Sudden death in phenothiazine therapy. (A clinicopathologic study of 12 cases)

A Summary of Current Information, Mechanisms and Treatment

Adverse reactions and the possible mechanisms of the reactions caused by antipsychotics are reviewed. The mechanisms of many of these adverse reactions have not been elucidated to date, hence there have been inconsistent approaches to the problem. Complicated symptoms of the reactions, especially exacerbation of the mental state, are often considered to be a part of the psychosis under treatment. Some of the reactions are temporary, or the patient may develop tolerance to them so that an additional drug may not be necessary.

It is suggested that use of the minimum dosage of antipsychotics, avoidance of polypharmacy, and close observation of the patient constitute the best approach to the prevention of unwanted reactions.

Managing cardiovascular disease risk in patients treated with antipsychotics: a multidisciplinary approach

Background

The use of antipsychotic medication in the United States and throughout the world has greatly increased over the last fifteen years. These drugs have significant side effect burdens, many of them relating to cardiovascular health.

Objective

To review the available evidence on the major cardiovascular issues that arise in patients taking antipsychotic medication.

Method

A PubMed literature review was performed to identify recent meta-analyses, review articles, and large studies. Further articles were identified through cited papers and based on expert consultation when necessary.

Results

Clinical guidance on the following adverse effects and antipsychotics was reviewed: electrocardiogram (ECG) changes, (specifically, prolonged QT and risk of torsades de pointes), weight gain, dyslipidemia, metabolic syndrome, and myocarditis. Specific attention was paid to monitoring guidelines and treatment options in the event of adverse events, including dose change, medication switch, or adjuvant therapy.

Connecting patient needs with treatment management

OBJECTIVE

To propose ideas for the development of a core strategy for monitoring patients with schizophrenia to ensure physical health and optimal treatment provision.

METHOD

A panel of European experts in the field of schizophrenia met in Bordeaux in June 2006 to discuss, 'Patient management optimisation through improved treatment monitoring.'

RESULTS

Key consensus from the discussion deemed that weight gain, oral health and ECG parameters were core baseline parameters to be monitored in all patients with schizophrenia. Further, an identification of a patient's own barriers to treatment alongside local health service strategies might comprise elements of an individualised management strategy which would contribute to optimisation of treatment. Any monitoring strategy should be kept simple to encourage physician compliance.

CONCLUSION

A practical solution to the difficulties of providing holistic patient care would be to suggest a limited set of physical parameters to be monitored by physicians on a regular basis.

Atypical antipsychotics: from potassium channels to torsade de pointes and sudden death

Syncope and sudden death are features of schizophrenia that can be attributed to ischaemic heart disease, the use of antipsychotics (because of proarrhythmia or other reasons such as pharyngeal dyskinesia) or the psychiatric disease itself. Cases have been described with most antipsychotics and have led to the withdrawal, temporary suspension from the market or restricted use of antipsychotics, such as sultopride, droperidol, sertindole or thioridazine. Reviewing the available data shows that all antipsychotics tested affect the cardiac potassium channel, with the concentration that produces 50% inhibition (IC50) ranging from 1 nmol/L (haloperidol) to 6 micromol/L (olanzapine). Experimental in vitro or in vivo electrophysiological studies have shown a dose-dependent increase in the duration of the action potential with various degrees of indicators of serious arrhythmogenicity. However, this does not always translate clinically into an increased duration of the QT interval or increased risk of torsade de pointes or sudden death in clinical trials or pharmacoepidemiological studies. In turn, QT prolongation in clinical trials does not always translate to an increased risk of torsade de pointes or sudden death. The reasons for these apparent discrepancies are unclear and could be related to insufficiently powered field studies, low plasma and tissue drug concentrations with reference to in vitro data or drug effects on other receptors or ion channels that have a protective effect. Alternatively, risks that were not apparent from preclinical or clinical data could be related to the use of the drug in high-risk patients, metabolic interactions or other factors that would only be encountered in large postmarketing populations. The assessment of cardiovascular safety, both preclinical and during premarketing clinical trials, needs to be supported by appropriately powered pharmacoepidemiology studies.

Determination of myocardium to plasma concentration ratios of five antipsychotic drugs: comparison with their ability to induce arrhythmia and sudden death in clinical practice

Reviewing available data shows that most of antipsychotic drugs are associated with arrhythmia and sudden death. Experimental studies have shown a HERG channel blockade, a dose-dependent increase in duration of action potential or of QT interval, with various degrees of indicators of serious arrhythmogenicity. However, it seems difficult to relate these in vitro and in vivo preclinical models to clinical findings, in part, because the relationship between concentrations used and in vivo tissue concentrations during treatment in man is not known. Consequently, we established the myocardium to plasma concentration ratios for a series of antipsychotic drugs by intraperitoneal administration of different level doses to the guinea pig. Then, we compared these values to their ability to induce arrhythmia or torsade de pointes in clinical practice. The myocardium to plasma concentration ratios were 2.2 for clozapine, 2.7 for olanzapine, 3.1 for sertindole, 4.5 for risperidone, and 6.4 for haloperidol. These data suggest that when the ratio is higher than 4, arrhythmia and sudden death may be expected. On the contrary, when the ratio is less than 3, little effect may be predicted. These results underscore the importance of interpreting HERG channel data and electrophysiological data in the context of other pharmacokinetic parameters such as myocardium to plasma distribution.

Torsades de pointes associated with chlorpromazine: case report and review of associated ventricular arrhythmias

PURPOSE

To present a case of chlorpromazine-associated torsades de pointes, review established cases of ventricular arrhythmias associated with chlorpromazine, and describe the proarrhythmic characteristics of this drug.

DATA SOURCES

Articles identified through a search of MEDLINE and IDIS from January 1966-November 2000 and thorough review of the article bibliographies. Patient cases also were identified from a search of the Food and Drug Administration's Adverse Event Reporting System database (November 1997-March 2001). Cases involving intentional overdoses of chlorpromazine were excluded.

RESULTS

In addition to the case reported herein, 12 cases of documented, chlorpromazine-associated ventricular arrhythmias were identified; five had characteristic features of torsades de pointes. Chlorpromazine delayed repolarization and produced electrocardiographic abnormalities; although, whether chlorpromazine induced torsades de pointes through a mechanism of early afterdepolarizations is unclear. Similar to other instances of drug-induced torsades de pointes, concurrent factors such as electrolyte deficiencies may place the patient at increased risk for arrhythmia.

CONCLUSIONS

Chlorpromazine can delay repolarization and produce electrocardiographic abnormalities. These can result infrequently in ventricular arrhythmias and torsades de pointes, particularly in patients with confounding factors.

Thioridazine, diarrhoea and torsades de pointe

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Choking incidents among psychiatric patients: retrospective analysis of thirty-one cases from the west Bologna psychiatric wards

OBJECTIVE

To determine the rate of choking incidents among the psychiatric population of 4 inpatient facilities, classifying the incidents according to their probable etiology.

METHOD

All incidents recorded over 18 months were retrospectively analyzed for demographic variables, psychiatric and medical diagnoses, and drug therapy at the time of incident. Where possible, patients underwent psychiatric, neurological, and medical examination.

RESULTS

Thirty-one incidents were recorded involving 18 patients at a rate of one incident every 56.32 months' hospitalization per person. One case proved fatal, one patient died several weeks after the incident from aspiration pneumonia, and 5 patients needed reanimation or the Heimlich manoeuvre. Etiological classification showed that incidents due to bradykinetic dysphagia and "fast eating" were the most numerous, even among the fatal or grave cases.

CONCLUSIONS

Various simple, effective preventive measures emerge from the study.

Neuroleptic induced sudden death--a case report and critical review

A case report illustrates possible pathophysiological mechanisms of sudden death in psychiatric patients. Difficulties with the tendency to implicate phenothiazines as the cause of death are discussed in light of evidence that the death investigation and autopsy are often incomplete. Some suggestions are made to reduce the risk of a fatal outcome following a violent incident.

Cardiotoxicity more common in thioridazine overdose than with other neuroleptics

On the basis of case reports and small non-comparative series it has been suggested that thioridazine has greater cardiotoxicity in overdose. Limited evidence also suggests an increased association with sudden death in therapeutic doses. The aim of our study is to examine the clinical and electrocardiographic features associated with neuroleptic poisoning and compare thioridazine with other neuroleptics. Consecutive adult patients with neuroleptic poisoning presenting to metropolitan hospitals in Newcastle between 1987 and 1993 were studied. The main outcome measures examined were ECG changes (QRS, QT and QTc intervals), arrhythmias, seizures, degree of sedation, heart rate and blood pressure. Two-hundred ninety-nine patients had ingested thioridazine (104), chlorpromazine (69), trifluoperazine (36), pericyazine (35), haloperidol (33), prochlorperazine (18), fluphenazine (8), or other neuroleptics (7). Sixteen patients had ingested more than one neuroleptic and were excluded from comparative analysis. Thioridazine was more likely to cause tachycardia (odds ratio 1.7, 95% CI 1.1-2.9, p = 0.03), a prolonged QT interval (odds ratio 5.2, 95% CI 1.6-17.1, p = 0.006), prolonged QTc > 450 ms1/2 (odds ratio 4.7, 95% CI 2.7-7.9, p = 0.001), a widened QRS (> 100 ms) (odds ratio 3.1, 95% CI 1.5-6.3, p = 0.001) and arrhythmias (odds ratio infinity, 95% CI 2.4- infinity, p = 0.004). There were no significant differences in the odds of coma (odds ratio 0.5 (0.2-1.5)), hypotension (odds ratio 0.9 (0.4-1.9)) or seizures (odds ratio 3.9 (0.3-43.5)). Adjustment for age, sex, dose ingested and co-ingestion of tricyclic antidepressants or lithium had no major effect on the odds ratios observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Phenothiazine-associated supraventricular tachycardia

Psychotropic medications, mainly phenothiazines, are known to be associated with cardiac insult. The case report presented here describes nearly fatal arrhythmia (sustained supraventricular tachycardia) consequent to phenothiazine treatment. The authors aim to alert psychiatrists to the possible adverse, and even fatal, effects of phenothiazines.

Anesthetic management with eptazocine hydrobromide in patients receiving long-term antipsychotic medication

We evaluated the usefulness of eptazocine hydrobromide as an adjuvant in patients receiving antipsychotics for long periods. Patients anesthetized with enflurane alone (enflurane group, n = 11), were compared with those anesthetized with enflurane and eptazocine hydrobromide 1 mg.kg(-1) (eptazocine group, n = 10). The mean daily dose of the antipsychotics, converted into the amount of chlorpromazine, was 345 mg in the eptazocine group and 366 mg in the enflurane group. The duration of antipsychotic medication was 14 years in the eptazocine group and 17 years in the enflurane group. The maintenance concentration of enflurane was 0.37% in the eptazocine group and 0.67% in the enflurane group, being significantly lower in the former group. The interval between the termination of operation and removal of the endotracheal tube was slightly shorter in the eptazocine group. The discriminant function of circulatory stability obtained from the measurement of systolic blood pressure and heart rate during anesthesia in the eptazocine group was 481, being significantly lower than 539 in the enflurane group. Both absolute and relative instabilities of systolic blood pressure and heart rate were slightly smaller in the eptazocine group. No side effects associated with eptazocine hydrobromide administration were observed. These results suggest the safety and usefulness of this analgesic in the anesthetic management of patients receiving long-term antipsychotic medication.

The effect of neuroleptic and antiparkinsonian medication on the gag reflex

A polygraph assessment of medicated psychiatric patients suggests anticholinergic effects are the primary cause of a diminished gag reflex. Sex differences indicate that females are relatively protected.

Magnesium therapy in ventricular arrhythmias

Magnesium (Mg) is the known activator of 300 enzymes which govern energy utilization, cell permeability, and ionic membrane currents in the cardiac conducting cells. This may explain the antiarrhythmic efficacy of Mg in specific clinical settings, despite its only modest electrophysiological effects. This review summarizes the effect of Mg administration in four clinical conditions: in digitalis toxicity; in drug-induced torsade de pointes; in patients with chronic diuretic therapy; and in acute myocardial infarction. Mg effectively abolished ventricular tachyarrhythmias associated with digitalis intoxication. This effect of Mg is related to the activation of sodium-potassium ATP-ase, which is inhibited by digitalis. Drug-induced torsade de pointes was promptly abolished by Mg sulfate in the clinical setting. Experimental studies showed that Mg suppresses the early afterdepolarizations and the triggered activity responsible for occurrence of the arrhythmia. In diuretic-treated hypertensives, potassium depletion has been associated with increased ventricular ectopy and sudden death. Mg has been found to be an important adjuvant for intracellular repletion of potassium in these patients. Several randomized, double-blind studies in patients with acute infarction showed that Mg administered on admission improved survival or reduced the incidence of complex ventricular arrhythmias. Thus, Mg should be employed as first-line therapy in digitalis intoxication and drug-related torsade de pointes, and should be considered an important adjuvant therapy in hypertensives treated with diuretics and patients with acute myocardial infarction.

Acute laryngeal dystonic reactions to neuroleptics

Two cases of acute laryngeal dystonia (laryngospasm), a rarely reported extrapyramidal reaction to neuroleptics, occurred in a public psychiatric hospital. A review of the literature revealed only seven well-documented case reports. This article discusses the clinical significance of this rare, alarming, and probably underreported phenomenon. Factors related to recognition, prediction, and management are also discussed. The review strongly advocates immediate intravenous administration of anticholinergic drugs to relieve dystonia.

Does chlorpromazine produce cardiac arrhythmia via the central nervous system?

The influence of the central nervous system in the production of phenothiazine-induced arrhythmia and death was examined in this study. In a series of cats, spinal cords were transected at the atlanto-occipital junction prior to the 1 mg/kg/min, i.v. infusion of chlorpromazine or thioridazine. No protection against drug-induced arrhythmia or death was afforded by this procedure. In other cats, 6OH-dopamine was administered prior to intravenous injection of atropine and infusion of chlorpromazine, 1 mg/kg/min. In these in situ denervated heart preparations, there was no protection against chlorpromazine-induced arrhythmia or death. In alpha-chloralose anesthetized cats, 0.5 mg chlorpromazine administered intracerebroventricularly did not induce arrhythmia or death, although blood pressure decreased initially. Thus, chlorpromazine or thioridazine do not appear to produce arrhythmia or death via a central locus and may instead be acting directly on myocardial conduction to produce arrhythmia and death.

The QT-sensitive cybernetic pacemaker: a new role for an old parameter?

A critical review of the available data on QT interval is presented to delineate techniques useful to the development of a QT-sensitive cybernetic pacemaker. The reason for the development of this unit stems from the ability of QT prolongation to predict the onset of life-threatening ventricular arrhythmias in some clinical situations; the QT interval is physiologically related to the cardiac cycle length, therefore providing adequate information to drive both ventricular and atrioventricular sequential rate-responsive pacemakers. This unit might also monitor cardiac rhythm and detect the pathophysiologic precursors of advanced grades of ventricular arrhythmias. A therapeutic role, both pharmacologic and electrical, may also be possible in the future. Integration of these concepts and cooperation between interested physicians, technicians and manufactors will be necessary to produce such a unit at a low cost-benefit ratio. The potential clinical application of this pacemaker deserves attention for the prophylaxis and treatment of sudden arrhythmic death.

Polymorphous ventricular tachycardia associated with normal and long Q-T intervals

Polymorphous ventricular tachycardia may occur in the setting of either a normal or a prolonged Q-T interval. Torsade de pointes is a form of polymorphous ventricular tachycardia in which the polarity of the QRS complex exhibits phasic alterations in both axis and rate. Traditionally, torsade de pointes has been described in association with a variety of congenital and acquired (including drug and metabolic) causes of Q-T prolongation. The distinction between torsade de pointes and those polymorphous ventricular tachycardias occurring in patients with a normal Q-T interval has important therapeutic implications. The former requires strict avoidance of all drugs that may potentially further delay repolarization, including class I antiarrhythmic agents; immediately, the initiation of cardiac pacing is often necessary for control of arrhythmia, and on a long-term basis, sympathetic nervous blockade is often efficacious. In contrast, the polymorphous ventricular tachycardias with a normal Q-T interval usually respond to conventional therapy, including administration of class I antiarrhythmic agents. Thus, the management of polymorphous ventricular tachycardia should be based on the presence of absence of associated repolarization rather than on the morphologic features of the tachycardia. Unfortunately, recent advances in basic and clinical electrophysiology have not yet elucidated the pathophysiologic basis for these arrhythmias, although this is an area of active investigative interest.

Management of recurrent ventricular tachyarrhythmias associated with Q-T prolongation

Eleven patients with acquired prolongation of the Q-Tc interval and recurrent ventricular tachyarrhythmias were studied. Five patients required 5 to 44 direct current shocks to correct prolonged ventricular tachyarrhythmias, and five were given at least two antiarrhythmic agents in an attempt to control the arrhythmias. In 4 of the 11 patients, when thioridazine, diuretic drugs and antiarrhythmic agents were withdrawn and hypokalemia or hypocalcemia corrected, ventricular tachyarrhythmias did not recur. The Q-Tc interval normalized in 2 to 3 days. Ventricular tachyarrhythmias were recurrent in the remaining seven patients, despite withdrawal of the drugs that caused the Q-Tc prolongation, attempted correction of hypokalemia when present and the administration of antiarrhythmic agents to four of the seven. All antiarrhythmic agents were then withdrawn in this group. Immediately on the establishment of overdrive ventricular or atrioventricular sequential pacing in these patients, ventricular tachyarrhythmias were abolished. No breakthrough ventricular tachyarrhythmias occurred during temporary pacing. Temporary pacing was required for an average of 10 days and the Q-Tc interval normalized an average of 5 days from the onset of pacing. Three patients required a permanent pacemaker, one because of chronic complete heart block, one because of the sick sinus syndrome, and one because of frequent ventricular ectopic complexes complicating ischemic heart disease. All 11 patients survived their period of hospitalization.

Hemolytic anemia associated with chlorpromazine therapy

A rare case of hemolytic anemia is presented which occurred on exposure to chlorpromazine and resolved when the medication was discontinued. Another complication, absent gag reflex, is also discussed.

Cardiovascular side effects of phenothiazines and tricyclic antidepressants. A review with precautionary measures

A well-documented association exists between the phenothiazines and the tricyclic antidepressants and such alarming side effects as cardiac arrhythmias, ECG changes, and even sudden death. Most disturbing is the fact that major and possibly fatal arrhythmias can occur in young adults without antecedent heart disease who are receiving therapeutic dosages of these psychotropic drugs (especially thioridazine). Further study of the cardiovascular side effects of psychotropic drugs is needed to clarify the association. In the meantime, it is mandatory that physicians individualize treatment programs that include these drugs and carefully monitor patient response.

Hypothyroidism, psychotropic drugs and cardiotoxicity

The effects of hypothyroidism are protean, involving many systems. Electrocardiographic changes are almost invariable, and include bradycardia, low QRS voltage and flattened T waves: these are usually reversible with replacement therapy (McDonald, 1978). Psychiatric disturbances are also well known, although they are seldom the presenting feature and are notorious for mistakes in diagnosis (Lishman, 1978; Whybrow and Ferrell, 1974). Most such disturbances comprise apathy and depression, some an organic reaction and a few manifest as an acute schizophrenia-like psychosis. Phenothiazines, the most generally used neuroleptic medication, may interfere with cardiac conduction. When hypothyroidism presents as acute psychosis and the patient is hypersensitive to phenothiazines a dangerous situation can arise.

Electrocardiographic changes and cardiac arrhythmias in patients receiving psychotropic drugs

Eight patients had cardiac manifestations that were life-threatening in five while taking psychotropic drugs, either phenothiazines or tricyclic antidepressants. Although most patients were receiving several drugs, Mellaril (thioridazine) appeared to be responsible for five cases of ventricular tachycardia, one of which was fatal in a 35 year old woman. Supraventricular tachycardia developed in one patient receiving Thorazine (chlorpromazine). Aventyl (nortriptyline) and Elavil (amitriptyline) each produced left bundle branch block in a 73 year old woman. Electrocardiographic T and U wave abnormalities were present in most patients. The ventricular arrhythmias responded to intravenous administration of lidocaine and to direct current electric shock; ventricular pacing was required in some instances and intravenous administration of propranolol combined with ventricular pacing in one. The tachyarrhythmias generally subsided within 48 hours after administration of the drugs was stopped. Five of the eight patients were 50 years of age or younger; only one clearly had antecedent heart disease. Major cardiac arrhythmias are a potential hazard in patients without heart disease who are receiving customary therapeutic doses of psychotropic drugs. A prospective clinical trial is suggested to quantify the risk of cardiac complications to patients receiving phenothiazines or tricyclic antidepressant drugs.