quetiapine-fumarate and Hypokalemia

Torsade de pointes is a potentially lethal polymorphic ventricular tachyarrhythmia that can occur in the setting of long QT syndrome (LQTS). LQTS is multi-hit in nature and multiple factors combine their effects leading to increased arrhythmic risk. While hypokalemia and multiple medications are accounted for in LQTS, the arrhythmogenic role of systemic inflammation is increasingly recognized but often overlooked. We tested the hypothesis that the inflammatory cytokine interleukin(IL)-6 will significantly increase the incidence of arrhythmia when combined with other pro-arrhythmic conditions (hypokalemia and the psychotropic medication, quetiapine).. Guinea pigs were injected intraperitoneally with IL-6/soluble IL-6 receptor and QT changes were measured in vivo. Subsequently, hearts were cannulated via Langendorff perfusion for ex vivo optical mapping measurements of action potential duration (APD. IL-6 prolonged QTc in vivo guinea pigs from 306.74 ± 7.19 ms to 332.60 ± 8.75 ms (n = 8, p = .0021). Optical mapping on isolated hearts demonstrated APD prolongation in IL-6- vs saline groups (3Hz APD. Our experimental observations strongly suggest that controlling inflammation, specifically IL-6, could be a viable and important route for reducing QT prolongation and arrhythmia incidence in the clinical setting.

Topics: Animals; Arrhythmias, Cardiac; Cytokines; Electrocardiography; Guinea Pigs; Hypokalemia; Inflammation; Interleukin-6; Long QT Syndrome; Quetiapine Fumarate; Torsades de Pointes

Topics: Anti-Bacterial Agents; Antipsychotic Agents; Bipolar Disorder; Diuretics; Electrocardiography; Female; Heart Failure; Humans; Hypokalemia; Inappropriate Prescribing; Middle Aged; Pneumonia; Quetiapine Fumarate; Torsades de Pointes; Treatment Outcome

Topics: Adolescent; Anorexia Nervosa; Antidepressive Agents; Antipsychotic Agents; Depressive Disorder, Major; Diagnosis, Differential; Dibenzothiazepines; Duloxetine Hydrochloride; Electrocardiography; Female; Humans; Hypokalemia; Quetiapine Fumarate; Suicide, Attempted; Thiophenes; Unconsciousness

Acquired long QT interval has been widely reported to be a consequence of drug therapy and electrolyte disturbances. We describe two cases of multifactorial acquired QT interval prolongation and torsades de pointes. In the first case, the drugs venlafaxine, amiodarone and domperidone may have contributed to QT interval prolongation in a patient with hypokalemia and hypomagnesaemia. In the second case, QT interval prolongation occurred in a patient taking quetiapine and citalopram, and whose use of hydrocholorothiazide and history of chronic alcohol abuse likely contributed by rendering the patient hypokalemic. These cases highlight the potential risks associated with polypharmacy and demonstrate that though torsades de pointes is an uncommon arrhythmia, the combination of multiple factors known to prolong QT interval may precipitate this life-threatening arrhythmia.

Topics: Alcoholism; Amiodarone; Antipsychotic Agents; Arrhythmias, Cardiac; Biomarkers; Citalopram; Cyclohexanols; Dibenzothiazepines; Diuretics; Domperidone; Dopamine Antagonists; Electrocardiography; Female; Humans; Hydrochlorothiazide; Hypokalemia; Magnesium; Middle Aged; Polypharmacy; Quetiapine Fumarate; Risk Factors; Selective Serotonin Reuptake Inhibitors; Torsades de Pointes; Treatment Outcome; Venlafaxine Hydrochloride

Topics: Adult; Antipsychotic Agents; Asian People; Dibenzothiazepines; Dose-Response Relationship, Drug; Humans; Hypokalemia; Male; Potassium; Quetiapine Fumarate; Schizophrenia

Topics: Adult; Antipsychotic Agents; Dibenzothiazepines; Drug Overdose; Humans; Hypokalemia; Male; Quetiapine Fumarate; Risperidone