study, the administration of quinidine with grapefruit juice (compared to water) to healthy volunteers significantly prolonged the time to reach peak plasma quinidine concentrations and decreased the plasma concentrations of its major metabolite, 3-hydroxyquinidine. These changes were associated pharmacodynamically with both a delay and a reduction in the maximal effect on QTc interval. The proposed mechanism is delay of gastric emptying as well as inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall induced by certain compounds present in grapefruits.
MANAGEMENT: Given the drug's narrow therapeutic index, patients receiving quinidine therapy should avoid the consumption of grapefruits and grapefruit juice to prevent any undue fluctuations in plasma drug levels.
References (4)
- Ace LN, Jaffe JM, Kunka RL (1983) "Effect of food and an antacid on quinidine bioavailability." Biopharm Drug Dispos, 4, p. 183-90
- Min DI, Ku YM, Geraets DR, Lee HC (1996) "Effect of grapefruit juice on the pharmacokinetics and pharmacodynamics of quinidine in healthy volunteers." J Clin Pharmacol, 36, p. 469-76
- Ha HR, Chen J, Leuenberger PM, Freiburghaus AU, Follah F (1995) "In vitro inhibition of midazolam and quinidine metabolism by flavonoids." Eur J Clin Pharmacol, 48, p. 367-71
- 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
temsirolimus food
Applies to: temsirolimus
GENERALLY AVOID: Coadministration of temsirolimus with grapefruit juice may increase the plasma concentrations of sirolimus, a major active metabolite of temsirolimus and known substrate of CYP450 3A4. The proposed mechanism is inhibition of CYP450 3A4-mediated metabolism by certain compounds present in grapefruits.
MANAGEMENT: Patients treated with temsirolimus should preferably avoid the consumption of grapefruit or grapefruit juice.
References (1)
- (2007) "Product Information. Torisel (temsirolimus)." Wyeth-Ayerst Laboratories
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.
See also
Drug Interaction Classification
Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
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. | |
No interaction information available. |
Further information
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