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Mar PL, Horbal P, Chung MK, Dukes JW, Ezekowitz M, Lakkireddy D, Lip GYH, Miletello M, Noseworthy PA, Reiffel JA, Tisdale JE, Olshansky B, Gopinathannair R. Drug Interactions Affecting Antiarrhythmic Drug Use. Circ Arrhythm Electrophysiol 2022; 15:e007955. [PMID: 35491871 DOI: 10.1161/circep.121.007955] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Antiarrhythmic drugs (AAD) play an important role in the management of arrhythmias. Drug interactions involving AAD are common in clinical practice. As AADs have a narrow therapeutic window, both pharmacokinetic as well as pharmacodynamic interactions involving AAD can result in serious adverse drug reactions ranging from arrhythmia recurrence, failure of device-based therapy, and heart failure, to death. Pharmacokinetic drug interactions frequently involve the inhibition of key metabolic pathways, resulting in accumulation of a substrate drug. Additionally, over the past 2 decades, the P-gp (permeability glycoprotein) has been increasingly cited as a significant source of drug interactions. Pharmacodynamic drug interactions involving AADs commonly involve additive QT prolongation. Amiodarone, quinidine, and dofetilide are AADs with numerous and clinically significant drug interactions. Recent studies have also demonstrated increased morbidity and mortality with the use of digoxin and other AAD which interact with P-gp. QT prolongation is an important pharmacodynamic interaction involving mainly Vaughan-Williams class III AAD as many commonly used drug classes, such as macrolide antibiotics, fluoroquinolone antibiotics, antipsychotics, and antiemetics prolong the QT interval. Whenever possible, serious drug-drug interactions involving AAD should be avoided. If unavoidable, patients will require closer monitoring and the concomitant use of interacting agents should be minimized. Increasing awareness of drug interactions among clinicians will significantly improve patient safety for patients with arrhythmias.
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Affiliation(s)
- Philip L Mar
- Department of Medicine, Division of Cardiology, St. Louis University, St. Louis, MO (P.L.M., P.H.)
| | - Piotr Horbal
- Department of Medicine, Division of Cardiology, St. Louis University, St. Louis, MO (P.L.M., P.H.)
| | - Mina K Chung
- Department of Cardiovascular Medicine, Heart, Vascular & Thoracic Institute (M.K.C.), Cleveland Clinic, OH
| | | | - Michael Ezekowitz
- Lankenau Heart Institute, Bryn Mawr Hospital & Sidney Kimmel Medical College (M.E.)
| | | | - Gregory Y H Lip
- Liverpool Centre for Cardiovascular Science, University of Liverpool & Liverpool Heart & Chest Hospital, Liverpool, United Kingdom (G.Y.H.L.).,Department of Clinical Medicine, Aalborg, Denmark (G.Y.H.L.)
| | | | - Peter A Noseworthy
- Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN (P.A.N.)
| | - James A Reiffel
- Division of Cardiology, Department of Medicine, Columbia University, New York, NY (J.A.R.)
| | - James E Tisdale
- College of Pharmacy, Purdue University (J.E.T.).,School of Medicine, Indiana University, Indianapolis (J.E.T.)
| | - Brian Olshansky
- Division of Cardiology, Department of Medicine, University of Iowa, Iowa City (B.O.)
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Gavronski M, Hartikainen S, Zharkovsky A. Analysis of potential interactions between warfarin and prescriptions in Estonian outpatients aged 50 years or more. Pharm Pract (Granada) 2012; 10:9-16. [PMID: 24155811 PMCID: PMC3798168 DOI: 10.4321/s1886-36552012000100003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Accepted: 01/17/2012] [Indexed: 12/05/2022] Open
Abstract
In Estonia, warfarin is widely prescribed by general practitioners to prevent
and treat thromboembolic diseases. To date, there has been no systematic
analysis of the potential risk of warfarin interactions with other drugs in
the outpatient population. Objective The aim of the study was to analyze the incidence of potential interactions
in prescription schemes in Estonia in a cohort of outpatients receiving
warfarin treatment. Methods The retrospective study population included 203,646 outpatients aged 50 years
or older of whom 7,175 received warfarin therapy. Patients who had used at
least one prescription drug for a minimum period of 7 days concomitantly
with warfarin were analyzed. Potential drug interactions were analyzed using
Epocrates online, Stockley's Drug Interactions and domestic drug
interaction databases. Results The average number of drugs used concomitantly with warfarin was 4.8 (SD=1.9)
(males: 4.7 SD=2.0, females: 4.9 SD=2.0). No potential interactions in
treatment regimens were found in 38% of patients, one potential interaction
was observed in 29% and two or more potential interactions were observed in
33% of patients. The mean number of all potential interactions was 1.2 per
patient and about the same in men and women. Potential interactions were
associated with the number of drugs. Warfarin-related interactions were
detected in 57% of patients, and the number of interactions related to
warfarin per patient varied from 1 to 5. Most frequent were use of warfarin
with NSAIDs (14%), followed by simvastatin (9%) and amiodarone (7%). Conclusions This study shows that 57% of outpatients in Estonia receiving warfarin have
drugs potentially interacting with warfarin in their treatment schemes. Most
interactions (14%) with warfarin are associated with the prescription of
NSAIDs.
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Affiliation(s)
- Maia Gavronski
- School of Pharmacy, University of Eastern Finland . Kuopio ( Finland )
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3
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Bungard TJ, Yakiwchuk E, Foisy M, Brocklebank C. Drug Interactions Involving Warfarin: Practice Tool and Practical Management Tips. Can Pharm J (Ott) 2011. [DOI: 10.3821/1913-701x-144.1.21] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Tammy J. Bungard
- From the Anticoagulation Management Service and Division of Cardiology, Department of Medicine, University of Alberta (Bungard), Edmonton, Alberta; College of Pharmacy and Nutrition, University of Saskatchewan (Yakiwchuk [student]), Saskatoon, Saskatchewan; Northern Alberta HIV Program, Alberta Health Services (Foisy), Edmonton, Alberta; Anticoagulation Program, Alberta Health Services (Brockle-bank), Calgary, Alberta. Contact
| | - Erin Yakiwchuk
- From the Anticoagulation Management Service and Division of Cardiology, Department of Medicine, University of Alberta (Bungard), Edmonton, Alberta; College of Pharmacy and Nutrition, University of Saskatchewan (Yakiwchuk [student]), Saskatoon, Saskatchewan; Northern Alberta HIV Program, Alberta Health Services (Foisy), Edmonton, Alberta; Anticoagulation Program, Alberta Health Services (Brockle-bank), Calgary, Alberta. Contact
| | - Michelle Foisy
- From the Anticoagulation Management Service and Division of Cardiology, Department of Medicine, University of Alberta (Bungard), Edmonton, Alberta; College of Pharmacy and Nutrition, University of Saskatchewan (Yakiwchuk [student]), Saskatoon, Saskatchewan; Northern Alberta HIV Program, Alberta Health Services (Foisy), Edmonton, Alberta; Anticoagulation Program, Alberta Health Services (Brockle-bank), Calgary, Alberta. Contact
| | - Cynthia Brocklebank
- From the Anticoagulation Management Service and Division of Cardiology, Department of Medicine, University of Alberta (Bungard), Edmonton, Alberta; College of Pharmacy and Nutrition, University of Saskatchewan (Yakiwchuk [student]), Saskatoon, Saskatchewan; Northern Alberta HIV Program, Alberta Health Services (Foisy), Edmonton, Alberta; Anticoagulation Program, Alberta Health Services (Brockle-bank), Calgary, Alberta. Contact
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Abstract
Adverse drug reactions (ADRs) occur frequently in modern medical practice, increasing morbidity and mortality and inflating the cost of care. Patients with cardiovascular disease are particularly vulnerable to ADRs due to their advanced age, polypharmacy, and the influence of heart disease on drug metabolism. The ADR potential for a particular cardiovascular drug varies with the individual, the disease being treated, and the extent of exposure to other drugs. Knowledge of this complex interplay between patient, drug, and disease is a critical component of safe and effective cardiovascular disease management. The majority of significant ADRs involving cardiovascular drugs are predictable and therefore preventable. Better patient education, avoidance of polypharmacy, and clear communication between physicians, pharmacists, and patients, particularly during the transition between the inpatient to outpatient settings, can substantially reduce ADR risk.
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Unal S, Bayrakci B, Yasar U, Karagoz T. Successful treatment of propafenone, digoxin and warfarin overdosage with plasma exchange therapy and rifampicin. Clin Drug Investig 2007; 27:505-8. [PMID: 17563131 DOI: 10.2165/00044011-200727070-00008] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We report here the successful treatment of a 16-year-old female who ingested 20 tablets of digoxin each containing 0.25 mg (total dose ingested equivalent to 0.1 mg/kg), 32 tablets of warfarin each containing 5mg (equivalent to 3.2 mg/kg), and approximately 15 tablets of propafenone each containing 300 mg (equivalent to 90 mg/kg). The patient developed hypotension and sinus bradycardia necessitating external cardiac pacing 17 hours after drug ingestion. In addition to gastric lavage, activated charcoal, blood alkalinisation, administration of vitamin K and temporary cardiac pacing, the authors performed plasma exchange for drug removal and administered rifampicin in order to increase the metabolism of digoxin, propafenone and warfarin. The patient was discharged without any sequelae. Plasma exchange may be lifesaving in drug ingestions where there is a low volume of distribution and high plasma protein binding. Rifampicin, an inducer of cytochrome p450, may be used in intoxications for elimination of drugs with inactive metabolites.
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Affiliation(s)
- Sule Unal
- Department of Pediatrics, Division of Pediatric Hematology, Hacettepe University, Faculty of Medicine, Ankara, Turkey.
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6
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DiMarco JP, Flaker G, Waldo AL, Corley SD, Greene HL, Safford RE, Rosenfeld LE, Mitrani G, Nemeth M. Factors affecting bleeding risk during anticoagulant therapy in patients with atrial fibrillation: observations from the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) study. Am Heart J 2005; 149:650-6. [PMID: 15990748 DOI: 10.1016/j.ahj.2004.11.015] [Citation(s) in RCA: 160] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Stroke and systemic thromboembolism are serious problems for patients with atrial fibrillation (AF), but their incidence can be substantially reduced by appropriate anticoagulation. Bleeding is the major complication of anticoagulant treatment, and the relative risks for bleeding vs stroke must be considered when starting anticoagulation. METHODS The AFFIRM trial included patients with AF and at least one risk factor for stroke, randomly assigning them to either a rate-control or rhythm-control strategy. All patients were initially treated with warfarin. The incidence of protocol-defined major and minor bleeding was documented during follow-up. Variables associated with bleeding were determined using a Cox proportional hazards model, using baseline and time-dependent covariates. RESULTS The 4060 patients in the AFFIRM trial were followed for an average of 3.5 years. Major bleeding occurred in 260 patients, an annual incidence of approximately 2% per year, with no significant difference between the rate-control and rhythm-control groups. Increased age, heart failure, hepatic or renal disease, diabetes, first AF episode, warfarin use, and aspirin use were significantly associated with major bleeding. Minor bleeding was common in both treatment arms, with 738 patients reporting this problem in one or more visits. CONCLUSIONS Bleeding is a significant problem that complicates management of patients with AF. Risk factors for bleeding can be identified, and knowledge of these risk factors can be used to plan therapy.
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Affiliation(s)
- John P DiMarco
- Cardiovascular Division, University of Virginia Health System, Charlottesville, Va 22908, USA.
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8
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Abstract
Grapefruit juice can alter oral drug pharmacokinetics by different mechanisms. Irreversible inactivation of intestinal cytochrome P450 (CYP) 3A4 is produced by commercial grapefruit juice given as a single normal amount (e.g. 200-300 mL) or by whole fresh fruit segments. As a result, presystemic metabolism is reduced and oral drug bioavailability increased. Enhanced oral drug bioavailability can occur 24 hours after juice consumption. Inhibition of P-glycoprotein (P-gp) is a possible mechanism that increases oral drug bioavailability by reducing intestinal and/or hepatic efflux transport. Recently, inhibition of organic anion transporting polypeptides by grapefruit juice was observed in vitro; intestinal uptake transport appeared decreased as oral drug bioavailability was reduced. Numerous medications used in the prevention or treatment of coronary artery disease and its complications have been observed or are predicted to interact with grapefruit juice. Such interactions may increase the risk of rhabdomyolysis when dyslipidemia is treated with the HMG-CoA reductase inhibitors atorvastatin, lovastatin, or simvastatin. Potential alternative agents are pravastatin, fluvastatin, or rosuvastatin. Such interactions might also cause excessive vasodilatation when hypertension is managed with the dihydropyridines felodipine, nicardipine, nifedipine, nisoldipine, or nitrendipine. An alternative agent could be amlodipine. In contrast, the therapeutic effect of the angiotensin II type 1 receptor antagonist losartan may be reduced by grapefruit juice. Grapefruit juice interacting with the antidiabetic agent repaglinide may cause hypoglycemia, and interaction with the appetite suppressant sibutramine may cause elevated BP and HR. In angina pectoris, administration of grapefruit juice could result in atrioventricular conduction disorders with verapamil or attenuated antiplatelet activity with clopidrogel. Grapefruit juice may enhance drug toxicity for antiarrhythmic agents such as amiodarone, quinidine, disopyramide, or propafenone, and for the congestive heart failure drug, carvediol. Some drugs for the treatment of peripheral or central vascular disease also have the potential to interact with grapefruit juice. Interaction with sildenafil, tadalafil, or vardenafil for erectile dysfunction, may cause serious systemic vasodilatation especially when combined with a nitrate. Interaction between ergotamine for migraine and grapefruit juice may cause gangrene or stroke. In stroke, interaction with nimodipine may cause systemic hypotension. If a drug has low inherent oral bioavailability from presystemic metabolism by CYP3A4 or efflux transport by P-gp and the potential to produce serious overdose toxicity, avoidance of grapefruit juice entirely during pharmacotherapy appears mandatory. Although altered drug response is variable among individuals, the outcome is difficult to predict and avoiding the combination will guarantee toxicity is prevented. The elderly are at particular risk, as they are often prescribed medications and frequently consume grapefruit juice.
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Affiliation(s)
- David G Bailey
- Department of Medicine and Lawson Health Research Institute, London Health Sciences Centre, London, Ontario, Canada.
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10
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Abstract
The drug-drug interactions discussed in this article have either documented or suspected clinical relevance for patients with cardiovascular disease and the clinician involved in the care of these patients. Oftentimes, drug-drug interactions are difficult, if not impossible, to predict because of the high degree of interpatient variability in drug disposition. Certain drug-drug interactions, however, may be avoided through knowledge and sound clinical judgment. Every clinician should maintain a working knowledge of reported drug-drug interactions and an understanding of basic pharmacokinetic and pharmacodynamic principles to help predict and minimize the incidence and severity of drug-drug interactions.
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Affiliation(s)
- J R Anderson
- University of New Mexico, College of Pharmacy, Albuquerque, New Mexico, USA
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11
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Matsumoto K, Ishida S, Ueno K, Hashimoto H, Takada M, Tanaka K, Kamakura S, Miyatake K, Shibakawa M. The stereoselective effects of bucolome on the pharmacokinetics and pharmacodynamics of racemic warfarin. J Clin Pharmacol 2001; 41:459-64. [PMID: 11304904 DOI: 10.1177/00912700122010186] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The objective of this study was to investigate the stereoselective influence of bucolome on the pharmacokinetics and pharmacodynamics of warfarin in Japanese inpatients with heart disease. Thirty patients were administered a fixed-maintenance dose of warfarin alone once a day for at least 7 days. The other 25 patients were concomitantly administered warfarin and a 300 mg dose of bucolome once a day, and blood samples were collected on days 1, 4, 7, 14, or 21 after administration of bucolome. Serum concentration of warfarin enantiomers was measured by a chiral reversed-phase HPLC-ultraviolet detection method. The PT-INR was used as a measure of the pharmacodynamic effect of warfarin. Coadministration of bucolome and warfarin had no effect on serum (R)-warfarin concentration and significantly increased serum (S)-warfarin concentration compared with warfarin alone. The PT-INR of warfarin alone was significantly lower with bucolome cotreatment. These results indicate that the augmented anticoagulant effect of warfarin by bucolome is due to inhibition of (S)-warfarin metabolism in vivo. When bucolome is added to a stabilized regimen of warfarin therapy, the dose of warfarin should be reduced by about 30% to 60%, and caution should be exercised during the first 7 days after coadministration of bucolome.
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Affiliation(s)
- K Matsumoto
- Department of Molecular Pathophysiology, Graduate School of Pharmaceutical Sciences, Osaka University, Japan
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12
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Abstract
The management of cardiac arrhythmias has grown more complex in recent years. Despite the recent focus on nonpharmacological therapy, most clinical arrhythmias are treated with existing antiarrhythmics. Because of the narrow therapeutic index of antiarrhythmic agents, potential drug interactions with other medications are of major clinical importance. As most antiarrhythmics are metabolised via the cytochrome P450 enzyme system, pharmacokinetic interactions constitute the majority of clinically significant interactions seen with these agents. Antiarrhythmics may be substrates, inducers or inhibitors of cytochrome P450 enzymes, and many of these metabolic interactions have been characterised. However, many potential interactions have not, and knowledge of how antiarrhythmic agents are metabolised by the cytochrome P450 enzyme system may allow clinicians to predict potential interactions. Drug interactions with Vaughn-Williams Class II (beta-blockers) and Class IV (calcium antagonists) agents have previously been reviewed and are not discussed here. Class I agents, which primarily block fast sodium channels and slow conduction velocity, include quinidine, procainamide, disopyramide, lidocaine (lignocaine), mexiletine, flecainide and propafenone. All of these agents except procainamide are metabolised via the cytochrome P450 system and are involved in a number of drug-drug interactions, including over 20 different interactions with quinidine. Quinidine has been observed to inhibit the metabolism of digoxin, tricyclic antidepressants and codeine. Furthermore, cimetidine, azole antifungals and calcium antagonists can significantly inhibit the metabolism of quinidine. Procainamide is excreted via active tubular secretion, which may be inhibited by cimetidine and trimethoprim. Other Class I agents may affect the disposition of warfarin, theophylline and tricyclic antidepressants. Many of these interactions can significantly affect efficacy and/or toxicity. Of the Class III antiarrhythmics, amiodarone is involved in a significant number of interactions since it is a potent inhibitor of several cytochrome P450 enzymes. It can significantly impair the metabolism of digoxin, theophylline and warfarin. Dosages of digoxin and warfarin should empirically be decreased by one-half when amiodarone therapy is added. In addition to pharmacokinetic interactions, many reports describe the use of antiarrhythmic drug combinations for the treatment of arrhythmias. By combining antiarrhythmic drugs and utilising additive electrophysiological/pharmacodynamic effects, antiarrhythmic efficacy may be improved and toxicity reduced. As medication regimens grow more complex with the aging population, knowledge of existing and potential drug-drug interactions becomes vital for clinicians to optimise drug therapy for every patient.
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Affiliation(s)
- T C Trujillo
- Department of Pharmacy Practice, Massachusetts College of Pharmacy and Health Sciences, Boston 02115, USA.
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13
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Valderrábano M, Singh BN. Electrophysiologic and Antiarrhythmic Effects of Propafenone: Focus on Atrial Fibrillation. J Cardiovasc Pharmacol Ther 1999; 4:183-198. [PMID: 10684540 DOI: 10.1177/107424849900400308] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- M Valderrábano
- Veterans Affairs Medical Center of West Los Angeles, Los Angeles, California, USA
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14
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Abstract
The anticoagulant drug warfarin occurs as a pair of enantiomers that are differentially metabolized by human cytochromes P450 (CYP). R-warfarin is metabolized primarily by CYP1A2 to 6- and 8-hydroxywarfarin, by CYP3A4 to 10-hydroxywarfarin, and by carbonyl reductases to diastereoisomeric alcohols. S-warfarin is metabolized primarily by CYP2C9 to 7-hydroxywarfarin. Potential warfarin-drug interactions could occur with any of a very wide range of drugs that are metabolized by these P450s, and a number of such interactions have been reported. The efficacy of warfarin is affected primarily when metabolism of S-warfarin is altered.
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Affiliation(s)
- L S Kaminsky
- New York State Department of Health, Wadsworth Center, USA
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15
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Abstract
Propafenone hydrochloride, a class 1C antiarrhythmic agent, combines sodium channel-blocking effects with beta-blocking capacities and a weak calcium antagonism. The drug exerts marked electrophysiologic effects on accessory atrioventricular pathways. In patients with atrioventricular nodal reentry tachycardia, propafenone is able to block conduction in the fast conducting pathway. In addition, propafenone is very effective in young patients with supraventricular tachycardia based on enhanced abnormal automaticity. In pediatric patients, left ventricular performance remains unimpaired. Proarrhythmic events have been noted in children only occasionally. In accordance with the electrophysiologic profile, intravenous and oral propafenone is an effective agent for treatment of supraventricular tachycardia based on a reentry mechanism and due to abnormal automaticity (i.e., supraventricular tachycardia based on an accessory atrioventricular pathway, atrioventricular nodal reentry tachycardia, junctional ectopic tachycardia, and atrial ectopic tachycardia). In children with ventricular dysrhythmias, efficacy seems to be related to the underlying cardiac diagnosis. Propafenone is well tolerated in the majority of young patients. Incidence of proarrhythmic events seems to be lower with propafenone than with other class 1C agents. However, the risk of these serious adverse events should be taken into account when therapy with propafenone is considered, particularly in patients with structural heart disease.
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Affiliation(s)
- T Paul
- Children's Hospital, Hannover Medical School, Germany
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16
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Abstract
Oral anticoagulants were introduced in the late 1940s and remain widely used today. Indications include prevention of thrombosis associated with atrial fibrillation, structural cardiac diseases and following prosthetic valvular replacement. They have been used for both treatment and prophylaxis of deep venous thrombosis and in efforts to decrease the frequency and rate of second myocardial infarction. These compounds include the coumarin derivatives [dicoumarol (bishydroxycoumarin), phenprocoumon, nicoumalone (acenocoumarol)] and the indanedione derivatives (diphenadione, phenindione, anisindione) which, because of adverse reactions, are largely unavailable. The oral anticoagulants, and warfarin in particular, are highly interactive with other drugs. Mechanisms of those interactions include both pharmacokinetic and pharmacodynamic mechanisms and may result in either hyper- or hypoprothrombinaemia. Because their principal adverse reaction is haemorrhage, and interactions are widespread across many therapeutic specialties, it becomes imperative for the practising physician to be aware of the possibility of interaction whenever these agents are coadministered with other drugs.
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Affiliation(s)
- M D Freedman
- Johns Hopkins University School of Medicine, Baltimore, Maryland
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17
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Hermans JJ, Thijssen HH. Human liver microsomal metabolism of the enantiomers of warfarin and acenocoumarol: P450 isozyme diversity determines the differences in their pharmacokinetics. Br J Pharmacol 1993; 110:482-90. [PMID: 8220911 PMCID: PMC2175972 DOI: 10.1111/j.1476-5381.1993.tb13836.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
1. To explain the large differences in (the stereoselectivity of) the clearances of the enantiomers of warfarin and acenocoumarol (4'-nitrowarfarin) their human liver microsomal metabolism has been studied and enzyme kinetic parameters determined. The effects of cimetidine, propafenone, sulphaphenazole, and omeprazole on their metabolism has been investigated. 2. The 4-hydroxycoumarins follow similar metabolic routes and are mainly hydroxylated at the 6- and 7-position (accounting for 63 to 99% of the metabolic clearances). 3. Due to the lower Km values of R- and S-acenocoumarol and higher Vmax values of S-acenocoumarol, the overall metabolic clearances of R/S acenocoumarol exceed those of R/S warfarin 6 and 66 times respectively. 4. The metabolism of both compounds is stereoselective for the S-enantiomers, which is 10 times more pronounced in the case of acenocoumarol. 5. Except for the 7-hydroxylation of the R-enantiomers (r = 0.90; P < 0.025), the 6- and 7-hydroxylation rates of R/S warfarin do not correlate with those of R/S acenocoumarol. 6. Sulphaphenazole competitively inhibits the 7- and in some samples partly (up to 50%) the 6-hydroxylation of S-warfarin as well as the 7-hydroxylation of R- and S-acenocoumarol and the 6-hydroxylation of S-acenocoumarol (Kis ranging from 0.5-1.3 microM). 7. Omeprazole partly (40-80%) inhibits the 6- and 7-hydroxylation of R-warfarin (Ki = 99 and 117 microM) and of R- (Ki = 219 and 7.2 microM) and S-acenocoumarol (Ki = 6.1 and 7.7 microM) but not S-warfarin in a competitive manner. 8. Differences in the partial (up to 40%) inhibition of the metabolism of the enantiomers of the 4-hydroxycoumarins were also observed for the relatively weak inhibitors, propafenone and cimetidine.9. The results suggest that the coumarin ring hydroxylations of both compounds are catalysed by different combinations of P450 isozymes. The 7-hydroxylation of R/S acenocoumarol and the 6-hydroxylation of S-acenocoumarol are at least partly conducted by (a) P450 isozyme(s) of the 2C subfamily different from P450 2C9 (the main S-warfarin 7- and 6-hydroxylase).
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Affiliation(s)
- J J Hermans
- Cardiovascular Research Institute Maastricht, Department of Pharmacology, University of Limburg, Maastricht, The Netherlands
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18
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Affiliation(s)
- U Birgersdotter-Green
- Department of Pharmacology, Vanderbilt University, School of Medicine, Nashville, TN 37232
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19
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Hernandez M, Reder RF, Marinchak RA, Rials SJ, Kowey PR. Propafenone for malignant ventricular arrhythmia: an analysis of the literature. Am Heart J 1991; 121:1178-84. [PMID: 2008842 DOI: 10.1016/0002-8703(91)90680-g] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- M Hernandez
- Cardiac Arrhythmia Service, Medical College of Pennsylvania, Philadelphia, PA
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20
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Affiliation(s)
- E N Shen
- John A. Burns School of Medicine, University of Hawaii
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21
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Affiliation(s)
- C Funck-Brentano
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232
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22
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Parker RB, McCollam PL, Bauman JL. Propafenone: a novel type Ic antiarrhythmic agent. DICP : THE ANNALS OF PHARMACOTHERAPY 1989; 23:196-202. [PMID: 2655298 DOI: 10.1177/106002808902300301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Propafenone is an investigational type Ic anti-arrhythmic agent that markedly slows conduction velocity in all cardiac tissues. Propafenone also possesses weak beta- and calcium-channel blocking properties. The bioavailability of propafenone is dose-dependent. Hepatic metabolism of this agent is polymorphic and appears to correlate with the ability of the liver to oxidize debrisoquin sulfate. Propafenone is effective in suppressing spontaneous ventricular ectopy; however, the drug may be less effective in patients with sustained ventricular tachycardia or ventricular fibrillation when evaluated using programmed stimulation. Propafenone is also useful in the treatment of supraventricular tachycardias including atrioventricular (AV) nodal reentrant tachycardia, AV reentrant tachycardia associated with the Wolff-Parkinson-White syndrome, and atrial fibrillation. Adverse reactions seen with propafenone affect the gastrointestinal, central nervous, and cardiovascular systems. Comparative studies with currently available type Ic agents are needed to better define propafenone's place in therapy.
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Affiliation(s)
- R B Parker
- Department of Pharmacy Practice, University of Illinois, Chicago 60612
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Nolan PE, Marcus FI, Erstad BL, Hoyer GL, Furman C, Kirsten EB. Effects of coadministration of propafenone on the pharmacokinetics of digoxin in healthy volunteer subjects. J Clin Pharmacol 1989; 29:46-52. [PMID: 2708548 DOI: 10.1002/j.1552-4604.1989.tb03236.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Previous reports have suggested an interaction between propafenone and digoxin. We investigated the pharmacokinetics of IV digoxin when given alone (Phase I), after pretreatment with propafenone 150 mg every 8 hours for seven days (Phase II), and after propafenone 300 mg every 8 hours for 7 days (Phase III). The total body clearance of digoxin during Phase I was 2.45 ml/min/kg and was 2.17 ml/min/kg during Phase II (NS) and decreased to 1.92 ml/min/kg during Phase III (P less than 0.05). The renal clearance and half-life of digoxin were not significantly altered by propafenone. There was a trend towards a decrease in the volume of distribution of digoxin from 9.43 L/kg in Phase I, to 9.33 L/kg in Phase II, and 8.02 L/kg in Phase III. Similarly there was a trend towards a decreased nonrenal clearance of digoxin from 1.21 ml/min/kg during Phase I to 1.01 ml/min/kg during Phase II and to 0.75 ml/min/kg during Phase III. The changes in volume of distribution and nonrenal clearance parallel each other resulting in no change in the elimination half-life of digoxin. It is postulated that the mechanism of this interaction is due to decreases in the volume of distribution and nonrenal elimination of digoxin by propafenone. The degree of this interaction was related to the dose of propafenone. The magnitude of this interaction may be greater in patients and, thus, may require a reduction in the digoxin dose.
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Affiliation(s)
- P E Nolan
- Department of Pharmacy Practice, College of Pharmacy, University of Arizona, Tucson 85721
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Harron DW, Brogden RN. Propafenone. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic use in the treatment of arrhythmias. Drugs 1987; 34:617-47. [PMID: 3322781 DOI: 10.2165/00003495-198734060-00001] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Propafenone is a Class I antiarrhythmic agent with weak beta-adrenoceptor antagonist activity which can be given both intravenously and orally. Dosage must be individualised because of dose-dependent pharmacokinetics, a wide range of clinically effective plasma concentrations (64 to 3271 micrograms/L) after comparable doses, the presence of an active metabolite (5-hydroxy-propafenone) and genetically determined metabolic oxidation. In non-comparative studies propafenone 450 and 900 mg/day orally significantly suppressed premature ventricular complexes and couplets in 96% and 75% of patients, respectively, and abolished ventricular tachycardia in 75% of patients. Efficacy was confirmed in placebo-controlled studies in which propafenone 300 to 900mg daily suppressed premature ventricular complexes (greater than 80%) in 77% of patients; 87% of patients had significant reductions in couplets and abolition of ventricular tachycardia. In patients with ventricular arrhythmias refractory to other antiarrhythmic agents, propafenone 450 to 1200 mg/day suppressed arrhythmias in 63% of patients (in long term therapy 66%). Electrically induced arrhythmias were prevented by intravenously administered propafenone in 12 to 23% of patients. However, long term oral therapy was effective in 77% of patients selected using programmed electrical stimulation. Propafenone was also effective in suppressing atrial and AV nodal/junctional re-entrant tachycardias and Wolff-Parkinson-White tachycardias involving accessory pathways. A limited number of comparisons with other antiarrhythmic drugs indicate that the antiarrhythmic efficacy of propafenone is superior or similar to that of quinidine, disopyramide and tocainide, and comparable to that of lignocaine (lidocaine), flecainide and metoprolol against ventricular arrhythmias and a smaller number of atrial arrhythmias. Cardiovascular side effects indicate a proarrhythmic effect similar to that with other Class I drugs, occasional precipitation of congestive heart failure and conduction abnormalities; the latter two occur more often in patients with underlying ventricular dysfunction. Non-cardiovascular side effects (neurological, gastrointestinal) are well tolerated and generally resolve with continued therapy or dosage reduction. Thus, propafenone is an effective antiarrhythmic agent, and is a useful addition to currently available drugs, although further studies will be required to determine clearly its place in therapy compared with more established antiarrhythmic drugs.
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