Phase 1, placebo-controlled, single ascending dose trial to evaluate the safety, pharmacokinetics and effect on altered states of consciousness of intranasal BPL-003 (5-methoxy-N,N-dimethyltryptamine benzoate) in healthy participants.

AIMS: To investigate the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of BPL-003, a novel intranasal benzoate salt formulation of 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT), in healthy participants. METHODS: In all, 44 psychedelic-naïve participants enrolled in the double-blind, placebo-controlled single ascending dose study (1-12 mg BPL-003). Concentrations of 5-MeO-DMT and its pharmacologically active metabolite, bufotenine, were determined in plasma and urine. PD endpoints included subjective drug intensity (SDI) rating, the Mystical Experience Questionnaire (MEQ-30) and the Ego Dissolution Inventory (EDI). RESULTS: BPL-003 was well tolerated at doses up to 12 mg. There were no serious adverse events (AEs), and most AEs were mild; the most common being nasal discomfort, nausea, headache and vomiting. 5-MeO-DMT was rapidly absorbed and eliminated; the median time to peak plasma concentration was approximately 8-10 min and the mean terminal elimination half-life was <27 min. 5-MeO-DMT systemic exposure increased approximately dose-proportionally, while plasma bufotenine concentrations and urinary excretion of 5-MeO-DMT and bufotenine were negligible. The intensity of the SDI ratings was associated with plasma 5-MeO-DMT concentrations. MEQ-30 and EDI scores generally increased with the BPL-003 dose; 60% of participants had a 'complete mystical experience' at 10 and 12 mg doses. Profound and highly emotional consciousness-altering effects were observed with BPL-003, with a rapid onset and short-lasting duration. CONCLUSION: The novel intranasal formulation of BPL-003 was well tolerated with dose-proportional increases in PK and PD effects. The short duration of action and induction of mystical experiences suggest clinical potential, warranting further trials. CLINICAL TRIAL REGISTRATION: NCT05347849.

Effect of Sleep Disturbance on Efficacy of Esketamine in Treatment-Resistant Depression: Findings from Randomized Controlled Trials.

PURPOSE: To evaluate the relationship of sleep disturbance to the antidepressant effects of esketamine. MATERIALS AND METHODS: Two double-blind, 4-week studies randomized adults with treatment-resistant depression (TRD) to placebo or esketamine nasal spray, each with newly initiated antidepressant. Sleep was assessed using Montgomery-Åsberg Depression Rating Scale (MADRS) item 4. Change in response (≥50% decrease in MADRS total score) and remission (total MADRS score ≤12) at day 28 was examined by presence/absence of baseline sleep disturbance using logistic regression models. Impact on reported sleep disturbance (MADRS item 4 score) was examined using ANCOVA models. RESULTS: At baseline, most patients reported disturbed sleep - moderate/severe (65.3%, 369/565), mild (25.3%, 143/565), or none/slightly (9.4%, 53/565) - with similar distribution between treatment groups. A higher proportion of esketamine-treated patients achieved response (OR = 2.05; 95% CI: 1.40-3.02; P < 0.001) and remission (OR = 1.81; 95% CI: 1.23-2.66; P = 0.003) at day 28 compared to antidepressant plus placebo, regardless of presence/severity of sleep disturbance. Consistent with this, sleep (MADRS item 4 score) improved in both groups after the first dose, more so with esketamine by day 8 (between-group difference: P ≤ 0.02 at all time points). Across both treatment groups, 1-point improvement in sleep at day 8 increased the probability of antidepressant response on day 28 by 26% (OR = 1.26, 95% CI: 1.12-1.42; P < 0.001), and remission by 28% (OR = 1.28, 95% CI: 1.14-1.43; P < 0.001). CONCLUSION: Antidepressant efficacy of esketamine was demonstrated in patients with TRD, regardless of the presence of sleep disturbance. After 8 days of treatment and thereafter, significantly more esketamine-treated patients reported improvement in sleep versus antidepressant plus placebo.

Treatment patterns of patients diagnosed with major depressive disorder and suicidal ideation or attempt: a U.S. population-based study utilizing real-world data.

BACKGROUND: There is a knowledge gap regarding the treatment patterns of patients with major depressive disorder (MDD) who experience suicidal ideation or a suicide attempt (SI/SA). METHODS: Patients with SI/SA were identified from a large US-based claims database covering 84 million lives, during 1/1/2014-3/31/2020. Patients with MDD were indexed at their first diagnosis for SI/SA and followed up to 365 days. Treatment patterns were captured at the class level and included procedures of electroconvulsive therapy and transcranial magnetic stimulation, and pharmacotherapy including selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors, tricyclic antidepressants, other antidepressants, anxiolytics, hypnotics/sedatives, antipsychotics, psychostimulants, and lithium. RESULTS: There were 42,204 MDD + SI/SA patients identified. In the year prior to the index event > 40% of individuals received an SSRI and more than one-third received an anxiolytic. Within 1 year following, 84.4% received ≥1 of the treatments of interest. Of those, 70.2% went on to a subsequent class-based regimen, 46.3% received a third, and 28.1% received ≥4. More than three-quarters of patients received multiple treatment classes simultaneously. SSRIs were the most common treatments during follow-up (61.9%), followed by other antidepressants (51.3%), anxiolytics (50.8%) and anticonvulsants (43.6%). CONCLUSIONS: There was a large amount of variability and polypharmacy in the treatments received by MDD patients with SI/SA, and is much more complex than what has been previously observed in the general MDD population. Within one-year, many patients received four or more unique class-based regimens and most patients received treatments from multiple classes simultaneously, indicating the high unmet medical need and therapy refractoriness of this patient population.

Managing Esketamine Treatment Frequency Toward Successful Outcomes: Analysis of Phase 3 Data.

BACKGROUND: Esketamine nasal spray was recently approved for treatment-resistant depression. The current analysis evaluated the impact of symptom-based treatment frequency changes during esketamine treatment on clinical outcomes. METHODS: This is a post-hoc analysis of an open-label, long-term (up to 1 year) study of esketamine in patients with treatment-resistant depression (SUSTAIN 2). During a 4-week induction phase, 778 patients self-administered esketamine twice weekly plus a new oral antidepressant daily. In responders (≥50% reduction in Montgomery-Åsberg Depression Rating Scale total score from baseline), esketamine treatment frequency was thereafter decreased during an optimization/maintenance phase to weekly for 4 weeks and then adjusted to the lowest frequency (weekly or every other week) that maintained remission (Montgomery-Åsberg Depression Rating Scale ≤ 12) based on a study-defined algorithm. The relationship between treatment frequency and symptom response, based on clinically meaningful change in Clinical Global Impression-Severity score, was subsequently evaluated 4 weeks after treatment frequency adjustments in the optimization/maintenance phase. RESULTS: Among 580 responders treated with weekly esketamine for the first 4 weeks in the optimization/maintenance phase (per protocol), 26% continued to improve, 50% maintained clinical benefit, and 24% worsened. Thereafter, when treatment frequency could be reduced from weekly to every other week, 19% further improved, 49% maintained benefit, and 32% worsened. For patients no longer in remission after treatment frequency reduction, an increase (every other week to weekly) resulted in 47% improved, 43% remained unchanged, and 10% worsened. CONCLUSIONS: These findings support individualization of esketamine nasal spray treatment frequency to optimize treatment response in real-world clinical practice. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02497287.

Physicians in the pharmaceutical industry: their roles, motivations, and perspectives.

Although physicians occupy a significant number of key positions in the pharmaceutical industry, practicing clinicians are often unaware of the variety of career paths within this industry, or of the structure of a pharmaceutical company. Here, we address questions that practicing clinicians frequently ask their colleagues in the pharmaceutical industry. In addition to providing an overview of the common roles occupied by physicians in pharma, we also describe the various motivations for transitioning into the industry and discuss different scenarios regarding the timing of the career change. Furthermore, we outline the characteristics and skills that enable physicians to have a successful career in pharma.

Estimating Prevalence and Healthcare Utilization for Treatment-Resistant Depression in Japan: A Retrospective Claims Database Study.

BACKGROUND: Major depressive disorders (MDDs) including treatment-resistant depression (TRD) are common disabling conditions, but data on their epidemiology in Japan are limited. This study investigated the incidence, epidemiology, and direct medical costs of TRD and pharmaceutically-treated depression (PTD) in Japan to increase our health economic understanding of this phenotype of MDD. METHODS: A retrospective cohort study from a private health insurance claims database estimated the 1-year incidence of PTD and TRD and described the health services used and direct medical costs associated with these conditions. RESULTS: In the year from 1 April 2012 through 31 March 2013, we identified 1143 incident PTD cases among 98,552 eligible subjects, i.e. 11.59 cases/1000 patient-years. Of the PTD patients, 51.4% were women. Within the 1-year observation interval 137 patients failed more than two antidepressive treatment approaches and thus developed TRD. Though co-morbid conditions and age were similar among PTD and TRD patients, medical costs per patient (patient-year) during their treatment intervals were 1.01 million JPY (0. 540 million JPY) in the TRD population and 0.643 JPY million JPY (0.645 million JPY) in the PTD population who did not convert into TRD. CONCLUSIONS: This study describes the PTD and TRD patient populations in a large claims database in Japan and highlights an unmet medical need for the treatment of TRD to provide better preventative measures and interventions for the treatment of depression.

Intravenous Esketamine in Adult Treatment-Resistant Depression: A Double-Blind, Double-Randomization, Placebo-Controlled Study.

BACKGROUND: The purpose of this study was to assess the efficacy and safety and to explore the dose response of esketamine intravenous (IV) infusion in patients with treatment-resistant depression (TRD). METHODS: This multicenter, randomized, placebo-controlled trial was conducted in 30 patients with TRD. Patients were randomly assigned 1:1:1 to receive an IV infusion of .20 mg/kg or .40 mg/kg esketamine or placebo over 40 minutes on day 1. The primary end point was change in Montgomery-Åsberg Depression Rating Scale total score from day 1 (baseline) to day 2. Nonresponders who received placebo on day 1 were randomly assigned again 1:1 to IV esketamine .20 mg/kg or .40 mg/kg on day 4. Secondary efficacy and safety measures were also evaluated. RESULTS: Of the enrolled patients, 97% (29 of 30) completed the study. The least squares mean changes (SE) from baseline to day 2 in Montgomery-Åsberg Depression Rating Scale total score for the esketamine .20 mg/kg and .40 mg/kg dose groups were -16.8 (3.00) and -16.9 (2.61), respectively, and showed significant improvement (one-sided p = .001 for both groups) compared with placebo (-3.8 [2.97]). Esketamine showed a rapid (within 2 hours) and robust antidepressant effect. Treatment-emergent adverse events were dose dependent. The most common treatment-emergent adverse events were headache, nausea, and dissociation; the last-mentioned was transient and did not persist beyond 4 hours from the start of the esketamine infusion. CONCLUSIONS: A rapid onset of robust antidepressant effects was observed in patients with TRD after a 40-minute IV infusion of either .20 mg/kg or .40 mg/kg of esketamine. The lower dose may allow for better tolerability while maintaining efficacy.

Placebo response changes depending on the neuropathic pain syndrome: results of a systematic review and meta-analysis.

OBJECTIVE: To compare placebo responses in neuropathic pain syndromes. DESIGN: Systematic literature review and meta-analysis. SETTING AND PATIENTS: Randomized placebo-controlled trials assessing pain intensity or pain relief in any neuropathic pain syndrome published since 1995 with ≥5days follow-up. INTERVENTIONS: Placebo response. OUTCOME MEASURES: Pain intensity and responder rates (proportion reporting ≥50% pain relief). Meta-regression models were built. RESULTS: Ninety-four studies (N=5,317) were included in the pain intensity analysis; 47 studies (N=3,087) were included in the responder analysis. After controlling for potential confounders (e.g., subject characteristics, study design characteristics), the placebo response was found to be large and varied with the pain syndrome. Compared with diabetic neuropathic/polyneuropathic pain (DPN), the placebo response for a decline in pain intensity and responder rate was smaller in trials that assessed central pain and postherpetic neuralgia (PHN) and larger in trials that assessed HIV pain. The model-predicted mean decrease (95% confidence interval [CI]) from baseline in pain intensity (0-10 scale) was as follows: DPN, 1.45 (1.35 to 1.55); PHN, 1.16 (1.03 to 1.29); central pain, 0.44 (-0.41 to 1.30); HIV pain, 1.82 (1.51 to 2.12). The predicted responder rates (95% CI) were as follows: DPN, 20% (14.6 to 25.8); PHN, 11.5% (8.4 to 14.5); central pain, 7.2% (2.1 to 12.3); HIV pain, 42.8% (34.9 to 50.7). The type of treatment in the active arm also influenced the placebo response. CONCLUSIONS: Placebo response is influenced by the pain syndrome evaluated. These differences should be considered when evaluating novel compounds for the treatment of neuropathic pain conditions.

Population pharmacodynamic modeling of various extended-release formulations of methylphenidate in children with attention deficit hyperactivity disorder via meta-analysis.

Placebo and pharmacodynamic (PD) models were developed which link temporal measures of efficacy in children with attention deficit hyperactivity disorder (ADHD) and methylphenidate (MPH) plasma concentrations from adults. These models can be used to predict daily pediatric clinical measure profiles following administration of different MPH formulations in children without conducting pediatric pharmacokinetic (PK) or PD studies by using more easily obtained adult PK data. Mean PK data from various extended-release MPH formulations studied in adults and mean PD data from nine pediatric efficacy studies were obtained from the literature. The individual time-course of the clinical measures from three pediatric trials were also analyzed after being combined with the meta-analysis data. The clinical measure profiles following placebo administration were described by indirect response models with time-varying elimination rates. MPH pharmacodynamic effect was described by E(max) models, which included time-dependent tolerance. Internal and external evaluations using a visual predictive check technique confirmed the prediction capability of the models. This modeling exercise demonstrated that time courses of MPH concentrations in adults with different drug release patterns can be used to predict time courses of clinical efficacy parameters in pediatrics by employing the models developed by meta-analysis.

Cognitive effects of carisbamate in randomized, placebo-controlled, healthy-volunteer, multidose studies.

Adverse cognitive effects are an important concern for drugs that influence the central nervous system. Carisbamate is a novel drug in development for treatment of seizures and neuropathic pain. Information on its cognitive effects is limited. Three controlled, multiple-dose, crossover studies with treatment durations of 5-9 days were designed to examine the cognitive effects of carisbamate on healthy volunteers. In one study, apparent dose-dependent effects on response, vigilance, and recognition speed were observed (1000 mg and 1500 mg/day). Carisbamate did not differ from placebo for most variables in the other two studies, but increased reaction time and reduced Sternberg memory were seen at higher dosages. Carisbamate did not produce clinically significant adverse effects on cognitive performance at doses <1000 mg/day. Effects were mild to modest at the higher doses tested.

Efficacy, tolerability, and safety of rapid initiation of topiramate versus phenytoin in patients with new-onset epilepsy: a randomized double-blind clinical trial.

PURPOSE: To evaluate topiramate (TPM) and phenytoin (PHT) monotherapy following rapid oral initiation in new-onset epilepsy. METHODS: Randomized, double-blind, 28-day trial of TPM (100 mg/day beginning on day 1) versus PHT (1,000 mg on day 1 followed by 300 mg/day maintenance dosing) in 261 patients with new-onset epilepsy. The primary end point was time to seizure, and the primary objective was to establish noninferiority of TPM to PHT in the risk of seizure. RESULTS: At day 28, the estimated seizure-free rate was 81.1% for TPM treatment in comparison with 90.3% for PHT treatment. Noninferiority of TPM to PHT (primary objective) could not be established [hazard ratio (HR) 2.0, 95% confidence interval (CI), 0.98 to 4.12, p = 0.366), and PHT could not be shown to be superior to TPM. A higher percentage discontinued with PHT compared to TPM for all reasons (21.1 vs. 12.8%) and due to adverse events (13.4 vs. 6.8%). The most common treatment-related adverse events in both groups were dizziness, paresthesia, and somnolence. A post hoc analysis showed that TPM was superior to PHT in time to discontinuation (retention rate) for all causes (89.4% vs. 80.3%, p = 0.047). CONCLUSION: This study was inconclusive in establishing noninferiority of TPM 100 mg/day compared to a standard regimen of oral PHT in seizure risk in this population of patients with new-onset epilepsy. Given the superiority of TPM in overall retention and favorable tolerability without titration, it may nonetheless be an appropriate option in some patients with new-onset epilepsy requiring rapid treatment initiation.

Carisbamate in essential tremor: brief report of a proof of concept study.

The efficacy and safety of carisbamate, an investigational neuromodulator currently in development for epilepsy, were examined in a multicenter, randomized, double-blind, cross-over, placebo-controlled study of essential tremor. Sixty-two patients (intent-to-treat analysis set; mean age 64 years; 66% men) received carisbamate 400 mg/day or matching placebo in a crossover study design with two 21-day treatment periods. The Fahn-Tolosa-Marín Tremor Rating Scale (TRS) was the primary assessment tool. Carisbamate and placebo treatment did not differ in their effect on the TRS (P = 0.94) or on measures of affect, mood, or quality of life. Carisbamate was generally well tolerated and had an adverse event profile comparable to that of placebo.

A multicenter, outpatient, open-label study to evaluate the dosing, effectiveness, and safety of topiramate as monotherapy in the treatment of epilepsy in clinical practice.

This 24-week, multicenter, open-label trial was designed to evaluate the dosing, effectiveness, and safety of topiramate monotherapy for epilepsy and to identify patient and clinical characteristics predictive of optimally effective stabilized monotherapy doses. Of 406 randomized patients, 244 comprised the evaluable-for-efficacy population (12 weeks of treatment and stabilized topiramate dose during final 28 days); 213 were on topiramate monotherapy at the end of the trial. The mean stabilized daily dose of topiramate over the last 28 days of treatment (primary endpoint) was significantly lower for patients reporting one to three seizures (low seizure frequency, n=147) than for those reporting more than three seizures (high seizure frequency, n=66) during a 3-month retrospective baseline period (191 mg vs 239 mg, P=0.003). Patients in the low-seizure-frequency group reached a stable topiramate dose after a median of 36 days, compared with 53 days for patients in the high-seizure-frequency group. Linear and stepwise regression analyses showed baseline seizure frequency and lifetime seizure count to be significant (P<0.05) predictors of the stabilized dosage. Most treatment-emergent adverse events (TEAEs) were mild to moderate; those occurring with cumulative incidence rates >10% in either seizure frequency group were paresthesia, fatigue, anorexia, dizziness, somnolence, headache, and hypoesthesia; 18.2% of patients discontinued topiramate because of a TEAE, 5.1% reported serious TEAEs, and no deaths were reported during the study.

Improvement of physical health and quality of life of alcohol-dependent individuals with topiramate treatment: US multisite randomized controlled trial.

BACKGROUND: Topiramate can improve drinking outcomes via a hypothesized mechanism of facilitating gamma-aminobutyric acid function and inhibiting glutaminergic pathways in the corticomesolimbic system. We sought to determine whether topiramate's antidrinking effects are bolstered by improvements in physical and psychosocial well-being. METHODS: In a 17-site, 14-week, double-blind, randomized controlled trial, we compared the effects of topiramate (up to 300 mg/d) vs placebo on physical health, obsessional thoughts and compulsions about using alcohol, and psychosocial well-being among 371 alcohol-dependent subjects who received weekly adherence enhancement therapy. RESULTS: Topiramate was more efficacious than placebo in reducing body mass index (calculated as weight in kilograms divided by height in meters squared) (mean difference, 1.08; 95% confidence interval [CI], 0.81-1.34; P < .001), all liver enzyme levels (P < .01 for all comparisons), plasma cholesterol level (mean difference, 13.30 mg/dL; 95% CI, 5.09-21.44 mg/dL; P = .002), and systolic (mean difference, 9.70 mm Hg; 95% CI, 6.81-12.60 mm Hg; P < .001) and diastolic (mean difference, 6.74 mm Hg; 95% CI, 4.57-8.90 mm Hg; P < .001) blood pressure to about prehypertension levels-effects that might lower the risk of fatty liver degeneration and cirrhosis as well as cardiovascular disease. Topiramate compared with placebo significantly (P < .05 for all comparisons) decreased obsessional thoughts and compulsions about using alcohol, increased subjects' psychosocial well-being, and improved some aspects of quality of life, thereby diminishing the risk of relapse and longer-term negative outcomes. Paresthesia, taste perversion, anorexia, and difficulty with concentration were reported more frequently for topiramate than for placebo. CONCLUSION: Topiramate appears to be generally effective at improving the drinking outcomes and physical and psychosocial well-being of alcoholic subjects.

Topiramate for treating alcohol dependence: a randomized controlled trial.

CONTEXT: Hypothetically, topiramate can improve drinking outcomes among alcohol-dependent individuals by reducing alcohol's reinforcing effects through facilitation of gamma-aminobutyric acid function and inhibition of glutaminergic pathways in the corticomesolimbic system. OBJECTIVE: To determine if topiramate is a safe and efficacious treatment for alcohol dependence. DESIGN, SETTING, AND PARTICIPANTS: Double-blind, randomized, placebo-controlled, 14-week trial of 371 men and women aged 18 to 65 years diagnosed with alcohol dependence, conducted between January 27, 2004, and August 4, 2006, at 17 US sites. INTERVENTIONS: Up to 300 mg/d of topiramate (n = 183) or placebo (n = 188), along with a weekly compliance enhancement intervention. MAIN OUTCOME MEASURES: Primary efficacy variable was self-reported percentage of heavy drinking days. Secondary outcomes included other self-reported drinking measures (percentage of days abstinent and drinks per drinking day) along with the laboratory measure of alcohol consumption (plasma gamma-glutamyltransferase). RESULTS: Treating all dropouts as relapse to baseline, topiramate was more efficacious than placebo at reducing the percentage of heavy drinking days from baseline to week 14 (mean difference, 8.44%; 95% confidence interval, 3.07%-13.80%; P = .002). Prespecified mixed-model analysis also showed that topiramate compared with placebo decreased the percentage of heavy drinking days (mean difference, 16.19%; 95% confidence interval, 10.79%-21.60%; P < .001) and all other drinking outcomes (P < .001 for all comparisons). Adverse events that were more common with topiramate vs placebo, respectively, included paresthesia (50.8% vs 10.6%), taste perversion (23.0% vs 4.8%), anorexia (19.7% vs 6.9%), and difficulty with concentration (14.8% vs 3.2%). CONCLUSION: Topiramate is a promising treatment for alcohol dependence. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00210925.

Topiramate monotherapy in epilepsy and migraine prevention.

OBJECTIVES: The purposes of this review were to assess the efficacy of topiramate as monotherapy for epilepsy and migraine prevention, describe how it should be used, and give clinical advice on how to manage the practical aspects of dosing, titration, and possible adverse events in these 2 indications. METHODS: We searched the PubMed and BIOSIS databases using the key words topiramate, epilepsy, and migraine from the year 1987 onward, and subsequently focused the search on larger controlled trial studies of topiramate as monotherapy. RESULTS: Studies have evaluated the use of topiramate as monotherapy in the treatment of partial-onset and generalized seizures and in the prevention of migraine. In a randomized study, 75% of epilepsy patients treated with 400 mg/d topiramate remained seizure free at 1 year. Patients in the same study treated with a lower dose of topiramate (50 mg/d) also experienced notable seizure reductions, with 59% of patients free of seizures at 1 year. A comparison trial of topiramate (100 or 200 mg/d), valproate, and carbamazepine found that topiramate was associated with a similar time to first posttreatment seizure as the other 2 agents (P = NS). Trials of topiramate monotherapy in migraine prevention found that 100 mg/d was associated with a > or =50% reduction in monthly migraine frequency in 49% to 54% of patients. The migraine prevention trials typically used a starting dose of 25 mg/d, with weekly increases of 25 mg and an initial monotherapy target dose of 100 mg/d. The most common adverse events associated with topiramate are paresthesia, weight loss, and other centrally mediated symptoms, many of which may be ameliorated by proper titration and dosing and by good communication between physician and patient. CONCLUSIONS: Data from controlled trials suggest that 100 mg/d topiramate as monotherapy is effective in the treatment of partial-onset and generalized seizures and in the prevention of migraine.

Serial analysis of gene expression identifies metallothionein-II as major neuroprotective gene in mouse focal cerebral ischemia.

We applied serial analysis of gene expression (SAGE) to study differentially expressed genes in mouse brain 14 hr after the induction of focal cerebral ischemia. Analysis of >60,000 transcripts revealed 83 upregulated and 94 downregulated transcripts (more than or equal to eightfold). Reproducibility was demonstrated by performing SAGE in duplicate on the same starting material. Metallothionein-II (MT-II) was the most significantly upregulated transcript in the ischemic hemisphere. MT-I and MT-II are assumed to be induced by metals, glucocorticoids, and inflammatory signals in a coordinated manner, yet their function remains elusive. Upregulation of both MT-I and MT-II was confirmed by Northern blotting. MT-I and MT-II mRNA expression increased as early as 2 hr after 2 hr of transient ischemia, with a maximum after 16 hr. Western blotting and immunohistochemistry revealed MT-I/-II upregulation in the ischemic hemisphere, whereas double labeling demonstrated the colocalization of MT with markers for astrocytes as well as for monocytes/macrophages. MT-I- and MT-II-deficient mice developed approximately threefold larger infarcts than wild-type mice and a significantly worse neurological outcome. For the first time we make available a comprehensive data set on brain ischemic gene expression and underscore the important protective role of metallothioneins in ischemic damage of the brain. Our results demonstrate the usefulness of SAGE to screen functionally relevant genes and the power of knock-out models in linking function to expression data generated by high throughput techniques.