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Drug Interactions between eslicarbazepine and Rythmol SR

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

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Interactions between your drugs

Moderate

propafenone eslicarbazepine

Applies to: Rythmol SR (propafenone) and eslicarbazepine

MONITOR: There is clinical evidence that eslicarbazepine acetate can prolong the PR interval of the electrocardiogram (ECG) in some patients. Theoretically, coadministration with other agents that prolong the PR interval (e.g., beta blockers, calcium channel blockers, atazanavir, lopinavir, digoxin, lacosamide, mefloquine) may result in additive effects and increased risk of conduction disturbances and atrioventricular (AV) block. In phase III adult adjunctive epilepsy studies in patients who received eslicarbazepine acetate 400 mg, 800 mg, or 1200 mg per day, mean increases in the PR interval at the end of 12 weeks of maintenance treatment were 2.4 msec, 1.3 msec, and 2.6 msec, respectively, compared to 0.6 msec in the placebo group. PR interval values greater than 200 msec at study end that were not present at baseline were observed in 0.8% and 0.2% of patients treated with eslicarbazepine acetate and placebo, respectively. In a clinical pharmacology ECG trial of healthy subjects who received either the maximum recommended daily dose of eslicarbazepine acetate (1200 mg), two times the maximum recommended daily dose of eslicarbazepine acetate (2400 mg) or placebo for five days, the maximum mean placebo-adjusted increase in the PR interval on day 5 was 4.4 msec at 5 hours post-dose for the 1200 mg group, and 8.2 msec at 3 hours post-dose for the 2400 mg group. Excessive PR interval prolongation can result in AV block. Cases of AV block have been reported in post-marketing experience.

MANAGEMENT: Caution is advised if eslicarbazepine is used concomitantly with other agents that prolong the PR interval, especially in the elderly and patients with known conduction problems (e.g., marked first-degree AV block; second-degree or higher AV block; sick sinus syndrome without pacemaker), or a history of syncope, arrhythmia or severe cardiac disease such as myocardial ischemia or heart failure. Patients should be advised to notify their doctor if they experience dizziness, lightheadedness, fainting, or irregular heartbeat.

References (4)
  1. Cerner Multum, Inc. "UK Summary of Product Characteristics."
  2. Cerner Multum, Inc. "Australian Product Information."
  3. (2013) "Product Information. Aptiom (eslicarbazepine)." Sunovion Pharmaceuticals Inc
  4. Cerner Multum, Inc. (2015) "Canadian Product Information."

Drug and food interactions

Moderate

propafenone food

Applies to: Rythmol SR (propafenone)

GENERALLY AVOID: Grapefruit juice may increase the plasma concentrations of propafenone. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit. Inhibition of hepatic CYP450 3A4 may also contribute. In over 90% of patients, propafenone is rapidly and extensively converted to 2 active metabolites: 5-hydroxypropafenone via CYP450 2D6 and N-depropylpropafenone (norpropafenone) via CYP450 3A4 and 1A2. In less than 10% of patients (approximately 6% of Caucasians in the U.S. population), however, metabolism of propafenone is slower because the 5-hydroxy metabolite is not formed, or minimally formed, due to a genetic deficiency in CYP450 2D6. In these poor metabolizers of CYP450 2D6, clearance of propafenone via the CYP450 3A4 and 1A2 metabolic pathways becomes more important, and inhibition of these pathways may substantially increase systemic exposure to propafenone. Likewise, patients taking concomitant inhibitors of CYP450 2D6 and 3A4 may experience similar pharmacokinetic effects. In general, the effect of grapefruit juice is concentration-, dose- and preparation-dependent, and can vary widely among brands. Certain preparations of grapefruit juice (e.g., high dose, double strength) have sometimes demonstrated potent inhibition of CYP450 3A4, while other preparations (e.g., low dose, single strength) have typically demonstrated moderate inhibition. Increased systemic exposure to propafenone may result in proarrhythmic events and exaggerated beta-adrenergic blocking activity.

MANAGEMENT: It may be advisable for patients to avoid the consumption of grapefruit, grapefruit juice, or supplements that contain grapefruit during treatment with propafenone.

References (4)
  1. Botsch S, Gautier JC, Beaune P, Eichelbaum M, Kroemer HK (1993) "Identification and characterization of the cytochrome P450 enzymes involved in N-dealkylation of propafenone: molecular base for interaction potential and variable disposition of active metabolites." Mol Pharmacol, 43, p. 120-6
  2. (2011) "Product Information. Rythmol SR (propafenone)." GlaxoSmithKline
  3. (2023) "Product Information. Apo-Propafenone (propafenone)." Apotex Incorporated
  4. (2022) "Product Information. Propafenone (propafenone)." Accord-UK Ltd

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.