Occurrence of graft-versus-host disease increases mortality after umbilical cord blood transplantation for acute myeloid leukaemia: a report from Eurocord and the ALWP of the EBMT

BACKGROUND

The efficacy of umbilical cord blood transplantation (UCBT) as treatment for acute myeloid leukaemia (AML) relies on immune-mediated graft-versus-leukaemia effects. Previous studies have suggested a strong association between graft-versus-host disease (GVHD) occurrence and graft-versus-leukaemia effects after allogeneic hematopoietic cell transplantation.

METHODS

Here, we evaluated the kinetics of relapse rate in correlation with GVHD occurrence after UCBT. The kinetics of relapse rate over time in correlation to GVHD occurrence were assessed by calculating the relapse rate per patient-year within sequential 90-day intervals. The impact of GVHD on relapse and mortality was further studied in multivariate Cox models handling GVHD as a time-dependent covariate.

RESULTS

The study included data from 1068 patients given single (n = 567) or double (n = 501) UCBT. The proportion of patients with grade II, III and IV acute GVHD was 20%, 7% and 4%, respectively. At 2 years, the cumulative incidence of chronic GVHD was 42%, the cumulative incidence of relapse was 32%, and overall survival was 32% as well. Relapse rates declined gradually over time during the first 30 months after transplantation. There was a possible suggestion that grade II-IV acute (HR = 0.8, P = 0.1) and chronic (HR = 0.65, P = 0.1) GVHD decreased relapse risk. However, grade II-IV acute GVHD significantly increased early (the first 18 months after UCBT) mortality (HR = 1.3, P = 0.02), whilst chronic GVHD increased each early (HR = 2.7, P < 0.001) and late (HR = 4.9, P < 0.001) mortality after UCBT.

CONCLUSIONS

The occurrence of grade II-IV acute or chronic GVHD each increases overall mortality after UCBT for AML mitigating the possible graft-versus-leukemia effect of GVHD.

Clinical impact of NK-cell reconstitution after reduced intensity conditioned unrelated cord blood transplantation in patients with acute myeloid leukemia: analysis of a prospective phase II multicenter trial on behalf of the Société Française de Greffe de Moelle Osseuse et Thérapie Cellulaire and Eurocord

Unrelated cord blood transplantation (UCBT) after a reduced intensity conditioning regimen (RIC) has extended the use of UCB in elderly patients and those with co-morbidities without an HLA-identical donor, although post-transplant relapse remains a concern in high-risk acute myeloid leukemia (AML) patients. HLA incompatibilities between donor and recipient might enhance the alloreactivity of natural killer (NK) cells after allogeneic hematopoietic stem-cell transplantation (HSCT). We studied the reconstitution of NK cells and KIR-L mismatch in 54 patients who underwent a RIC-UCBT for AML in CR in a prospective phase II clinical trial. After RIC-UCBT, NK cells displayed phenotypic features of both activation and immaturity. Restoration of their polyfunctional capacities depended on the timing of their acquisition of phenotypic markers of maturity. The incidence of treatment-related mortality (TRM) was correlated with low CD16 expression (P=0.043) and high HLA-DR expression (P=0.0008), whereas overall survival was associated with increased frequency of NK-cell degranulation (P=0.001). These features reflect a general impairment of the NK licensing process in HLA-mismatched HSCT and may aid the development of future strategies for selecting optimal UCB units and enhancing immune recovery.

90Y-ibritumomab tiuxetan, fludarabine, busulfan and antithymocyte globulin reduced-intensity allogeneic transplant conditioning for patients with advanced and high-risk B-cell lymphomas

BACKGROUND

Patients with advanced B-cell non-Hodgkin's lymphoma (NHL) refractory to initial chemotherapy or relapsing after autologous stem-cell transplantation have a poor prognosis. Allogeneic stem-cell transplantation after reduced-intensity conditioning (RIC) regimen can be a therapeutic option. However, the high incidence of relapse remains a challenging issue. We speculated that the incorporation of (90)Y-Ibritumomab tiuxetan into a fludarabine-based RIC regimen would improve the lymphoma control without overwhelming toxicity. Our aim was to evaluate the safety of (90)Y-Ibritumomab tiuxetan in association with such a regimen in a prospective multicenter phase II trial.

PATIENTS AND METHODS

Thirty-one patients with advanced lymphoma from five distinct institutions were included between February 2008 and October 2010. Thirty patients in complete or partial response after failure of a median of 3 (range, 2-4) previous chemotherapy regimens including autologous transplant in 29 were evaluable for nonrelapse mortality (NRM) at day 100 post-transplant that was the primary end point.

RESULTS

With a median follow-up of 32 months (range, 29-60 months), the 2-year event-free and overall survivals of the whole study group were both 80% [95 confidence interval (CI) 60.8% to 90.5%). The 100-day and 2-year post-transplant cumulative incidences of NRM were 3.3% (95% CI 0.2% to 14.9%) and 13.3% (95% CI 5.4% to 33.2%), respectively. The 2-year cumulative incidence of relapse was 6.7% (95% CI 1.7% to 25.4%). The cumulative incidences of grade II-IV and extensive chronic graft-versus-host disease were 27% and 14%, respectively.

CONCLUSIONS

For chemosensitive advanced high-risk B-cell lymphoma, the addition of (90)Y-Ibritumomab tiuxetan to a RIC regimen based on fludarabine, busulfan and antithymocyte globulin followed by allogeneic transplant is safe and highly effective. clinicaltrials.gov: NCT00607854.

Allogeneic stem cell immunotherapy for advanced metastatic breast cancer

e12012

Background: Despite continuous progress, advanced breast cancer (ABC) remains an incurable disease. Immunotherapy using allogeneic stem cell transplantation (ASCT) has been proven successful in malignant hematological diseases. We have investigated ASCT as a possible way of improving tumor control in ABC. Methods: Between 1998 and 2008, 21 ABC pts underwent ASCT after the same reduced intensity conditioning (RIC) based on fludarabine, busulfan and ATG or low dose irradiation from a HLA-identical sibling. Results: Pre-treatment characteristics of pts receiving ASCT were the following: ER or PR +, 79%; HER-2+, 27%; liver metastasis, 48%; adjuvant chemotherapy, 90%; median number of metastatic sites, 2 (1–4); 95% have received anthracyclines and/or taxanes; 71% have received endocrine therapy; 48% received more than 2 lines of cytotoxics; median age at transplant was 39 years (range 22–57). At time of transplant, 48% pts had progressive disease (PD), and 52% pts had a stable disease (SD). All pts engrafted and none died from transplant related mortality. While outcome was uniformly poor for pts with PD (no response and no surviving pt at 2 years), pts with SD achieved a 36% response rate (p = 0.09) and a 55% (CI95%, 28–79%) overall survival (OS) probability at 2 years (p = 0.001). To better assess the impact of ASCT, we looked for control group. During the same period, a total of 93 pts were searched for a HLA match sibling: 41 pts had an identified donor while 52 had no donor (group A). Of those 41 pts with a donor, 21 proceeded to transplant (group C) and 20 did not (group B). Reasons for not proceeding to transplant when a donor was found were: disease progression: 12 pts; patient decision: 6 pts; referring MD decision: 2pts. Progression-free survivals (PFS) were assessed from the first day of the last therapy immediately preceding HLA typing. Median PFS were 7.4 (CI95%, 6.2–12.4), 5.7 (CI95%, 4.6–12.8), and 18.2 (CI95%, 12.9–30.7) months for groups A, B, and C, respectively and were strikingly different between the 3 groups (p = 0.014). OS were not different. Conclusions: ASCT can be safely performed in ABC and may provide an outcome advantage to selected pts deserving further investigations.

No significant financial relationships to disclose.

Allogeneic immunotherapy by hematopoietic stem cell transplantation (ASCT) after reduced intensity conditioning (RIC) following high-dose chemotherapy for patients with acute myeloblastic leukemia (AML) in first complete remission (CR1): Reduced toxicity

7098

Background: RIC-based ASCT can be used after intensive chemotherapy in pts with CR1AML(Blaise, Cancer, 2005). Initial disease control was high and was not related to selection bias (Mohty, Leukemia, 2005).Here, we investigated if this control was maintained after a long follow-up. Methods: 37 pts (age: 51 (26–60)) with high risk clinical characteristics (70%) (Age = 50 (N=22, 59%); severe comorbidity (30%)) and/or poor risk leukemic features (65%) (Cytogenetics (35%); 2 induction courses (27%); secondary leukemia (11%), High white blood cell counts(14%) or partial remission (3%)) were treated. After CR1, pts received at least either 1 course of high dose cytarabine (24 g/m2) and anthracycline (HIDAC: N=21) or HIDAC + 1 course of. melphalan (140 mg/m2) (HDMEL) with auto-SCT Pts (HIDAC +HDM N=16). All pts were then scheduled to receive ASCT prepared with RIC (fludarabine (180 mg/m2), busulfan (8 mg/kg), Thymoglobulin (2.5 to 10 mg/kg)) followed with BMT (28%) or PBSC (72%). Results: With a Median follow-up of 3 years (16–70 mths). 15 pts experienced aGVHD (grade 2–4 aGVHD cumulative incidence (CI):22% (9–35). 10 and 14 pts presented a limited and extensive cGVHD respectively (CI cGVHD:65 % (50–80). 3 deaths were attributed to non-relapse causes (NRD) (AGVHD: 1; CGVHD: 2° (NRD CI: 8% (0–17). In all, 9 pts relapsed at 5 mths (2–19) (24% (9–35). Relapse was associated with the absence of cGVHD (cGVHD: 8 (0–19), no cGVHD 44% (12–76), p=.05). 25 pts are still alive in CR1 for overall survival and leukemia-free survival (LFS) probability estimates at 4 years of 65 % (48–79%) and 66% (49–80%) respectively. When restricting the analysis to the 33 pts evaluable for cGVHD, cGVHD remained the only independent risk factor positively influencing LFS (cGVHD: 81% (59–92); no cGVHD (56% (27–81), p=.05) Conclusions: We conclude that RIC Allo-SCT preceded by adequate prior intensive chemotherapy might offers a relatively low NRD while exerting a sustained leukemia control even in high risk pts deserving prospective evaluation against standard strategy of conventional Allo SCT.

No significant financial relationships to disclose.

The benefit of reduced intensity conditioning (RIC) allogeneic stem cell transplantation (allo-SCT) as salvage treatment for relapsing multiple myeloma (MM)

8045

Background: The role of RIC allo-SCT in MM is still controversial. This single centre study aimed to evaluate RIC allo- SCT for relapsed MM, using a genetic randomization through a donor vs. no donor comparison. Methods: Between 2002 and 2005, 32 patients with relapsed or refractory MM, and with an identified sibling, were referred to our centre for HLA typing. In all, 19 patients (59%; donor group) had an HLA-identical sibling donor, while the remaining 13 pts (41%; no donor group) had no HLA-identical sibling donor. There were no significant differences between these two groups that were comparable as for demographic, disease and prognosis factors. All pts had previously failed auto-SCT. Results: Among the 19 pts from the donor group, 18 (95%) could proceed to allo-SCT. With a median overall FU of 36 m., 11 patients (85%; 95%CI: 54–98%) from the no donor group had disease progression despite salvage therapy, and only 6 of them are still alive, of whom 5 (80%) in progressive disease at last FU. In contrast, only 5 pts (28%;P=0.001) from the donor group progressed after RIC allo-SCT. In the RIC allo-SCT group, 10 pts (56%;95%CI;33–79%) are still alive, with 4 pts being in CR, and 5 in PR or VGPR. Only one patient is currently experiencing disease progression and receiving salvage therapy. Interestingly, 11 pts (61%;95%CI,39–83%) from the RIC allo-SCT group showed objective disease response, usually concurrent to chronic GVHD. In all, 6 pts died from TRM for an overall incidence of TRM of 33% (95%CI,11–55%) in this population of heavily pretreated and relapsed or refractory MM population. In an intention-to- treat analysis, the KM estimate of progression-free survival was significantly higher in the donor group as compared to the no donor group (P=0.01; 46% vs. 8% at 3 y.). Conclusions: RIC allo-SCT from an HLA-identical sibling is a feasible and potential therapy that should be proposed for refractory or relapsed MM, since a potent graft-vs. -MM effect can be induced despite heavy pretreatments, allowing for significantly longer PFS. Also, the latter results are expected to be further improved with the systematic and early use of maintenance therapies after RIC allo-SCT.

No significant financial relationships to disclose.

Alterations in prodynorphin gene expression and dynorphin levels in different brain regions after chronic administration of 14-methoxymetopon and oxycodone-6-oxime

Previous studies showed that opioid drugs-oxycodone-6-oxime and 14-methoxy-5-methyl-dihydromorphinone (14-methoxymetopon)-produced less respiratory depressive effect and slower rate of tolerance and dependence, respectively. It was also reported that morphine decreased the prodynorphin gene expression in the rat hippocampus, striatum and hypothalamus. In this study, we determined the prodynorphin gene expression and dynorphin levels in selected brain regions of opioid tolerant rats. We found that in the striatum morphine decreased, while oxycodone-6-oxime increased and 14-methoxymetopon did not alter the prodynorphin gene expression. In the nucleus accumbens, morphine and oxycodone-6-oxime did not change, while 14-methoxymetopon increased the prodynorphin gene expression. In the hippocampus both oxycodone-6-oxime and 14-methoxymetopon enhanced, whereas morphine did not alter the prodynorphin gene expression. In the rat striatum only oxycodone-6-oxime increased dynorphin levels significantly in accordance with the prodynorphin mRNA changes. In the hippocampus both opioid agonists increased the dynorphin levels significantly similarly to the augmented prodynorphin gene expression. In ventral tegmental area only 14-methoxymetopon increased dynorphin levels significantly. In nucleus accumbens and the temporal-parietal cortex the changes in the prodynorphin gene expression and the dynorphin levels did not correlate. Since the endogenous prodynorphin system may play a modulatory role in the development of opioid tolerance, the elevated supraspinal dynorphin levels appear to be partly responsible for the reduced degree of tolerance induced by the investigated opioids.

Phenolphthalein and Bisacodyl: Assessment of Genotoxic and Carcinogenic Responses in Heterozygous p53 (+/−) Mice and Syrian Hamster Embryo (SHE) Assay

Phenolphthalein (800 and 2400 mg/kg/day by gavage and 2400 mg/kg/day by diet) and bisacodyl (800-500, 4000-2000, and 8000 mg/kg/day by gavage) were administered to 15 male and 15 female and 20 male and 20 female p53(+/-) mice respectively for 26 weeks to investigate the potential carcinogenicity of each compound. Toxicokinetic analyses confirmed systemic exposure. p-Cresidine was administered by gavage (400 mg/kg/day) and served as the positive control agent in each study. Dietary phenolphthalein reduced survival in both sexes and early deaths were attributed to thymic lymphoma. No bisacodyl-related neoplasms were observed. Regardless of route of administration to p53(+/-) mice, phenolphthalein but not bisacodyl was unequivocally genotoxic, causing increased micronuclei in polychromatic erythrocytes. In the Syrian hamster embryo (SHE) cell transformation assay, phenolphthalein caused increases in morphologically transformed colonies, thereby corroborating NTP's earlier reports, showing phenolophthalein has potential carcinogenic activity. Bisacodyl was negative in the SHE assay. Results of these experiments confirm an earlier demonstration that dietary phenolphthalein causes thymic lymphoma in p53(+/-) mice and show that (1) phenolphthalein causes qualitatively identical results in this transgenic model regardless of route of oral administration, (2) phenolphthalein shows evidence of micronucleus induction in p53(+/-) mice for up to 26 weeks, (3) phenolphthalein induced transformations in the in vitro SHE assay, and (4) bisacodyl in p53(+/-) mice induces neither drug-related neoplasm, nor micronuclei in polychromatic erythrocytes, and did not induce transformations in the in vitro SHE assay.

Serotonin reuptake inhibitors fluoxetine and citalopram relax intestinal smooth muscle

Selective serotonin reuptake inhibitor antidepressants (SSRIs) exert depressant effects on cardiac myocytes and vascular smooth muscle cells by inhibiting Ca2+ channels. We hypothesized that the SSRIs fluoxetine and citalopram affect the contractile activity of intestinal smooth muscle by interfering with Ca2+ entry and (or) signaling pathways. The effects of fluoxetine and citalopram on contractions of guinea-pig ileum longitudinal muscle-myenteric plexus preparations (LMMP) were compared with the effects of the voltage-operated Ca2+ channel inhibitors nifedipine and diltiazem. In a concentration-dependent manner, nifedipine, diltiazem, fluoxetine, and citalopram elicited relaxation of LMMPs contracted by electrical field stimulation (EC50 values of 4 x 10(-7) M, 1.4 x 10(-6) M, 1.4 x 10(-5), and 6.8 x 10(-6) M, respectively). Nifedipine, diltiazem, fluoxetine, and citalopram also relaxed LMMPs contracted with a depolarizing concentration of KCl (48 mM; EC50 values of 1.8 x 10(-8) M, 1.4 x 10(-7) M, 3.7 x 10(-6) M, and 6.3 x 10(-6), respectively), a response that could be reversed by increasing the extracellular Ca2+ concentration (2.5-30 mM). These data suggest that fluoxetine and citalopram elicit relaxation of intestinal smooth muscle, likely by inhibiting Ca2+ channel(s). This effect may be of clinical importance.

Current trends in the development of new antidepressants

Early antidepressant medications e.g. tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAOIs) are effective because they enhance either noradrenergic or serotonergic mechanisms, or both. Unfortunately, these compounds block cholinergic, histaminergic and alpha-1-adrenergic receptor sites, interact with a number of other medications and bring about numerous undesirable side effects. Several chemically unrelated agents have been developed and introduced in the past decade to supplement the early antidepressants. These include selective inhibitors of the reuptake of serotonin (the selective serotonin reuptake inhibitors (SSRIs)) or noradrenaline (reboxetine) or both (SNRIs: milnacipran and venlafaxine), as well as drugs with distinct neurochemical profiles such as mirtazapine, nefazodone, moclobemide and tianeptine. All these newer compounds are the results of rational developmental strategies to find drugs that were as effective as the TCAs but of higher safety and tolerability profile. In spite of the remarkable structural diversity, most currently introduced antidepressants are monoamin based and modulating monoamine activity as a therapeutic strategy continues to dominate antidepressant research. It must be emphasised, however, that these newer antidepressants are far from the ideal ones, also resulting in undesirable side effects and requiring 2-6 weeks of treatment to produce therapeutic effect. Furthermore, approximately 30% of the population do not respond to current therapies. An important new development has been the emergence of potential novel mechanisms of action beyond the monoaminergic synapse. The results of recent novel developmental approaches have suggested that modulation of N-methyl-D-aspartate (NMDA), neuropeptide (substance P and corticotrophin-releasing factor) receptors and the intracellular messenger system may provide an entirely new set of potential therapeutic targets. This paper discusses the advances from monoamine-based treatment strategies and looks at the future developments in the treatment of depression.

Involvement of the opioid system in the central antisecretory action of alpha-2 adrenoceptor agonists in rat

The aim of the present study was to analyse the role of the central alpha-2 adrenoceptors in the regulation of gastric acid secretion in pylorus ligated rats. It was found that the intracerebroventricularly (icv.) injected presynaptic alpha-2 adrenoceptor agonist clonidine and the alpha-2A adrenoceptor subtype selective stimulant oxymetazoline exerted a dose dependent inhibition on gastric acid secretion. The antisecretory ED(50) values for clonidine and oxymetazoline were 20 and 7.5 nmol/rat icv., respectively. The antisecretory effect of these compounds was antagonised by the presynaptic adrenoceptor antagonist yohimbine (50 nmol/rat icv.) indicating that the action is mediated through central presynaptic alpha-2 adrenoceptors. Moreover, naloxone (50 nmol/rat icv.)--non-selective opioid antagonist--and naltrindole (0.5 nmol/rat icv.)--delta-opioid receptor selective antagonist--also decreased the antisecretory effect of clonidine and oxymetazoline suggesting that the endogenous opioid system is likely to be involved in the central antisecretory action of alpha-2 adrenoceptor stimulants.

Organ donation in children: role of the pediatric intensive care unit

OBJECTIVES

Children waiting for organ transplants continue to die because of the shortage of available organs. Studies of organ donation in children are scarce. The evaluation of the organ donation experience in a pediatric tertiary care hospital may identify factors that influence actual organ donation rates and lead to strategies to improve pediatric organ donation.

DESIGN

Retrospective study.

SETTING

Pediatric intensive care unit in a Canadian pediatric referral center.

PATIENTS

All children with brain death over an 8-yr period (1990-1997).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 199 children who fulfilled the criteria for brain death, 153 were medically suitable for organ donation. Families were approached for consent to organ donation in 128 (84%) of the 153 suitable cases. Consent was obtained in 63% (81/128) of those asked. Brain death caused by acute neurosurgical lesions was highly correlated to medical suitability and consent. Families identified as ethnic minorities were significantly more likely to refuse. After consent was granted, organs were procured from 63 (78%) of 81 donors, for an average of 3.6 organs transplanted per donor. There was a failure to procure organs in 22% (18/81) of cases after consent had been granted, primarily as a result of cardiocirculatory instability while in the intensive care unit.

CONCLUSIONS

Despite an encouraging 63% consent rate for organ donation when families are approached, only 41% of potential donors proceeded to actual donation. Strategies for a prospective pediatric study should focus on mandatory request, multicultural issues, and aggressive postconsent medical management and procurement. The pivotal role of the pediatric intensive care unit practitioner should be emphasized.

Speculations on difference between tricyclic and selective serotonin reuptake inhibitor antidepressants on their cardiac effects. Is there any?

The cardiovascular effects and toxicity of tricyclic antidepressants (TCAs) have been well documented in medical literature. The most common manifestation of such effects is slowing of intraventricular conduction, manifested by prolonged PR, QRS and QT intervals on the standard electrocardiogram (ECG) and postural hypotension. In contrast to TCAs, selective serotonin reuptake inhibitors (SSRIs), including fluoxetine and citalopram, are considered to cause less effect on cardiac impulse conduction. In addition, these compounds induced significantly less anticholinergic, antihistaminergic and cardiotoxic side-effects than TCAs. However, there is an increasing number of case reports on dysrhythmias, like atrial fibrillation or bradycardia and syncope associated with fluoxetine and another SSRI treatment and overdose. Although such reports have not been common, they do raise concerns. In cardiac tissues isolated from canine, rabbit, rat and guinea pig hearts we have found that fluoxetine and citalopram inhibited cardiac Na+ and Ca2+ channels. These direct cardiac electrophysiological effects were similar to those of observed for tricyclic antidepressants clomipramine and imipramine. The inhibition of cardiac Ca2+ and Na+ channels by fluoxetine may explain most cardiac side-effects observed occasionally with the drug and mild but significant bradycardia reported during chronic treatment. Our results suggest that fluoxetine and citalopram may have antiarrhythmic (class I + IV type), as well as proarrhythmic properties (due to impairment of atrioventricular or intraventricular conduction and shortening of repolarization). Taking all these into consideration, in depressed patients having also severe cardiac disorders, ECG control may be suggested during fluoxetine and probable another SSRI therapy. The primary goal of this review is to compare these direct cardiac effects of fluoxetine and citalopram to those of previously reported for TCAs. This paper also summarizes the recently observed effects of fluoxetine apparently not related to the blockage of 5-HT transporter based on literature.

Analysis of Deprenyl Metabolites in the Rat Brain Using HPLC-ES­ MS

Abstract:

Methylamphetamine and amphetamine, the two major metabolites of deprenyl in the rat brain were analyzed using HPLC method combined with electrospray-mass spectrometer. (-)-Deprenyl and (+)­ deprenyl were orally administered to rats either in a single dose of 10 mg/kg, or three times a week for three weeks. The metabolites were determined in four different parts of the rat brain, such as in the frontal cortex, corpus striatum, hippocampus, and hypophysis. The ratio of methylamphetamine to amphetamine was also compared after (-)-deprenyl and(+)­ deprenyl treatments.

Review of cardiovascular effects of fluoxetine, a selective serotonin reuptake inhibitor, compared to tricyclic antidepressants

Fluoxetine is an antidepressant drug, a potent and specific inhibitor of serotonin reuptake (SSRI). Evidence suggests that being compared with tricyclic antidepressants, fluoxetine may cause significantly fewer anticholinergic, antihistaminergic and cardiotoxic side effects in the treatment of major depressive disorders. Chronic treatment with fluoxetine was not reported to affect the electrocardiogram (ECG). There is no clinical evidence of conduction delay and very little evidence of orthostatic hypotension. In the overdosed patients fewer cardiac symptoms were reported than with tricyclic antidepressants. However, dysrhythmia (atrial fibrillation and bradycardia) and syncope associated with fluoxetine treatment and overdose were reported. Although such reports have not been common, they do raise concerns. Thus we investigated the direct cardiovascular effects of the fluoxetine in isolated heart preparations and vessels of rats and rabbits. From 10(-6)M to 10(-4)M concentrations fluoxetine showed cardiodepressant and vasodilatory effects. These effects were similar to those of previously reported on tricyclic compounds. This review is a brief summary of possible cardiovascular effects of fluoxetine and other new SSRIs antidepressants from the literature based on experience of clinical studies and our experiments with fluoxetine on isolated rat and rabbit cardiac preparations and vessels. Possible explanations of the lower incidence of cardiovascular complications with fluoxetine in humans and cardiodepressant effects in vitro are discussed.