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Drug Interactions between Norpace and propafenone

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

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Interactions between your drugs

Major

disopyramide propafenone

Applies to: Norpace (disopyramide) and propafenone

GENERALLY AVOID: Coadministration of propafenone with Class IA antiarrhythmic agents may produce additive effects on the QT interval of the electrocardiogram. Theoretically, this may increase the risk of ventricular arrhythmias including torsade de pointes and sudden death. Conflicting information exists as to whether propafenone alone prolongs the QT interval. Some clinicians suggest it does, although data in the medical literature do not support a clinically significant effect of propafenone and other Class IC agents on the QT interval. Moreover, because propafenone prolongs the QRS interval in the electrocardiogram, any changes in the QT interval are difficult to interpret. Nevertheless, proarrhythmic effects including sudden death and life-threatening ventricular arrhythmias such as ventricular fibrillation, ventricular tachycardia, asystole, and torsade de pointes have been associated with its use. Since propafenone has not been extensively studied for use in conjunction with other antiarrhythmic agents or agents that prolong the QT interval, caution may be advisable. 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: Propafenone product labeling recommends that concomitant use with Class IA and III antiarrhythmic agents be avoided. In addition, these agents should be withheld for at least 5 half-lives prior to dosing with propafenone. Close monitoring of clinical response, ECG, and drug levels is recommended if concomitant use is required. 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 (6)
  1. Hii JT, Wyse DG, Gillis AM, et al. (1991) "Propafenone-induced torsade de pointes: cross-reactivity with quinidine." Pacing Clin Electrophysiol, 14, p. 1568-70
  2. Zehender M, Hohnloser S, Geibel A, et al. (1992) "Short-term and long-term treatment with propafenone: determinants of arrhythmia suppression, persistence of efficacy, arrhythmogenesis, and side effects in patients." Br Heart J, 67, p. 491-7
  3. Klein RC, Huang SK, Marcus FI, et al. (1987) "Enhanced antiarrhythmic efficacy of propafenone when used in combination with procainamide or quinidine." Am Heart J, 114, p. 551-8
  4. Buss J, Neuss H, Bilgin Y, Schlepper M (1985) "Malignant ventricular tachyarrhythmias in association with propafenone treatment." Eur Heart J, 6, p. 424-8
  5. "Product Information. Rythmol (propafenone)." Knoll Pharmaceutical Company
  6. (2011) "Product Information. Rythmol SR (propafenone)." GlaxoSmithKline

Drug and food interactions

Moderate

disopyramide food

Applies to: Norpace (disopyramide)

MONITOR: Grapefruit juice may increase the plasma concentrations of orally administered drugs that are substrates of the CYP450 3A4 isoenzyme. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit. Because grapefruit juice inhibits primarily intestinal rather than hepatic CYP450 3A4, the magnitude of interaction is greatest for those drugs that undergo significant presystemic metabolism by CYP450 3A4 (i.e., drugs with low oral bioavailability). 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. Pharmacokinetic interactions involving grapefruit juice are also subject to a high degree of interpatient variability, thus the extent to which a given patient may be affected is difficult to predict.

MANAGEMENT: Patients who regularly consume grapefruit or grapefruit juice should be monitored for adverse effects and altered plasma concentrations of drugs that undergo significant presystemic metabolism by CYP450 3A4. Grapefruit and grapefruit juice should be avoided if an interaction is suspected. Orange juice is not expected to interact with these drugs.

References (32)
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  2. Jonkman JH, Sollie FA, Sauter R, Steinijans VW (1991) "The influence of caffeine on the steady-state pharmacokinetics of theophylline." Clin Pharmacol Ther, 49, p. 248-55
  3. Bailey DG, Arnold JM, Munoz C, Spence JD (1993) "Grapefruit juice--felodipine interaction: mechanism, predictability, and effect of naringin." Clin Pharmacol Ther, 53, p. 637-42
  4. Bailey DG, Arnold JMO, Spence JD (1994) "Grapefruit juice and drugs - how significant is the interaction." Clin Pharmacokinet, 26, p. 91-8
  5. Sigusch H, Hippius M, Henschel L, Kaufmann K, Hoffmann A (1994) "Influence of grapefruit juice on the pharmacokinetics of a slow release nifedipine formulation." Pharmazie, 49, p. 522-4
  6. Bailey DG, Arnold JM, Strong HA, Munoz C, Spence JD (1993) "Effect of grapefruit juice and naringin on nisoldipine pharmacokinetics." Clin Pharmacol Ther, 54, p. 589-94
  7. Yamreudeewong W, Henann NE, Fazio A, Lower DL, Cassidy TG (1995) "Drug-food interactions in clinical practice." J Fam Pract, 40, p. 376-84
  8. (1995) "Grapefruit juice interactions with drugs." Med Lett Drugs Ther, 37, p. 73-4
  9. Hukkinen SK, Varhe A, Olkkola KT, Neuvonen PJ (1995) "Plasma concentrations of triazolam are increased by concomitant ingestion of grapefruit juice." Clin Pharmacol Ther, 58, p. 127-31
  10. 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
  11. Majeed A, Kareem A (1996) "Effect of grapefruit juice on cyclosporine pharmacokinetics." Pediatr Nephrol, 10, p. 395
  12. 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
  13. Josefsson M, Zackrisson AL, Ahlner J (1996) "Effect of grapefruit juice on the pharmacokinetics of amlodipine in healthy volunteers." Eur J Clin Pharmacol, 51, p. 189-93
  14. Kantola T, Kivisto KT, Neuvonen PJ (1998) "Grapefruit juice greatly increases serum concentrations of lovastatin and lovastatin acid." Clin Pharmacol Ther, 63, p. 397-402
  15. Ozdemir M, Aktan Y, Boydag BS, Cingi MI, Musmul A (1998) "Interaction between grapefruit juice and diazepam in humans." Eur J Drug Metab Pharmacokinet, 23, p. 55-9
  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, Kreeft JH, Munoz C, Freeman DJ, Bend JR (1998) "Grapefruit juice felodipine interaction: Effect of naringin and 6',7'-dihydroxybergamottin in humans." Clin Pharmacol Ther, 64, p. 248-56
  18. Garg SK, Kumar N, Bhargava VK, Prabhakar SK (1998) "Effect of grapefruit juice on carbamazepine bioavailability in patients with epilepsy." Clin Pharmacol Ther, 64, p. 286-8
  19. Lilja JJ, Kivisto KT, Neuvonen PJ (1998) "Grapefruit juice-simvastatin interaction: Effect on serum concentrations of simvastatin, simvastatin acid, and HMG-CoA reductase inhibitors." Clin Pharmacol Ther, 64, p. 477-83
  20. Fuhr U, Maier-Bruggemann A, Blume H, et al. (1998) "Grapefruit juice increases oral nimodipine bioavailability." Int J Clin Pharmacol Ther, 36, p. 126-32
  21. Lilja JJ, Kivisto KT, Neuvonen PJ (1999) "Grapefruit juice increases serum concentrations of atorvastatin and has no effect on pravastatin." Clin Pharmacol Ther, 66, p. 118-27
  22. Eagling VA, Profit L, Back DJ (1999) "Inhibition of the CYP3A4-mediated metabolism and P-glycoprotein-mediated transport of the HIV-I protease inhibitor saquinavir by grapefruit juice components." Br J Clin Pharmacol, 48, p. 543-52
  23. Damkier P, Hansen LL, Brosen K (1999) "Effect of diclofenac, disulfiram, itraconazole, grapefruit juice and erythromycin on the pharmacokinetics of quinidine." Br J Clin Pharmacol, 48, p. 829-38
  24. Lee AJ, Chan WK, Harralson AF, Buffum J, Bui BCC (1999) "The effects of grapefruit juice on sertraline metabolism: An in vitro and in vivo study." Clin Ther, 21, p. 1890-9
  25. Dresser GK, Spence JD, Bailey DG (2000) "Pharmacokinetic-pharmacodynamic consequences and clinical relevance of cytochrome P450 3A4 inhibition." Clin Pharmacokinet, 38, p. 41-57
  26. Gunston GD, Mehta U (2000) "Potentially serious drug interactions with grapefruit juice." S Afr Med J, 90, p. 41
  27. Takanaga H, Ohnishi A, Maatsuo H, et al. (2000) "Pharmacokinetic analysis of felodipine-grapefruit juice interaction based on an irreversible enzyme inhibition model." Br J Clin Pharmacol, 49, p. 49-58
  28. Libersa CC, Brique SA, Motte KB, et al. (2000) "Dramatic inhibition of amiodarone metabolism induced by grapefruit juice." Br J Clin Pharmacol, 49, p. 373-8
  29. 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
  30. Zaidenstein R, Soback S, Gips M, Avni B, Dishi V, Weissgarten Y, Golik A, Scapa E (2001) "Effect of grapefruit juice on the pharmacokinetics of losartan and its active metabolite E3174 in healthy volunteers." Ther Drug Monit, 23, p. 369-73
  31. Sato J, Nakata H, Owada E, Kikuta T, Umetsu M, Ito K (1993) "Influence of usual intake of dietary caffeine on single-dose kinetics of theophylline in healthy human subjects." Eur J Clin Pharmacol, 44, p. 295-8
  32. Flanagan D (2005) "Understanding the grapefruit-drug interaction." Gen Dent, 53, 282-5; quiz 286
Moderate

propafenone food

Applies to: 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
Minor

disopyramide food

Applies to: Norpace (disopyramide)

Ethanol significantly increases the renal elimination of disopyramide, apparently by inducing diuresis (inhibition of antidiuretic hormone). Limited data show that ethanol does not, however, significantly affect the elimination half-life or total plasma clearance of disopyramide. No special precautions appear to be necessary.

References (1)
  1. Olsen H, Bredesen JE, Lunde PK (1983) "Effect of ethanol intake on disopyramide elimination by healthy volunteers." Eur J Clin Pharmacol, 25, p. 103-5

Therapeutic duplication warnings

Therapeutic duplication is the use of more than one medicine from the same drug category or therapeutic class to treat the same condition. This can be intentional in cases where drugs with similar actions are used together for demonstrated therapeutic benefit. It can also be unintentional in cases where a patient has been treated by more than one doctor, or had prescriptions filled at more than one pharmacy, and can have potentially adverse consequences.

Duplication

Antiarrhythmics

Therapeutic duplication

The recommended maximum number of medicines in the 'antiarrhythmics' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'antiarrhythmics' category:

  • Norpace (disopyramide)
  • propafenone

Note: In certain circumstances, the benefits of taking this combination of drugs may outweigh any risks. Always consult your healthcare provider before making changes to your medications or dosage.

Duplication

Group i antiarrhythmics

Therapeutic duplication

The recommended maximum number of medicines in the 'group I antiarrhythmics' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'group I antiarrhythmics' category:

  • Norpace (disopyramide)
  • propafenone

Note: In certain circumstances, the benefits of taking this combination of drugs may outweigh any risks. Always consult your healthcare provider before making changes to your medications or dosage.

See also

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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.

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