The clomethiazole acute stroke study in ischemic, hemorrhagic, and t-PA treated stroke: Design of a phase III trial in the united states and canada

Gamma aminobutyric acid (GABA) receptor agonists for acute stroke

BACKGROUND

Gamma aminobutyric acid (GABA) receptor agonists have been shown to have a neuroprotectant effect in reducing infarct size and improving functional outcome in animal models of cerebrovascular disease. However, the sedative effects of GABA receptor agonists have limited their wider application in people with acute stroke, due to the potential risk of stupor. This is an update of a Cochrane Review first published in 2013, and previously updated in 2014 and 2016.

OBJECTIVES

To determine the efficacy and safety of GABA receptor agonists in the treatment of acute stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (accessed May 2018), the Cochrane Central Register of Controlled Trials (CENTRAL) 2018, Issue 4 (accessed May 2018), MEDLINE (from 1949 to May 2018), Embase (from 1980 to May 2018), CINAHL (from 1982 to May 2018), AMED (from 1985 to May 2018), and 11 Chinese databases (accessed May 2018). In an effort to identify further published, unpublished, and ongoing trials we searched ongoing trial registers, reference lists, and relevant conference proceedings, and contacted authors and pharmaceutical companies.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) investigating GABA receptor agonists versus placebo for people with acute stroke (within 12 hours after stroke onset), with the primary outcomes of efficacy and safety.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the titles and abstracts of identified records, selected studies for inclusion, extracted eligible data, cross-checked the data for accuracy, and assessed the risk of bias. We used the GRADE approach to assess the quality of the evidence.

MAIN RESULTS

We included five trials with 3838 participants (acute ischemic or hemorrhagic stroke patients, 3758 analyzed). Most of the participants recruited had acute ischaemic stroke, with limited data available from participants with other stroke subtypes, including total anterior circulation syndrome (TACS). The methodological quality of the included trials was generally good, with an unclear risk for selection bias only. For death and dependency at three months, pooled results did not find a significant difference for chlormethiazole versus placebo (risk ratio (RR) 1.03, 95% confidence interval (CI) 0.96 to 1.11; four trials; 2909 participants; moderate-quality evidence) and for diazepam versus placebo (RR 0.94, 95% CI 0.82 to 1.07; one trial; 849 participants; moderate-quality evidence). The most frequent adverse events related to chlormethiazole were somnolence (RR 4.56, 95% CI 3.50 to 5.95; two trials; 2527 participants; moderate-quality evidence) and rhinitis (RR 4.75, 95% CI 2.67 to 8.46; two trials; 2527 participants; moderate-quality evidence).

AUTHORS' CONCLUSIONS

This review provides moderate-quality evidence that fails to support the use of GABA receptor agonists (chlormethiazole or diazepam) for the treatment of people with acute stroke. More well-designed RCTs with large samples of participants with total anterior circulation syndrome are required to determine if there are benefits for this subgroup. Somnolence and rhinitis are frequent adverse events related to chlormethiazole.

Gamma aminobutyric acid (GABA) receptor agonists for acute stroke

BACKGROUND

Gamma aminobutyric acid (GABA) receptor agonists have been shown to have a neuroprotectant effect in reducing infarct size and improving functional outcome in animal models of cerebrovascular disease. However, the sedative effects of GABA receptor agonists have limited their wider application in people with acute stroke, due to the potential risk of stupor. This is an update of a Cochrane review first published in 2013, and previously updated in 2014.

OBJECTIVES

To determine the efficacy and safety of GABA receptor agonists in the treatment of acute stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (accessed March 2016), the Cochrane Central Register of Controlled Trials (CENTRAL) 2016, Issue 3, part of the Cochrane Library (accessed March 2016), MEDLINE (from 1949 to March 2016), Embase (from 1980 to March 2016), CINAHL (from 1982 to March 2016), AMED (from 1985 to March 2016), and 11 Chinese databases (accessed March 2016). In an effort to identify further published, unpublished, and ongoing trials we searched ongoing trials registers, reference lists, and relevant conference proceedings, and contacted authors and pharmaceutical companies.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) investigating GABA receptor agonists versus placebo for people with acute stroke (within 12 hours after stroke onset), with the primary outcomes of efficacy and safety.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the titles and abstracts of identified records, selected studies for inclusion, extracted eligible data, cross-checked the data for accuracy, and assessed the risk of bias.

MAIN RESULTS

We included five trials with 3838 participants (3758 analyzed). The methodological quality of the included trials was generally good, with an unclear risk for selection bias only. Four trials (N = 2909) measured death and dependency at three months for chlormethiazole versus placebo; pooled results did not find a significant difference (risk ratio (RR) 1.03, 95% confidence interval (CI) 0.96 to 1.11). One trial (N = 849) measured this outcome for diazepam versus placebo (RR 0.94, 95% CI 0.82 to 1.07). The most frequent adverse events related to chlormethiazole were somnolence (RR 4.56, 95% CI 3.50 to 5.95; two trials; N = 2527) and rhinitis (RR 4.75, 95% CI 2.67 to 8.46; two trials; N = 2527).

AUTHORS' CONCLUSIONS

This review provides moderate-quality evidence that fails to support the use of GABA receptor agonists (chlormethiazole or diazepam) for the treatment of people with acute stroke. More well-designed RCTs with large samples of participants with total anterior circulation syndrome are required to determine if there are benefits for this subgroup. Somnolence and rhinitis are frequent adverse events related to chlormethiazole.

Developing drug strategies for the neuroprotective treatment of acute ischemic stroke

Developing new treatment strategies for acute ischemic stroke in the last twenty years has offered some important successes, but also several failures. Most trials of neuroprotective therapies have been uniformly negative to date. Recent research has reported how excitatory amino acids act as the major excitatory neurotransmitters in the cerebral cortex and hippocampus. Furthermore, other therapeutic targets such as free radical scavenger strategies and the anti-inflammatory neuroprotective strategy have been evaluated with conflicting data in animal models and human subjects with acute ischemic stroke. Whereas promising combinations of neuroprotection and neurorecovery, such as citicoline, albumin and cerebrolysin have been tested with findings worthy of further evaluation in larger randomized clinical trials. Understanding the complexities of the ischemic cascade is essential to developing pharmacological targets for acute ischemic stroke in neuroprotective or flow restoration therapeutic strategies.

Gamma aminobutyric acid (GABA) receptor agonists for acute stroke

BACKGROUND

Gamma aminobutyric acid (GABA) receptor agonists have been shown to have a neuroprotectant effect in reducing infarct size and improving functional outcome in animal models of cerebral ischemia. However, the sedation effects of GABA receptor agonists have limited their wider application in acute stroke patients due to the potential risk of stupor.

OBJECTIVES

To determine the efficacy and safety of GABA receptor agonists in the treatment of acute stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (February 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 5), MEDLINE (1949 to June 2014), EMBASE (1980 to June 2014), CINAHL (1982 to June 2014), AMED (1985 to June 2014) and 11 Chinese databases (June 2014). In an effort to identify further published, unpublished and ongoing trials we searched ongoing trials registers, reference lists and relevant conference proceedings, and contacted authors and pharmaceutical companies.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) investigating GABA receptor agonists versus placebo for acute stroke patients (within 12 hours after stroke onset), with the outcomes of death or dependency, functional independence and adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the titles and abstracts of identified records, selected studies for inclusion, extracted eligible data, cross-checked the data for accuracy and assessed the methodological quality.

MAIN RESULTS

We included five trials with 3838 patients. The methodological quality of the included trials was generally good, with low risk of bias. Four trials measured death and dependency at three months in chlormethiazole versus placebo without significant difference (risk ratio (RR) 1.03, 95% confidence interval (CI) 0.95 to 1.11). One trial measured this outcome between diazepam and placebo (RR 0.94, 95% CI 0.82 to 1.07). In the subgroup analysis of total anterior circulation syndrome (TACS), a higher percentage of functional independence was found in the chlormethiazole group (RR 1.33, 95% CI 1.09 to 1.64). The frequent adverse events related to chlormethiazole were somnolence (RR 4.56, 95% CI 3.50 to 5.95) and rhinitis (RR 4.75, 95% CI 2.67 to 8.46).

AUTHORS' CONCLUSIONS

This review does not provide the evidence to support the use of GABA receptor agonists (chlormethiazole or diazepam) for the treatment of patients with acute ischemic or hemorrhagic stroke. Chlormethiazole appeared to be beneficial in improving functional independence in patients with TACS according to the subgroup analysis, but this result must be interpreted with great caution. More well-designed RCTs with large samples of TACS would be required for further confirmation. However, somnolence and rhinitis are frequent adverse events related to chlormethiazole.

The clomethiazole acute stroke study (CLASS): Safety results in 1,356 patients with acute hemispheric stroke

The Clomethiazole Acute Stroke Study (CLASS) showed no difference in outcome between patients treated with clomethiazole or placebo for all patients treated, but a beneficial effect in patients classified as a total anterior circulation syndrome (TACS). These are patients with clinical symptoms of a large stroke. Safety and tolerability data are reported here with emphasis on the safety of treating stroke patients with a sedative drug. In total, 1,356 patients were eligible for safety analysis. Mortality at 90 days was equal between the treatment groups (clomethiazole, 19.5%; placebo, 19.7%). Clomethiazole was generally well-tolerated. The most common adverse event was sedation (clomethiazole, 53%; placebo, 10%). Clomethiazole also produced some respiratory adverse events (e.g., rhinitis and increased sputum). Serious adverse events associated with sedation were more commonly reported in the clomethiazole group during treatment. However, the incidence was low. There was no difference in the incidence of serious adverse events between the treatment groups for pulmonary conditions, cardiovascular conditions, or other conditions. Clomethiazole produced a small decrease in blood pressure, but this was not associated with a worse outcome. Safety and tolerability in TACS patients was similar to that for all patients treated with the exception that these patients were more sensitive to the sedative effects of the drug. Despite this, mortality was slightly lower, and functional outcome was better in clomethiazole-treated TACS patients compared with placebo. In conclusion, clomethiazole was generally well-tolerated. The sedation observed did not increase the risk for complications, such as pulmonary serious adverse events or affect the outcome in a negative way. Clomethiazole appeared to be safe to use in stroke patients in general and in patients with a large stroke. The efficacy and safety in large strokes will be studied further in a new study, which is ongoing.

Gamma aminobutyric acid (GABA) receptor agonists for acute stroke

BACKGROUND

Gamma aminobutyric acid (GABA) receptor agonists have been shown to have a neuroprotectant effect in reducing infarct size and improving functional outcome in animal models of cerebral ischemia. However, the sedation effects of GABA receptor agonists have limited their wider application in acute stroke patients due to the potential risk of stupor.

OBJECTIVES

To determine the efficacy and safety of GABA receptor agonists in the treatment of acute stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (January 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 1), MEDLINE (1949 to March 2012), EMBASE (1980 to March 2012), CINAHL (1982 to March 2012), AMED (1985 to March 2012) and 11 Chinese databases (March 2012). In an effort to identify further published, unpublished and ongoing trials we searched ongoing trials registers, reference lists and relevant conference proceedings, and contacted authors and pharmaceutical companies.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) investigating GABA receptor agonists versus placebo for acute stroke patients (within 12 hours after stroke onset), with the outcomes of death or dependency, functional independence and adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the titles and abstracts of identified records, selected studies for inclusion, extracted eligible data, cross-checked the data for accuracy and assessed the methodological quality.

MAIN RESULTS

We included five trials with 3838 patients. The methodological quality of the included trials was generally good, with low risk of bias. Four trials measured death and dependency at three months in chlormethiazole versus placebo without significant difference (risk ratio (RR) 1.03, 95% confidence interval (CI) 0.95 to 1.11). One trial measured this outcome between diazepam and placebo (RR 0.94, 95% CI 0.82 to 1.07). In the subgroup analysis of total anterior circulation syndrome (TACS), a higher percentage of functional independence was found in the chlormethiazole group (RR 1.33, 95% CI 1.09 to 1.64). The frequent adverse events related to chlormethiazole were somnolence (RR 4.56, 95% CI 3.50 to 5.95) and rhinitis (RR 4.75, 95% CI 2.67 to 8.46).

AUTHORS' CONCLUSIONS

This review does not provide the evidence to support the use of GABA receptor agonists (chlormethiazole or diazepam) for the treatment of patients with acute ischemic or hemorrhagic stroke. Chlormethiazole appeared to be beneficial in improving functional independence in patients with TACS according to the subgroup analysis, but this result must be interpreted with great caution. More well-designed RCTs with large samples of TACS would be required for further confirmation. However, somnolence and rhinitis are frequent adverse events related to chlormethiazole.

Thrombolytic therapy for acute ischemic stroke: 3 h and beyond

The current status of thrombolytic therapy approved by the US Food and Drug Administration is intravenous recombinant plasminogen activator given within 3 h of the onset of ischemic stroke. Intra-arterial therapy is possible for up to 6 h but is not Food and Drug Administration-approved for this purpose. Based on current radiologic methods (i.e., magnetic resonance imaging and perfusion computed tomography scans), it is being increasingly realized that the time window for effective thrombolytic therapy is variable, and salvageable tissue in the form of the ischemic penumbra may exist for longer periods of time and could therefore offer a greater time window based on these imaging studies. Development of an effective neuroprotective drug would greatly enhance the stability of the penumbra and offer further opportunities for extending the time window for reperfusion.

Validation of the Oxfordshire Community Stroke Project syndrome diagnosis derived from a standard symptom list in acute stroke

BACKGROUND

The Oxfordshire Community Stroke Project (OCSP) classification allows distinction of stroke subtypes with different prognosis. OCSP classification inferred from clinical signs filled out on patient entry forms has been used to facilitate subgroup analysis in clinical trials. However, such procedure has not been validated against clinical diagnosis. In preparation for an acute stroke trial, we set out to perform such a validation.

METHODS

An OCSP syndrome diagnosis of 194 acute stroke patients in four hospitals was made within 24 h using a standard list with neurological signs, to be filled out by a stroke physician or neurological resident on duty. This was compared with OCSP diagnosis within 2 days of stroke onset by a (blinded) stroke neurologist ("gold standard").

RESULTS

The proportion of the OCSP syndromes was quite similar between standard list and clinical judgement. Sensitivity, specificity, positive and negative predictive values were respectively: LACS: 0.76, 0.88, 0.72, 0.90; TACS: 0.63, 0.93, 0.62, 0.88; PACS: 0.62, 0.76, 0.63, 0.75; POCS: 0.50, 0.98, 0.60, 0.97. Kappa for agreement was 0.63 (LACS), 0.37 (PACS), 0.50 (TACS). Neuro-imaging falsified stroke subtype diagnosis in 40 cases (20.6%) diagnosed using the standard list, and 42 (21.6%) diagnosed by stroke neurologists.

CONCLUSION

A standard list-derived stroke syndrome diagnosis may be used as a clinical test to make an OCSP syndrome diagnosis in acute stroke. The use of such list in acute stroke trials may facilitate uniformity in early stroke subtype diagnosis. However, to increase such uniformity, ancillary methods such as acute MRI should be evaluated.

Pharmacokinetics and sedative effects in healthy subjects and subjects with impaired liver function after continuous infusion of clomethiazole

OBJECTIVE

Clomethiazole is virtually completely eliminated by hepatic metabolism. This study was designed to assess the impact of liver impairment on its elimination and sedative effects.

METHODS

Eight patients with mild liver impairment (Child-Pugh grade A), eight patients with moderate/severe liver impairment (Child-Pugh grade B/C) and eight healthy subjects of similar age were given 68 mg/kg clomethiazole edisilate according to a 24-h infusion scheme aimed at producing minimum sedation as it was intended for clinical use in patients with stroke. Concentrations of clomethiazole and its active alpha-carbon hydroxylated metabolite NLA-715 were followed in plasma and urine for 96 h and 24 h, respectively. Sedation was monitored using a scale from 1 to 6.

RESULTS

The fraction excreted unchanged in urine was less than 0.2% for clomethiazole and less than 0.4% for NLA-715. Urine concentrations of clomethiazole were strongly correlated (r(2)=0.60) to plasma concentrations and approximately equal to unbound plasma concentrations. Plasma levels of NLA-715 increased steadily during the infusion, eventually reaching mean levels exceeding those of clomethiazole in all groups. Plasma clearance of clomethiazole in subjects with mildly impaired liver function was not statistically different from that of healthy controls (40 l/h vs 44 l/h). In subjects with moderate/severe liver impairment, there was a 50% reduction in clearance. Sedation was not observed except in two subjects in the Child-Pugh A group showing mild sedation.

CONCLUSION

The reduced clomethiazole clearance in patients with moderate/severe liver impairment seems to call for a reduction of clomethiazole dosage. However, sedation was not observed in this group at the investigated dose level.

Current intracerebral haemorrhage management

Primary intracerebral haemorrhage (ICH) refers to spontaneous bleeding from intraparenchymal vessels. It accounts for 10-20% of all strokes, with higher incidence rates amongst African and Asian populations. The major risk factors are hypertension and age. In addition to focal neurological findings, patients may present with symptoms of elevated intracranial pressure. The diagnosis of ICH can only be made through neuro-imaging. A CT scan is presently standard, although MRI is increasingly important in the evaluation of acute cerebrovascular disease. A significant proportion of intracerebral haematomas expand in the first hours post-ictus and this is often associated with clinical worsening. There is evidence that the peri-haematomal region is compromised in ICH. This tissue is oedematous, although the precise pathogenesis is controversial. An association between elevated arterial pressure and haematoma expansion has been reported. Although current guidelines recommend conservative management of arterial pressure in ICH, an acute blood pressure lowering trial is overdue. ICH is associated with a high early mortality rate, although a significant number of survivors make a functional recovery. Current medical management is primarily aimed at prevention of complications including pneumonia and peripheral venous thromboembolism. Elevated intracranial pressure may be treated medically or surgically. Although the latter definitively lowers elevated intracranial pressure, the optimal patient selection criteria are not clear. Aggressive treatment of hypertension is essential in the primary and secondary prevention of ICH.

Clomethiazole Acute Stroke Study in ischemic stroke (CLASS-I): final results

BACKGROUND AND PURPOSE

A previous trial (the Clomethiazole Acute Stroke Study) generated the hypothesis that clomethiazole is effective in patients with a major ischemic stroke (total anterior circulation syndrome), and this was tested in the present study.

METHODS

A total of 1198 patients with major ischemic stroke and a combination of limb weakness, higher cortical dysfunction, and visual field deficits were randomly assigned to clomethiazole (68 mg/kg IV over 24 hours) or placebo. The study drug was initiated within 12 hours of symptom onset. Functional outcome and neurological recovery were assessed at days 7, 30, and 90, with the proportion of patients with a Barthel Index > or =60 at last follow-up as the primary outcome measure.

RESULTS

The patients were randomly assigned equally, and the two treatment groups were well matched for baseline characteristics, including stroke severity (mean National Institutes of Health Stroke Scale score 16.9+/-5.2). Ninety-six percent were classified as total anterior circulation syndrome. The proportion of patients reaching a Barthel Index score of > or =60 was 42% in the clomethiazole-treated group and 46% in the placebo-treated group (odds ratio, 0.81; 95% CI, 0.62 to 1.05; P=0.11). There was no evidence of efficacy on any secondary outcome variables (modified Rankin Score, National Institutes of Health Stroke Scale, Scandinavian Stroke Scale, and 30-day CT infarct volumes) compared with placebo. Subgroup analysis showed a similar lack of treatment effect in patients treated early (<6 hours) and in those treated later (6 to 12 hours). Somnolence was an expected pharmacological effect of clomethiazole, and this occurred during treatment as an adverse event in half of the patients randomly assigned to study drug.

CONCLUSIONS

The target population was selected, and sufficient drug was given to produce the expected pharmacological effect in the brain. Clomethiazole does not improve outcome in patients with major ischemic stroke.

Poor prognosis of acute stroke patients denied thrombolysis due to early CT findings

OBJECTIVES

Whether acute stroke patients with major early infarct signs on computed tomography (CT) should be treated with intravenous (i.v.) thrombolysis remains controversial. The authors sought to define the outcomes in 5 consecutive patients who were not treated with i.v. thrombolysis, according to established guidelines.

METHODS

The authors retrospectively analyzed the outcomes of a consecutive series of 5 patients evaluated by an acute stroke team at a university medical center and who were denied i.v. tissue plasminogen activator due to early CT changes.

RESULTS

Five patients with a median National Institutes of Health Stroke Scale score of 22 (range 20-28) were evaluated. Despite aggressive care (e.g., hemicraniectomy), 2 patients died owing to herniation, 1 patient died of cardiac causes, and neither of the 2 surviving patients achieved a 3-month Rankin score below 4 (moderately severe disability).

CONCLUSIONS

Given the poor prognosis of patients with hemispheric stroke and early CT changes, alternative treatment modalities such as intra-arterial thrombolysis, early hemicraniectomy, and neuroprotective therapy should be vigorously pursued.

Results in 95 hemorrhagic stroke patients included in CLASS, a controlled trial of clomethiazole versus placebo in acute stroke patients

BACKGROUND AND PURPOSE

Clomethiazole is a neuroprotective drug that enhances gamma-aminobutyrate type A (GABA(A)) receptor activity. Its efficacy and safety were tested in the CLomethiazole Acute Stroke Study (CLASS). The protocol allowed a CT scan to be done after randomization but within 7 days of stroke onset to minimize delays before start of treatment. Ninety-five of the 1360 patients randomized were diagnosed as having intracranial hemorrhage rather than ischemic stroke. Safety results for clomethiazole compared with placebo in this group are reported.

METHODS

The study included patients with a clinical diagnosis of acute hemispheric cerebral infarction. Treatment was a 24-hour intravenous infusion of 75 mg/kg clomethiazole or placebo. Patients with intracranial hemorrhage discovered on a postrandomization CT were withdrawn from study treatment if treatment was ongoing, and all patients were followed up to 90 days.

RESULTS

Ninety-four patients received treatment, 47 in each group. The hemorrhage was classified as intracerebral in 89 patients (94%). Mortality at 90 days was 19.1% in the clomethiazole group and 23.4% in the placebo group. Sedation was the most common adverse event, occurring at a higher incidence in clomethiazole-treated patients (clomethiazole 53%, placebo 17%), followed by rhinitis and coughing. The incidence and pattern of serious adverse events was similar between the treatment groups. The percentage of patients reaching relative functional independence on the Barthel Index (score >/=60) at 90 days was 59.6% in the clomethiazole group and 53.2% in the placebo group.

CONCLUSIONS

Clomethiazole appears safe to administer to hemorrhagic stroke patients compared with placebo. These results would obviate the need for a CT scan before therapy is initiated in acute stroke. The safety of clomethiazole in hemorrhagic stroke patients will be further evaluated in a prospective study that is under way in North America.

The clomethiazole acute stroke study (CLASS): Efficacy results in 545 patients classified as total anterior circulation syndrome (TACS)

The CLASS study showed no significant difference between treatment groups for the neuroprotectant clomethiazole compared with placebo. However, a beneficial effect of the drug was seen in patients with total anterior circulation syndrome (TACS). These are patients with clinical symptoms suggesting a large stroke. Full results of this subgroup analysis are reported. Patients were classified before randomization using clinical symptoms into the stroke syndromes TACS, partial anterior circulation syndrome, and lacunar syndrome. Subgroup analyses of stroke syndromes were performed post hoc after detecting a treatment by severity interaction. The primary efficacy variable was relative functional independence defined as the proportion of patients scoring > or =60 on the Barthel Index at 90 days. TACS patients (n=546, 40% of all CLASS patients) were more severe at baseline on the 58 point Scandinavian Stroke Scale compared with non-TACS patients (median difference 10 points, mean difference 10.9 points, SE=0.6). Outcome for TACS patients treated with placebo was poor, with only 29.8% reaching relative functional independence. This was increased to 40.8% in the clomethiazole group, a 37% relative benefit, which is clinically significant (odds ratio=1.62, 95% CI 1.13-2.31, nominal P=.008). There was little or no difference in the outcome of non-TACS patients treated with clomethiazole compared with placebo. The treatment effect in TACS patients was quite consistent across participating countries and the 3 parts of the study defined by the 2 interim analyses. The treatment effect seen in patients with clinical symptoms suggesting a large stroke (TACS) is biologically plausible but requires confirmation in a prospective study which is ongoing.