Atrial fibrillation after ondansetron for the prevention and treatment of postoperative nausea and vomiting: a case report

Spinal Anesthesia Reduces Perioperative Polypharmacy and Opioid Burden in Patients Over 65 Who Undergo Transforaminal Lumbar Interbody Fusion

BACKGROUND

Polypharmacy and opioid administration are thought to increase the risk of postoperative cognitive dysfunction and delirium in elderly patients. Spinal anesthesia (SA) holds potential to reduce perioperative polypharmacy in spine surgery. As more geriatric patients undergo spine surgery, understanding how SA can reduce polypharmacy and opioid administration is warranted. We aim to compare the perioperative polypharmacy and dose of administered opioids in patients ≥65 years who undergo transforaminal lumbar interbody fusion (TLIF) under SA versus general anesthesia (GA).

METHODS

A retrospective analysis of 200 patients receiving a single-surgeon TLIF procedure at a single academic center (2014-2021) was performed. Patients underwent the procedure with SA (n = 120) or GA (n = 80). Demographic, procedural, and medication data were extracted from the medical record. Opioid consumption was quantified as morphine milligram equivalents (MME). Statistical analyses included χ2 or Student's t-test.

RESULTS

Patients receiving SA were administered 7.45 medications on average versus 12.7 for GA patients (P < 0.001). Average perioperative opioid consumption was 5.17 MME and 20.2 MME in SA and GA patients, respectively (P < 0.001). The number of patients receiving antiemetics and opioids remained comparable postoperatively, with a mean of 32.2 MME in the GA group versus 27.5 MME in the SA group (P = 0.14). Antiemetics were administered less often as a prophylactic in the SA group (32%) versus 86% in the GA group (P < 0.001).

CONCLUSIONS

SA reduces perioperative polypharmacy in patients ≥65 years undergoing TLIF procedures. Further research is necessary to determine if this reduction correlates to a decrease the incidence of postoperative cognitive dysfunction and delirium.

Drug-induced atrial fibrillation. A narrative review of a forgotten adverse effect

Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with an increased morbidity and mortality. There is clinical evidence that an increasing number of cardiovascular and non-cardiovascular drugs, mainly anticancer drugs, can induce AF either in patients with or without pre-existing cardiac disorders, but drug-induced AF (DIAF) has not received the attention that it might deserve. In many cases DIAF is asymptomatic and paroxysmal and patients recover sinus rhythm spontaneously, but sometimes, DIAF persists, and it is necessary to perform a cardioversion. Furthermore, DIAF is not mentioned in clinical guidelines on the treatment of AF. The risk of DIAF increases in elderly and in patients treated with polypharmacy and with risk factors and comorbidities that commonly coexist with AF. This is the case of cancer patients. Under these circumstances ascribing causality of DIAF to a given drug often represents a clinical challenge. We review the incidence, the pathophysiological mechanisms, risk factors, clinical relevance, and treatment of DIAF. Because of the limited information presently available, further research is needed to obtain a deeper insight into DIAF. Meanwhile, it is important that clinicians are aware of the problem that DIAF represents, recognize which drugs may cause DIAF, and consider the possibility that a drug may be responsible for a new-onset AF episode.

Cardiac Roles of Serotonin (5-HT) and 5-HT-Receptors in Health and Disease

Serotonin acts solely via 5-HT₄-receptors to control human cardiac contractile function. The effects of serotonin via 5-HT₄-receptors lead to positive inotropic and chronotropic effects, as well as arrhythmias, in the human heart. In addition, 5-HT₄-receptors may play a role in sepsis, ischaemia, and reperfusion. These presumptive effects of 5-HT₄-receptors are the focus of the present review. We also discuss the formation and inactivation of serotonin in the body, namely, in the heart. We identify cardiovascular diseases where serotonin might play a causative or additional role. We address the mechanisms which 5-HT₄-receptors can use for cardiac signal transduction and their possible roles in cardiac diseases. We define areas where further research in this regard should be directed in the future, and identify animal models that might be generated to this end. Finally, we discuss in what regard 5-HT₄-receptor agonists or antagonists might be useful drugs that could enter clinical practice. Serotonin has been the target of many studies for decades; thus, we found it timely to summarise our current knowledge here.

Drug-Induced Atrial Fibrillation / Atrial Flutter

Drug-induced atrial fibrillation / flutter (DIAF) is a serious and potentially life-threatening complication of pharmacotherapy. Purpose of the work: systematization and analysis of scientific literature data on drugs, the use of which can cause the development of DIAF, as well as on epidemiology, pathophysiological mechanisms, risk factors, clinical picture, diagnosis and differential diagnosis, treatment and prevention of DIAF. Analysis of the literature has shown that many groups of drugs can cause the development of DIAF, with a greater frequency while taking anticancer drugs, drugs for the treatment of the cardiovascular, bronchopulmonary and central nervous systems. The mechanisms and main risk factors for the development of DIAF have not been finally established and are known only for certain drugs, therefore, this section requires further study. The main symptoms of DIAF are due to the severity of tachycardia and their influence on the parameters of central hemodynamics. For diagnosis, it is necessary to conduct an electrocardiogram (ECG) and Holter monitoring of an ECG and echocardiography. Differential diagnosis should be made with AF, which may be caused by other causes, as well as other rhythm and conduction disturbances. Successful treatment of DIAF is based on the principle of rapid recognition and immediate discontinuation of drugs (if possible), the use of which potentially caused the development of adverse drug reactions (ADR). The choice of management strategy: heart rate control or rhythm control, as well as the method of achievement (medication or non-medication), depends on the specific clinical situation. For the prevention of DIAF, it is necessary to instruct patients about possible symptoms and recommend self-monitoring of the pulse. It is important for practitioners to be wary of the risk of DIAF due to the variety of drugs that can potentially cause this ADR.

Effect of intravenous ondansetron on QTc interval in children with gastroenteritis

BACKGROUND

The potential for ondansetron to cause QT prolongation and fatal dysrhythmia is well-reported, including a 2011 FDA report on the topic. Few clinical trials evaluating this phenomenon in the ED setting exist, and only one is pediatric.

OBJECTIVE

We have sought to determine the effect of a standardized dose of intravenous ondansetron on the QTc duration of children under 14years of age treated for gastroenteritis-associated vomiting in a pediatric ED. This study is modeled closely after an FDA "thorough QT study".

METHODS

EGCs were obtained before and 15, 30, 45, and 60min after a 0.15mg/kg IV dose of ondansetron given for gastroenteritis-associated vomiting. QT intervals were measured manually with digital calipers, and the QTc interval calculated both by Bazett's (QTcB) and Fridericia's (QTcF) correction. A paired t-test comparing QTc was conducted, and frequency of categorical outcomes of prolongation>30msec, >60 msec, and absolute prolongation >450 msec, >480 msec, and >500msec were evaluated.

RESULTS

In a 4-month period, 134 patients were included in the study, 46% were male. The average QTc prior to ondansetron administration was: QTcB 415 msec (95% CI 343-565) and QTcF 373 (95% CI 304-499). The mean difference in QTc after ondansetron was 0.4msec for QTcB (95% CI -35-45msec) and 0.1msec for QTcF (95% CI -40-18msec).

CONCLUSION

In these children, 0.15mg/kg of intravenous ondansetron did not cause prolongation of QTcB or QTcF measured 15min after administration, nor at later times.

Bradycardia After Intravenous Ondansetron with Asystole on Rechallenge: A Case Report

PURPOSE

There have been 3 published reports (4 cases) of symptomatic sinus bradycardia occurring after intravenous (IV) administration of the selective 5-hydroxytryptamine 3 (5-HT₃) receptor antagonist ondansetron. We report a fifth case in which the patient developed asystole after rechallenge with ondansetron.

SUMMARY

A 36-year-old pregnant patient with no cardiac history, status post cerclage for cervical insufficiency, experienced nausea in the post ambulatory care unit after administration of morphine and indomethacin for pain. After IV administration of ondansetron, the patient's heart rate decreased to the 40s and improved spontaneously. The patient experienced a second episode of nausea, another dose of ondansetron was administered, and the patient went into asystole. Advanced cardiac life support measures were initiated and chest compressions were conducted for 3 minutes with return of spontaneous circulation. The patient was monitored overnight with no development of new cardiac arrhythmias and was discharged from the hospital in stable condition.

CONCLUSIONS

Sinus bradycardia after IV administration of ondansetron was observed in a 36-year-old pregnant patient status post cerclage. On rechallenge, the patient went into asystole. This case report adds to the available literature regarding ondansetron-induced cardiac arrhythmias and the possibility of asystole upon rechallenge.

Effect of single doses of IV palonosetron, up to 2.25 mg, on the QTc interval duration: a double-blind, randomized, parallel group study in healthy volunteers

PURPOSE

The use of serotonin type 3 (5-HT3) receptor antagonists (RAs) in the prevention of nausea and vomiting caused by emetogenic chemotherapy is part of a comprehensive management strategy for patients undergoing chemotherapy. Electrocardiographic effects have been reported in patients after intravenous administration of 5-HT3 RAs. The present study investigated the electrocardiogram (ECG) profile of the 5-HT3 RA palonosetron following International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) E14 Guidelines.

METHODS

A total of 221 healthy subjects (101 females, 120 males) were randomized in this phase I, double-blind, double-dummy, parallel group study and assigned to one of five treatments: placebo, palonosetron (0.25, 0.75, or 2.25 mg), or moxifloxacin (400 mg). ECGs were recorded for 24 h pre-dosing until 48 h post-dose. The primary endpoint was the placebo time-matched and baseline-subtracted individual QTc interval prolongation (ΔΔQTcI).

RESULTS

The QTc interval was not prolonged after administration of palonosetron (ΔΔQTcI upper confidence interval was <10 ms for all time points in all palonosetron treatment groups). Assay sensitivity was confirmed with the expected change in the QTc interval after administration of the positive control moxifloxacin.

CONCLUSIONS

Palonosetron, even at supratherapeutic doses, has no effect on cardiac repolarization as measured by the QTc interval in a validated controlled clinical trial.

Effects of Palonosetron on Perioperative Cardiovascular Complications in Patients Undergoing Noncardiac Surgery With General Anesthesia: A Retrospective Cohort Study

We retrospectively investigated whether palonosetron administered during the induction of general anesthesia is associated with an increased risk of perioperative cardiovascular complications in a single tertiary center cohort consisting of 4,517 palonosetron-exposed patients and 4,517 propensity score-matched patients without palonosetron exposure. The primary endpoint was a composite of perioperative cardiovascular complications, including intraoperative cardiac arrhythmia, intraoperative cardiac death, and myocardial injury within the first postoperative week, and there was no significant difference between the groups (odds ratio [OR] = 1.04; 95% confidence interval [CI] = 0.92-1.19). As secondary endpoints, intraoperative cardioversion, cardiac compression, use of cardiovascular drugs, postoperative hospital stay, and in-hospital mortality showed no differences between the groups. However, the palonosetron group showed decreased intraoperative hypotension (OR = 0.88; 95% CI = 0.79-0.97) and length of postoperative intensive care unit (ICU) stay (4.26 ± 9.86 vs. 6.14 ± 16.75; P = 0.026). Palonosetron did not increase the rate of perioperative cardiovascular complications, and can therefore be used safely during anesthetic induction.

Ondansetron and the risk of cardiac arrhythmias: a systematic review and postmarketing analysis

STUDY OBJECTIVE

To explore the risk of cardiac arrhythmias associated with ondansetron administration in the context of recent recommendations for identification of high-risk individuals.

METHODS

We conducted a postmarketing analysis and systematically reviewed the published literature, grey literature, manufacturer's database, Food and Drug Administration Adverse Events Reporting System, and the World Health Organization Individual Safety Case Reports Database (VigiBase). Eligible cases described a documented (or perceived) arrhythmia within 24 hours of ondansetron administration. The primary outcome was arrhythmia occurrence temporally associated with the administration of a single, oral ondansetron dose. Secondary objectives included identifying all cases associating ondansetron administration (any dose, frequency, or route) to an arrhythmia.

RESULTS

Primary: No reports describing an arrhythmia associated with single oral ondansetron dose administration were identified. Secondary: Sixty unique reports were identified. Route of administration was predominantly intravenous (80%). A significant medical history (67%) or concomitant use of a QT-prolonging medication (67%) was identified in 83% of reports. Approximately one third occurred in patients receiving chemotherapeutic agents, many of which are known to prolong the QT interval. An additional third involved administration to prevent postoperative vomiting.

CONCLUSION

Current evidence does not support routine ECG and electrolyte screening before single oral ondansetron dose administration to individuals without known risk factors. Screening should be targeted to high-risk patients and those receiving ondansetron intravenously.

Comparative electrocardiographic effects of intravenous ondansetron and granisetron in patients undergoing surgery for carcinoma breast: A prospective single-blind randomised trial

Background:

Postoperative nausea and vomiting (PONV) are common and distressing symptoms after surgery performed under general anaesthesia. 5-hydroxytryptamine₃ antagonists are routinely used for prevention and treatment of PONV. The aim of our study was to compare the incidence of QTc prolongation and quantify the amount of QTc prolongation with ondansetron and granisetron.

Methods:

This prospective, randomised, single-blind study was carried out in the OT and Recovery Room (RR) of a tertiary referral cancer centre. After obtaining Institutional Review Board approval and written informed consent from the patients, 70 patients undergoing elective surgery for carcinoma breast were included. In the RR, patients randomly received 8 mg of ondansetron or 1 mg of granisetron intravenously. Serial ECGs were recorded at various intervals, Non-invasive blood pressure and SpO₂ were also recorded. Chi-square test and Mann-Whiteny test were used for statistical analysis.

Results:

The demographics were similar in both groups. The incidence of significant QTc prolongation was significantly higher in the ondansetron group (22 of 37 (59.4%) vs. 11 of 33 patients (33.33%) (P<0.05)). There was an increase in the QTc interval in both the groups as compared to the baseline. The median prolongation in QTc interval from baseline was much more in the ondansetron group; this was statistically significant only at 5 and 15 min.

Conclusion:

Granisetron may be a safer option than ondanasetron for prevention and treatment of PONV due to lesser prolongation QTc interval. (ClinicalTrials.gov ID: NCT01352130)

Drug-induced atrial fibrillation

Atrial fibrillation (AF) is a common cardiac arrhythmia that is associated with severe consequences, including symptoms, haemodynamic instability, increased cardiovascular mortality and stroke. While other arrhythmias such as torsades de pointes and sinus bradycardia are more typically thought of as drug induced, AF may also be precipitated by drug therapy, although ascribing causality to drug-associated AF is more difficult than with other drug-induced arrhythmias. Drug-induced AF is more likely to occur in patients with risk factors and co-morbidities that commonly co-exist with AF, such as advanced age, alcohol consumption, family history of AF, hypertension, thyroid dysfunction, sleep apnoea and heart disease. New-onset AF has been associated with cardiovascular drugs such as adenosine, dobutamine and milrinone. In addition, medications such as corticosteroids, ondansetron and antineoplastic agents such as paclitaxel, mitoxantrone and doxorubicin have been reported to induce AF. Whether bisphosphonate drugs are associated with new-onset AF remains controversial and requires further study. The potential contribution of specific drug therapy should be considered when patients present with new-onset AF.

Use of Procainamide for Conversion of Acute Onset AF Following Pericardiocentesis in a Dog

A 9 yr old spayed female golden retriever was evaluated for anorexia and suspected gastric dilatation. Subsequent evaluation the following day determined the dog to have pericardial effusion. Muffled heart sounds and jugular pulses were noted on physical exam, and the dog was diagnosed with pleural and pericardial effusion. A sinus rhythm with a rate of 142 beats/min was documented on a surface electrocardiogram (EKG). Following pericardiocentesis, the heart rate increased to 260 beats/min, the rhythm became irregular, and the systemic blood pressure decreased. Atrial fibrillation (AF) was confirmed by EKG. Procainamide was administered IV over 15 min, resulting in successful conversion of AF to sinus rhythm and clinical improvement. Procainamide is one of several antiarrhythmic medications that are used for the conversion of acute AF in humans; however, its utility and efficacy in dogs in the setting of AF has not previously been reported. This case highlights a unique complication of performing a pericardiocentesis that requires immediate treatment and describes a potential treatment option for the conversion of acute AF in dogs.

Drug-induced atrial fibrillation

INTRODUCTION

Atrial fibrillation (AF) is the most common arrhythmia and an important cause of hospitalization, morbidity, and mortality. A myriad of drugs can induce AF. However, drug-induced AF (DIAF) receives little attention. Thus, this review is an attempt to attract the attention on this adverse effect.

AREAS COVERED

Published reports of drug-induced AF (DIAF) are reviewed in this paper, from January 1974 to December 2011, using the PubMed/Medline database and lateral references.

EXPERT OPINION

In most cases, DIAF is paroxysmal and terminates spontaneously, but sometimes AF persists and it is necessary to perform a cardioversion to restore sinus rhythm and avoid progression to persistent AF. Because of the short duration of DIAF, in addition to physicians/patients not being knowledgeable about this side effect, the real incidence and clinical consequences of DIAF are presently unknown. DIAF is an increasing problem, as some widely prescribed drugs can present this adverse effect. The risk is expected to increase in the elderly and in patients with comorbidities. It is important that physicians understand the significance of DIAF, to increase the collaboration between cardiac and non-cardiac professionals, and to educate patients to make them aware of this adverse side effect.

Reappraisal of the role of dolasetron in prevention and treatment of nausea and vomiting associated with surgery or chemotherapy

Chemotherapy-induced nausea and vomiting and postoperative nausea and vomiting are one of the most frequent but also very concerning consequences for patients undergoing chemotherapy or surgical procedures under general anesthesia. There are a variety of mechanisms involved in the activation of nausea and vomiting. Serotonin, a ubiquitous central and peripheral neurotransmitter, is thought to be the predominant mediator of the perception of nausea and triggering of the vomiting response in both the brain and the periphery via the 5-hydroxytryptamine type 3 (5-HT₃) receptor pathways. 5-HT₃ receptor antagonists disrupt this pathway, largely at the level of the vagal afferent pathways, to decrease nausea and vomiting. This review will focus on dolasetron, an older but sill commonly used 5-HT₃ receptor antagonist and its multimodal mechanism of action, safety and tolerability, patient considerations, and a review of the current literature on its use to combat both chemotherapy-induced and postoperative nausea and vomiting in these two important patient populations.

Exploring the binding mechanism of ondansetron hydrochloride to serum albumins: spectroscopic approach

The mechanism of interaction of ondansetron hydrochloride (OND) to serum albumins [bovine serum albumin (BSA) and human serum albumin (HSA)] was studied for the first time employing fluorimetric, circular dichroism, FTIR and UV-vis absorption techniques under the simulated physiological conditions. Fluorimetric results were utilized to investigate the binding and conformational characteristics of protein upon interaction with varying concentrations of the drug. Higher binding constant values revealed the strong interaction between the drug and protein while the number of binding sites close to unity indicated single class of binding site for OND in protein. Thermodynamic results revealed that both hydrogen bond and hydrophobic interactions played a major role in stabilizing drug-protein complex. Site marker competitive experiments indicated that the OND bound to albumins at subdomin II A (Sudlow's site I). Further, the binding distance between OND and serum albumin was calculated based on the Förster's theory of non-radioactive energy transfer and found to be 2.30 and 3.41 nm, respectively for OND-BSA and OND-HSA. The circular dichroism data revealed that the presence of OND decreased the α-helix content of serum albumins. 3D-fluorescence results also indicated the conformational changes in protein upon interaction with OND. Further, the effects of some cations have been investigated in the interaction of drug to protein.

Acute effect of palonosetron on electrocardiographic parameters in cancer patients: a prospective study

OBJECTIVES

Palonosetron is a novel 5-hydroxytryptamine(3) (5 HT(3)) receptor antagonist, which has been shown to be superior to first generation 5 HT(3) receptor antagonists regarding the prevention of acute, delayed and overall chemotherapy-induced nausea and vomiting. First generation 5 HT(3) receptor antagonists may induce electrocardiographic changes of heart rate and repolarization. The acute cardiac effect of palonosteron is unknown. The purpose of this study is to determine acute effects of palonosetron on electrocardiographic (ECG) parameters in cancer patients.

MATERIALS AND METHODS

The study had a prospective design. Seventy-six cancer patients with normal cardiac function who received palonosetron for prevention of chemotherapy-induced nausea and vomiting were enrolled. Standard 12-lead ECG recordings were performed at baseline and 30 min after palonosetron administration. P wave durations and corrected QT intervals were measured; P wave dispersion (Pd) and QTc dispersion were calculated.

RESULTS

Median heart rate did not differ among 76 patients enrolled before and after palonosetron administration (p: 0.6). Systolic and diastolic blood pressures were not significantly different before and after palonosteron (p values 0.9 and 0.3, respectively). Although median QT min value was higher after palonosetron administration than before palonosetron administration, the difference was not statistically significant (p: 0.6).

CONCLUSION

Palonosetron seems to have no acute arrhythmogenic potential.

Pharmacologic management of postoperative nausea and vomiting

INTRODUCTION

As advances in the safety and efficacy of surgery and anesthesia have been made, other complications such as postoperative nausea and vomiting (PONV) have become more apparent. PONV occurs after 30% of all surgeries, and incidences as high as 80% have been reported among patients at high risk.

AREAS COVERED

This review provides a brief overview of the etiology and mechanisms of emesis and of known risk factors for PONV. It also covers pharmacologic therapies, appropriate management strategies, prophylactic strategies, multimodal therapy and rescue treatment.

EXPERT OPINION

The main triggers for PONV are general anesthesia with inhalational anesthetics and opioids. When given to susceptible patients, e.g., females, the risk may be as high as 80%. In such patients, opioid-free regional anesthesia would be the most logical approach. However, if general anesthesia is needed, we prefer total intravenous anesthesia as it eliminates the use of inhalational anesthetics and reduces the risk for PONV. Importantly, efficacy of antiemetic interventions is independent as long as interventions have different mechanisms. Thus, for practical purposes, we prefer to titrate the use of antiemetics according to the validated Apfel simplified risk score. If a patient has 0, 1, 2, 3 or 4 of the four risk factors, we apply a similar number of antiemetic strategies.

Ondansetron induced fatal ventricular tachycardia

Ondansetron is a serotonin receptor antagonist used widely in the prophylaxis and treatment of postoperative nausea and vomiting (PONV) and vomiting associated with cancer chemotherapy. The common side effects of ondansetron are fever, malaise, diarrhoea, constipation, and allergic reactions. Extra-pyramidal reactions are rare and cardiovascular side effects are even rarer. Even though its clinical safety has been established in a large number of studies, its adverse effects have been reported and these include cardiovascular events like acute myocardial ischemia and arrhythmias in adults.([1]) Studies of its adverse effects in children are few. We report a rare adverse effect of ondansetron in a 14-year-old girl, presenting as ventricular tachycardia.

Symptomatic sinus bradycardia: A rare adverse effect of intravenous ondansetron

Ondansetron is a serotonin receptor antagonist which has been used frequently to reduce the incidence of post-operative nausea and vomiting in laparoscopic surgery. It has become very popular drug for the prevention of post-operative nausea and vomiting due to its superiority in-terms of efficacy as well as lack of side effects and drug interactions. Although cardiovascular adverse effects of this drug are rare, we found a case of symptomatic sinus bradycardia in a 43-year-old female patient, going for laparoscopic cholecystectomy, who developed the same after she was given intravenous ondansetron in operation theater during premedication. Hence, we report this case, as the rare possibility of encountering bradycardia effect after intravenous administration of ondansetron should be born in mind.

Coronary Vasospasm and Atrial Fibrillation Associated with Ondansetron Therapy

Objective:

To provide further evidence of cardiovascular adverse effects of ondansetron, including new-onset atrial fibrillation, ST segment elevation, and chest pain subsequent to ondansetron administration, and to review cardiovascular adverse events related to several 5-hydroxytryptamine type 3 (5-HT3) receptor antagonists.

Case Summary:

A 51-year-old male with an uncomplicated past medical history was admitted for an elective inguinal hernia repair and septoplasty. His maintenance medications were discontinued prior to surgery. After a second 4-mg dose of intravenous ondansetron was administered, he developed nausea and diaphoresis. His electrocardiograph revealed new-onset atrial fibrillation and inferolateral ST segment elevation with ST segment alternans. During emergent cardiac catheterization, no obstructive coronary artery disease was evident. The patient's heart rhythm was electrically converted to normal sinus rhythm. During 3 years of follow-up, he has had no return of chest pain or hypotension.

Discussion:

Although considered a safe class of medications by many clinicians, several of the 5-HT3 receptor antagonists have been associated with serious cardiovascular effects. Three case reports described cardiac dysrhythmias and 9 documented coronary vasospasm and chest pain, possibly resulting from ondansetron. This is the first reported case of a combination of hypotension, atrial fibrillation, ST segment elevation, and chest pain following ondansetron administration after elective surgery in a healthy adult male with a nonconfounding medication profile. The Naranjo probability scale indicated that ondansetron was the probable cause of these cardiovascular events.

Conclusions:

This case report supports the concern regarding cardiovascular adverse effects of ondansetron. Clinicians should be aware of cardiovascular adverse reactions that may be associated with intravenous ondansetron and monitor for electrocardiographic changes as indicated. Further investigation is needed to delineate the actual incidence of cardiovascular effects associated with ondansetron and whether the intravenous rate of administration is a contributing factor.

Haloperidol is as effective as ondansetron for preventing postoperative nausea and vomiting

PURPOSE

Recent warnings regarding the safety of droperidol have limited use of this drug as an antiemetic. Haloperidol, a butyrophenone derivative similar to droperidol, has not been rigorously evaluated as an antiemetic. The aim of this study was to compare the prophylactic antiemetic efficacy of haloperidol vs ondansetron for the prevention of postoperative nausea and vomiting (PONV) after general anesthesia.

METHODS

Ninety non-smoking female patients were eligible to participate in this randomized double-blinded study. Approximately 30 min before the end of surgery, patients were randomly assigned to receive either haloperidol 2 mg iv, or ondansetron 4 mg iv, respectively. The incidence of PONV, average pain and sedation scores, recovery times, and changes of the rate-corrected QT (QTc) interval were observed postoperatively.

RESULTS

The proportion of patients who experienced PONV in the first 24 hr was similar in the two groups (28% and 26% for haloperidol and ondansetron groups, respectively). The incidence of PONV was significantly less in both groups than predicted according to the patients' underlying risks (53% for the haloperidol group, P=0.016; 51% for the ondansetron group, P=0.015). Pain scores, sedation scores, and recovery times were similar in the two groups, and no prolongation of the QTc interval was observed in either group.

CONCLUSIONS

Haloperidol 2 mg iv given 30 min before the end of surgery is effective in preventing PONV, with efficacy comparable to ondansetron 4 mg iv for the first 24 hr after general anesthesia.

Early and late arrhythmogenic effects of doxorubicin

BACKGROUND

To determine the incidence of early and late arrhythmogenic effects of doxorubicin-containing chemotherapy regimens.

PATIENTS AND METHODS

A prospective study including 29 patients who were treated with doxorubicin-containing regimens. Cardiac evaluation was based on 24-hour electrocardiographic monitorization (Holter), which was performed during the first cycle of doxorubicin-containing regimens, as well as after the last cycle of chemotherapy.

RESULTS

The mean age of the patients was 45.8 +/- 15.1 (range 18-69). Holter records obtained during the first cycle of treatment revealed varying arrhythmias in 19 patients (65.5%) and in 18 (62.1%) patients after completion of therapy. One patient presented with syncope and both Mobitz Type 2 atrioventricular block and complete atrioventricular block were demonstrated. The patient subsequently underwent permanent pacemaker implantation.

CONCLUSIONS

Doxorubicin may result in arrhythmias both in early and late periods of treatment. These arrhythmias are rarely life threatening.

Meta-analysis of the safety of 5-HT3 antagonists with dexamethasone or droperidol for prevention of PONV

BACKGROUND

Antiemetic guidelines recommend a combination of serotonin (5-HT3) with a second agent such as droperidol or dexamethasone. Physicians have been reluctant to employ these guidelines due to concerns over the black-box warning of droperidol and safety concerns with a steroid.

OBJECTIVE

To assess the safety profiles of 5-HT3 receptor antagonist (5-HT3RA) monotherapy and combination therapy with a steroid or droperidol for prophylaxis of postoperative nausea and vomiting (PONV).

METHODS

A MEDLINE search of English-language reports of randomized controlled trials (RCTs) was conducted (1966-September 2005) using the key terms 5-HT3, granisetron, ondansetron, dolasetron, tropisetron, PONV, postoperative, vomiting, emesis, and nausea. RCTs with treatment arms comparing 5-HT3RA monotherapy (granisetron, ondansetron, dolasetron, or tropisetron) with dexamethasone or droperidol or 5-HT3RA combinations and providing incidence data on adverse events were identified and reviewed. Within-study odds ratios with 95% confidence intervals were calculated to determine the incidence rates of all adverse events in RCTs using 5-HT3RA monotherapy and combination therapies. Overall effect sizes for frequently reported adverse events were estimated by pooling ORs using fixed- and random-effect models.

RESULTS

Pooled ORs (OR(pooled)) for adverse events with 5-HT3RA/dexamethasone versus 5-HT3RA for PONV prophylaxis were not significant for any reported adverse events or the overall incidence of adverse events; 5-HT3RA/droperidol versus 5-HT3RA was significant only for decreased headache incidence (fixed model: OR(pooled) 0.35; 95% CI 0.18 to 0.69). The OR(pooled) for 5-HT3RA/dexamethasone versus dexamethasone was not significant for any reported adverse events except headaches (fixed model OR(pooled) 1.75; 95% CI 1.01 to 3.03), none of which was serious. OR(pooled) for 5-HT3RA/droperidol versus droperidol was not significant for any reported adverse events. Avascular necrosis, occult infection, and delayed wound healing were not observed with either combination therapy. Cardiac abnormalities were observed with 5-HT3RA/droperidol therapy.

CONCLUSIONS

This meta-analysis indicates that either therapy has a safety profile similar to that of dexamethasone, droperidol, or 5-HT3RA.

Prophylaxis of Postoperative Nausea and Vomiting in Patients Scheduled for Breast Surgery

Breast surgery performed under general anaesthesia is associated with a high incidence of postoperative nausea and vomiting (PONV). Between 60% and 80% of patients undergoing mastectomy (with axillary dissection) experience PONV. Pharmacological approaches have been investigated to reduce PONV after breast surgery. Traditional antiemetics (droperidol and metoclopramide) are frequently used for the prevention of PONV during the first 24 hours after anaesthesia. The available non-traditional antiemetics that have been shown to be effective for prophylaxis against PONV are dexamethasone, clonidine, propofol and supplemental oxygen. Antiserotonins (ondansetron, granisetron, tropisetron, dolasetron and ramosetron) are highly effective for preventing PONV for 24 hours postoperatively, compared with traditional antiemetics. Ramosetron is effective for the long-term (up to 48 hours) prevention of PONV. Better results can be obtained by combining antiemetics, because they have different sites of action. Combination antiemetic therapy is often effective for preventing PONV after breast surgery. Combinations of an antiserotonin (granisetron or dolasetron) and droperidol or dexamethasone are more effective than monotherapy with antiserotonins. A non-pharmacological technique is acupuncture at the P6 (Nei-Kuan) point. Overall, these pharmacological and non-pharmacological approaches reduce the incidence of PONV following breast surgery. Most of the published trials indicate improved prophylaxis of PONV following breast surgery by avoiding risk factors, and by using effective antiemetic agents in women scheduled for mastectomy (with axillary dissection). The clinician must weigh the benefits of using pharmacological and non-pharmacological approaches for PONV against the risk of occurrence of adverse events.