Arrhythmias drug-induced

Decreased Cardiac Output related to adverse drug reactions (drug-induced arrhythmias)... 

Drug-induced torsades de pointes rarely occurs inpatients without specific risk factors for the arrhythmia (Table 6—14). In most cases, administration of a drug known to cause torsades de pointes is unlikely to cause the arrhythmia however, the... 

Tisdale JE. Arrhythmias. In Tisdale JE, Miller DA, eds. Drug-Induced Diseases. Prevention, Detection and Management. Bethesda, MD American Society of Health-Systems Pharmacists 2005 289-327. 

First, drug-induced lengthening of the QT interval has been associated with the occurrence of ventricular tachyarrhythmias, namely TdP, a polymorphous ventricular arrhythmia that may cause syncope and degenerate into ventricular fibrillation and sudden death although the incidence of TdP is a rare event (usually, less than 1 in 100 000) [32], even a low risk is not justified for drugs with uncertain benefits or drugs providing only symptomatic improvement of a mild disease. 

Finally, the ICH E14 guideline does not address the possible consequences of QT/ QTc shortening, which may be associated with significant arrhythmias [5,167]. Digitalis intoxication is a known example of drug-induced short QT syndrome associated with polymorphic ventricular tachycardia [ 168]. It should be acknowledged that this is an area of active research and no guidelines can be put forward at the moment. 

Liu, K., Yang, T., Viswanathan, P.C. and Roden, D.M. (2005) New mechanism contributing to drug-induced arrhythmia rescue of a misprocessed LQT3 mutant. Circulation, 112, 3239-3246. 

Napolitano, C., Schwartz, P.J., Brown, A.M., Ronchetti, E., Bianchi, L., Pinnavaia, A., Acquaro, G. and Priori, S.G. (2000) Evidence for a cardiac ion channel mutation underlying drug-induced QT prolongation and life-threatening arrhythmias. Journal of Cardiovascular Electrophysiology, 11, 691-696. 

Cardiovascular Bradycardia and arrhythmia (block of atrio-ventricular conduction) used as surrogate of drug-induced QT prolongation Milan et al. 224 Ulrike et al.225... 

Ulrike, L., Gabriele, V., and Thomas, W., Zebrafish embryos express an orthologue of HERG and are sensitive toward a rank of QT-prolonging drugs inducing severe arrhythmia, Toxicol. Appl. Phamacol., 193, 370-382, 2003. 

Hypersensitivity or idiosyncrasy to quinidine or other cinchona derivatives manifested by thrombocytopenia, skin eruption or febrile reactions myasthenia gravis history of thrombocytopenic purpura associated with quinidine administration digitalis intoxication manifested by arrhythmias or AV conduction disorders complete heart block left bundle branch block or other severe intraventricular conduction defects exhibiting marked QRS widening or bizarre complexes complete AV block with an AV nodal or idioventricular pacemaker aberrant ectopic impulses and abnormal rhythms due to escape mechanisms history of drug-induced torsade de pointes history of long QT syndrome. 

Oral- Amiodarone may cause a clinical syndrome of cough and progressive dyspnea accompanied by functional, radiographic, gallium scan, and pathological data consistent with pulmonary toxicity. The frequency varies from 2% to 17% fatalities occur in about 10% of cases. However, in patients with life-threatening arrhythmias, discontinuation of amiodarone therapy due to suspected drug-induced pulmonary toxicity should be undertaken with caution. 

Scherer, C.R., Lerche, C., Decher, N., Dennis, A.T., Maier, P., Picker, E., Busch, A.E., Wollnik, B. and Steinmeyer, K. (2002) The antihistamine fexofenadine does not affect l(Kr) currents in a case report of drug-induced cardiac arrhythmia. British Journal of Pharmacology, 137, 892-900. 

Doig JC. Drug-induced cardiac arrhythmias. Incidence, prevention and management. Drug Saf 1997 17(4) 265-75. 

Aonuma S, Kohama Y, Makino T, Hattori K Studies on heart. XXII. Inhibitory effect of an atrial peptide on several drug-induced arrhythmias in vivo. Yakugaku Zasshi 1983 103 662-666. 

Podrid PJ Aggravation of ventricular arrhythmia. A drug induced complication. Drugs 1985 29(suppl 4) 33 14. 

Proarrhythmic effects of antiarrhythmic drugs In the Cardiac Arrhythmia Suppression Trial (CAST) treatment with encainide and flecainide, two class IC antiarrhythmic agents, successfully prevented ventricular ectopic beats in patients who had myocardial infarction. However, continued therapy with either drug was associated with a two- to three-fold increase in death due to cardiac arrhythmias. Similar results were reported for moricizine. Increased death was probably due to drug-induced fatal arrhythmias triggered by recurrent myocardial ischemia. 

Adverse effects Flecainide can cause dizziness, blurred vision, headache, and nausea. Like other Class IC drugs, flecainide can aggravate preexisting arrhythmias or induce life-threatening ventricular tachycardia that is resistant to treatment (see p. 166). 

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