Poststroke Treatment With Selective Serotonin Reuptake Inhibitors

Potential Role of Selective Serotonin Reuptake Inhibitors in Improving Functional Outcome after Stroke

The great advances in acute stroke treatment during the last decades have changed life after stroke considerably. However, the use of intravenous thrombolysis and endovascular thrombectomy is limited by a relatively narrow time window or contraindications for treatment. Further, patients receiving acute reperfusion therapies may still have cognitive and emotional complications due to underlying brain infarcts even though physical problems may almost disappear. Consequently, stroke is still a frequent cause of adult disability and death worldwide, and an effort to identify additional treatments to enhance recovery, preferably also feasible in the time after the acute phase, is warranted. Albeit several drugs and treatment modalities have been studied for their potential to enhance recovery after stroke, no treatment has unambiguously proven to potentiate the rehabilitation process. A promising candidate for pharmacological treatment is selective serotonin reuptake inhibitors (SSRIs), a group of commonly used antidepressants that may also possess neuro-regenerative properties. The current paper reviews the evidence for SSRIs as potential enhancers of stroke recovery and discusses the potential mechanisms behind the effects reported and the implications for the management of patients post-stoke, including potential adverse events and drug-drug interactions.

Early Selective Serotonin Reuptake Inhibitors for Recovery after Stroke: A Meta-Analysis and Trial Sequential Analysis

BACKGROUND

Potential benefits and risks of early (≤30 days from stroke onset) selective serotonin reuptake inhibitors (SSRIs) treatment for neurologic functional recovery after stroke are not fully understood.

METHODS

We searched PubMed, Embase, and the Cochrane Library to identify randomized controlled trials that assessed SSRI medications during the initial ictus after stroke versus placebo. Primary outcome was decrease in National Institutes of Health Stroke Scale (NIHSS) score. Secondary outcomes included the improvement of Barthel index, functional independence (modified Rankin Scale score 0-2 at the end of follow-up), the incidence of depression, and adverse events including diarrhea, insomnia, hepatic enzyme disorders, seizure, and intracranial hemorrhage. We used fixed effects models or random effects models to estimate weighted mean differences (WMDs) and relative risks (RRs) with 95% confidence intervals (CIs) according to heterogeneity.

RESULTS

Eight trials were included, with 1549 patients. Compared with placebo, decrease in NIHSS was greater in SSRI-treated patients (WMD, 0.82; 95% CI, 0.31-1.33; P = .002). Trial sequential analysis showed that the cumulative z curve crossed the trial sequential monitoring boundary for benefit, establishing sufficient and conclusive evidence. Early SSRI treatment also promoted Barthel index (WMD, 5.32; 95% CI, 1.65-8.99; P = .005) and functional independence (RR, 2.54; 95% CI, 1.82-3.55; P < .0001). There was no difference in the incidence of depression and adverse events between groups. No evidence of publication bias was detected.

CONCLUSIONS

The early SSRIs treatment reduces the defective neurologic function in patients undergoing rehabilitation after stroke.

Efficacy of Citalopram on Acute Ischemic Stroke Outcome: A Randomized Clinical Trial

BACKGROUND AND PURPOSE

Ischemic stroke (IS) is one of the main causes of death and disability in the adult population, and recovery from it is a major health concern worldwide. The aim of the present study was to evaluate the effectiveness of citalopram on 3-mounth outcome of nondepressed acute IS patients.

METHODS

In a randomized, placebo-controlled clinical trial, 144 patients with acute IS were studied for 3 months. In one group, the patients received oral citalopram 20 mg (once daily), and in the other group, they received placebo. All patients received standard care, including physiotherapy. Patients with depression were excluded throughout the study. The primary outcome of the study was set to a 50% reduction in the 3-month National Institutes of Health Stroke Scale compared with the baseline scores (Clinical Trial Registration URL: http://www.irct.ir ; Unique identifier: IRCT201203192150N2).

RESULTS

The mean age of patients was 66.4 years. Of 144 eligible patients, 15 patients died (4 in the citalopram and 11 in the placebo group), and 21 patients did not complete the study follow-up period (10 in the citalopram and 11 in the placebo group). The primary outcome of the study was achieved in 57 patients (79%) in the citalopram and 39 patients (54%) in the placebo group ( P < .001), with risk ratio and number needed to treat of 2 (CI = 1.2-3) and 4 (CI = 2.5-8.6), respectively. No major adverse events were found in either group.

CONCLUSIONS

Citalopram is a safe and tolerable medication in patients with acute IS, which could improve the outcome in these patients.

Partially Defective Store Operated Calcium Entry and Hem(ITAM) Signaling in Platelets of Serotonin Transporter Deficient Mice

BACKGROUND

Serotonin (5-hydroxytryptamin, 5-HT) is an indolamine platelet agonist, biochemically derived from tryptophan. 5-HT is secreted from the enterochromaffin cells into the gastrointestinal tract and blood. Blood 5-HT has been proposed to regulate hemostasis by acting as a vasoconstrictor and by triggering platelet signaling through 5-HT receptor 2A (5HTR2A). Although platelets do not synthetize 5-HT, they take 5-HT up from the blood and store it in their dense granules which are secreted upon platelet activation.

OBJECTIVE

To identify the molecular composite of the 5-HT uptake system in platelets and elucidate the role of platelet released 5-HT in thrombosis and ischemic stroke.

METHODS

5-HT transporter knockout mice (5Htt-/-) were analyzed in different in vitro and in vivo assays and in a model of ischemic stroke.

RESULTS

In 5Htt-/- platelets, 5-HT uptake from the blood was completely abolished and agonist-induced Ca2+ influx through store operated Ca2+ entry (SOCE), integrin activation, degranulation and aggregation responses to glycoprotein VI (GPVI) and C-type lectin-like receptor 2 (CLEC-2) were reduced. These observed in vitro defects in 5Htt-/- platelets could be normalized by the addition of exogenous 5-HT. Moreover, reduced 5-HT levels in the plasma, an increased bleeding time and the formation of unstable thrombi were observed ex vivo under flow and in vivo in the abdominal aorta and carotid artery of 5Htt-/- mice. Surprisingly, in the transient middle cerebral artery occlusion (tMCAO) model of ischemic stroke 5Htt-/- mice showed nearly normal infarct volume and the neurological outcome was comparable to control mice.

CONCLUSION

Although secreted platelet 5-HT does not appear to play a crucial role in the development of reperfusion injury after stroke, it is essential to amplify the second phase of platelet activation through SOCE and plays an important role in thrombus stabilization.