Drug Interactions between dronedarone and pimozide
This report displays the potential drug interactions for the following 2 drugs:
- dronedarone
- pimozide
Interactions between your drugs
pimozide dronedarone
Applies to: pimozide and dronedarone
CONTRAINDICATED: Dronedarone may cause dose-related prolongation of the QT interval. 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. In healthy subjects given repeated oral doses, dronedarone induced a QTc prolongation of about 10 ms at 400 mg twice daily and up to 25 ms at 1600 mg twice daily. In clinical trials using a dosage of 400 mg twice daily, premature discontinuation of therapy due to QT prolongation occurred in 1.5% of dronedarone patients versus 0.5% of placebo patients. 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: Coadministration of dronedarone with other drugs that can prolong the QT interval is considered contraindicated.
References (4)
- Cerner Multum, Inc. "UK Summary of Product Characteristics."
- Canadian Pharmacists Association (2006) e-CPS. http://www.pharmacists.ca/function/Subscriptions/ecps.cfm?link=eCPS_quikLink
- Cerner Multum, Inc. "Australian Product Information."
- (2009) "Product Information. Multaq (dronedarone)." sanofi-aventis
Drug and food interactions
pimozide food
Applies to: pimozide
GENERALLY AVOID: Theoretically, the coadministration with grapefruit juice may increase the plasma concentrations of pimozide. The mechanism is decreased clearance of pimozide due to inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits. The use of pimozide alone has been associated with dose-dependent prolongation of the QT interval. Although clinical data are lacking, this interaction may result in potentiation of the proarrhythmic effect of pimozide and consequently an increased risk of ventricular arrhythmias such as ventricular tachycardia and torsade de pointes. In addition, alcohol may potentiate some of the pharmacologic effects of pimozide. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.
MANAGEMENT: The manufacturer recommends avoiding grapefruit juice (and probably grapefruits) during therapy with pimozide. Patients should also be advised to avoid or limit consumption of alcohol.
References (2)
- "Product Information. Orap (pimozide)." Gate Pharmaceuticals
- Dresser GK, Spence JD, Bailey DG (2000) "Pharmacokinetic-pharmacodynamic consequences and clinical relevance of cytochrome P450 3A4 inhibition." Clin Pharmacokinet, 38, p. 41-57
dronedarone food
Applies to: dronedarone
GENERALLY AVOID: Grapefruit juice may increase the plasma concentrations of dronedarone. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits. According to the product labeling, administration with grapefruit juice resulted in a 2.5-fold increase in dronedarone peak plasma concentration and a 3-fold increase in systemic exposure. Because dronedarone is associated with concentration-dependent prolongation of the QT interval, increased levels may potentiate the risk of ventricular arrhythmias such as torsade de pointes and sudden death.
ADJUST DOSING INTERVAL: Food increases the oral bioavailability of dronedarone. The mechanism of interaction is unknown. According to the product labeling, the absolute bioavailability of dronedarone increases from about 4% when administered in the fasted state to approximately 15% when administered with a high-fat meal.
MANAGEMENT: Patients treated with dronedarone should avoid consumption of grapefruit, grapefruit juice, and any supplement containing grapefruit extract. Dronedarone should be taken twice daily with the morning and evening meals.
References (1)
- (2009) "Product Information. Multaq (dronedarone)." sanofi-aventis
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
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
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