There are no obvious data to sustain that amisulpride-quetiapine-memantine association would induce remision of resistant schizophrenia. The clinical consequences and the challenge of medication for resistant schizophrenia are important. This case report brings additional information about therapy in resistant schizophrenia.

Case Report: 38 years old patient, male, with repeated hospitalizations for schizophreniaparanoid type, from 1989; the precedent psychotic episodes were treated with haloperidol, risperiodone,amisulpride, olanzapine, clozapine and quetiapine. The latest episode was treated with olanzapine (20mg/day- 8 weeks), with failure, and, after that, with clozapine (500mg/day- 8 weeks) without remission. The patient has been hospitalized after olanzapine and clozapine treatment failure and treated with association of two different classes of neuroleptics (amisulpride 800mg/day and quetiapine 200mg/day) and memantine (10mg/day).

The treatment with amisulpride-quetiapine- memantine association induced remission of symptoms and discharge from hospital after 18 days of treatment, sustained by PANSS score reduction (from105 at hospitalization to 40 at discharge). This symptoms remission is important because it happens after clozapine treatment failure, with known efficacy for treatment resistant schizophrenia.

For a patient with schizophrenia-paranoid type, treatment resistant, amisulpride-quetiapine- memantine association had the power to induce remission of symptoms. The combinated multireceptoral D2, 5HT2A, NMDA action of medication may be important in choosing the treatment for resistant schizophrenia.

Geriatric depression often presents with memory and cognitive complaints that are associated with increased risk for Alzheimer’s disease (AD). In a parent clinical trial of escitalopram combined with memantine or placebo for geriatric depression and subjective memory complaints, we found that memantine improved executive function and delayed recall performance at 12 months (NCT01902004). In this report, we used positron emission tomography (PET) to assess the relationship between in-vivo amyloid and tau brain biomarkers and clinical and cognitive treatment response.

In a randomized double-blind placebo-controlled trial, we measured 2-(1-{6-[(2-[F18]fluoroethyl)(methyl)amino]-2-naphthyl}ethylidene) malononitrile ([18F]FDDNP) binding at baseline and assessed mood and cognitive performance at baseline, posttreatment (6 months), and naturalistic follow-up (12 months).

Twenty-two older adults with major depressive disorder and subjective memory complaints completed PET scans and were included in this report.

Across both treatment groups, higher frontal lobe [18F]FDDNP binding at baseline was associated with improvement in executive function at 6 months (corrected p = .045). This effect was no longer significant at 12 months (corrected p = .12). There was no association of regional [18F]FDDNP binding with change in mood symptoms (corrected p = .2).

[18F]FDDNP binding may predict cognitive response to antidepressant treatment. Larger trials are required to further test the value of [18F]FDDNP binding as a biomarker for cognitive improvement with antidepressant treatment in geriatric depression.

Dysfunction of N-methyl-D-aspartate receptor (NMDAR) is involved in the pathophysiology of schizophrenia. A meta-analysis of randomized controlled trials (RCTs) was conducted to examine the efficacy and safety of memantine, a non-competitive NMDAR antagonist, in the treatment of schizophrenia.

Standardized/weighted mean differences (SMDs/WMDs), risk ratio (RR), and their 95% confidence intervals (CIs) were calculated and analyzed.

Included in the meta-analysis were eight RCTs (n = 452) of 11.5 ± 2.6 weeks duration, with 229 patients on memantine (20 mg/day) and 223 patients on placebo. Adjunctive memantine outperformed placebo in the measures of Positive and Negative Syndrome Scale and Brief Psychiatric Rating Scale negative symptoms [SMD: −0.63 (95% CI −1.10 to −0.16), p = 0.009, I2 = 77%], but not in the total, positive and general symptoms [SMD: −0.46 to −0.08 (95% CI −0.93 to 0.22), p = 0.06–0.60, I2 = 0–74%] or the Clinical Global Impression Severity Scale [WMD: 0.04 (95% CI −0.24 to 0.32), p = 0.78]. The negative symptoms remained significant after excluding one outlying RCT [SMD: −0.41 (95% CI −0.72 to −0.11), p = 0.008, I2 = 47%]. Compared with the placebo group, adjunctive memantine was associated with significant improvement in neurocognitive function using the Mini-Mental State Examination (MMSE) [WMD: 3.09, (95% CI 1.77–4.42), p < 0.00001, I2 = 22%]. There was no significant difference in the discontinuation rate [RR: 1.34 (95% CI 0.76–2.37), p = 0.31, I2 = 0%] and adverse drug reactions between the two groups.

This meta-analysis showed that adjunctive memantine appears to be an efficacious and safe treatment for improving negative symptoms and neurocognitive performance in schizophrenia. Higher quality RCTs with larger samples are warranted to confirm these findings.

In a recent placebo-controlled, double-blind crossover trial (n = 52), significant beneficial effects on memory (d = 0.30) and negative symptoms (d = 0.29) were found after 12 weeks of memantine augmentation in patients with clozapine-refractory schizophrenia. In this open-label 1-year extension study we report the long-term effects and tolerability of memantine add-on therapy to clozapine.

Completers of the first trial who experienced beneficial effects during 12 weeks of memantine treatment received memantine for 1 year. Primary endpoints were memory and executive function using the Cambridge Neuropsychological Test Automated Battery, the Positive and Negative Syndrome Scale (PANSS), and the Clinical Global Impression Severity Scale (CGI-S).

Of 31 randomized controlled trial completers who experienced beneficial effects from memantine, 24 received memantine for 1 year. The small improvement in memory found in the memantine condition in the placebo-controlled trial remained stable in the extension study. Executive function did not improve. After 26 weeks of memantine add-on therapy to clozapine, PANSS negative symptoms (r = 0.53), PANSS positive symptoms (r = 0.50) and PANSS total symptoms (r = 0.54) significantly improved. Even further significant improvement in all these measures was observed between 26 weeks and 52 weeks of memantine, with effect sizes varying from 0.39 to 0.51. CGI-S showed a non-significant moderate improvement at 26 weeks (r = 0.36) and 52 weeks (r = 0.34). Memantine was well tolerated without serious adverse effects.

In the 1-year extension phase the favourable effect of adjunctive memantine on memory was sustained and we observed further improvement of negative, positive and overall symptoms in patients with clozapine-treated refractory schizophrenia.

Dysfunction of neuroplasticity due to N-methyl-d-aspartate (NMDA) receptor hypofunction may be a causal factor for memory and executive dysfunctioning in schizophrenia. Deregulation of NMDA transmission in the prefrontal cortex may also explain negative and positive symptoms. Clozapine augmentation with memantine targets altered NMDA receptor-mediated neurotransmission in schizophrenia and showed substantial beneficial effects on several symptom domains in a small proof-of-concept study. We evaluate effects of memantine add-on treatment to clozapine for memory and executive function, and negative and positive symptoms in schizophrenia.

Clozapine-treated patients with refractory schizophrenia were randomly assigned to 12 weeks of double-blind adjunctive treatment with memantine (n = 26) or placebo (n = 26). Crossover occurred after a 2-week placebo wash-out period. Primary endpoints were change from baseline to 12 weeks treatment and 14 weeks to 26 weeks treatment on memory and executive function using the Cambridge Neuropsychological Test Automated Battery (CANTAB), Positive and Negative Syndrome Scale (PANSS), and Clinical Global Impression Severity Scale (CGI-S). Side effects were assessed using the Liverpool University Neuroleptic Side-Effect Rating Scale.

When compared with placebo, memantine improved a composite memory score comprising verbal recognition memory and paired associates learning task scores on the CANTAB (effect size = 0.30) and PANSS negative subscale score (effect size = 0.29). Side effects were mild and transient.

In patients with clozapine-treated refractory schizophrenia, memantine addition significantly improved verbal and visual memory and negative symptoms without serious adverse effects. These results justify further investigations on long-term memantine augmentation to clozapine in treatment-resistant schizophrenia.

Continuous treatment is an important indicator of medication adherence in dementia. However, long-term studies in larger clinical settings are lacking, and little is known about moderating effects of patient and service characteristics.

Data from 12,910 outpatients with dementia (mean age 79.2 years; SD = 7.6 years) treated between January 2003 and December 2013 in Germany were included. Continuous treatment was analysed using Kaplan–Meier curves and log-rank tests. In addition, multivariate Cox regression models were fitted with continuous treatment as dependent variable and the predictors antidementia agent, age, gender, medical comorbidities, physician specialty, and health insurance status.

After one year of follow-up, nearly 60% of patients continued drug treatment. Donezepil (HR: 0.88; 95% CI: 0.82–0.95) and memantine (HR: 0.85; 0.79–0.91) patients were less likely to be discontinued treatment as compared to rivastigmine users. Patients were less likely to be discontinued if they were treated by specialist physicians as compared to general practitioners (HR: 0.44; 0.41–0.48). Younger male patients and patients who had private health insurance had a lower discontinuation risk. Regarding comorbidity, patients were more likely to be continuously treated with the index substance if a diagnosis of heart failure or hypertension had been diagnosed at baseline.

Our results imply that besides type of antidementia agent, involvement of a specialist in the complex process of prescribing antidementia drugs can provide meaningful benefits to patients, in terms of more disease-specific and continuous treatment.

Pharmaceutical therapy for patients with dementia including cholinesterase inhibitors (ChEI) and memantine is covered by Taiwan's National Health Insurance (NHI) but with strict reimbursement criteria. This study compared utilization of selected cognitive enhancers among elderly patients with dementia and estimated associated differences in medical care costs.

This study used medical claims and pharmacy claims from the NHI Research Database of Taiwan from 2009 to 2011, which included all patients 65 years or older diagnosed with dementia in their outpatient or inpatient claims. Both individual-level and market-level analysis were performed to calculate the average medical costs per person and the share of drug expenditures. Generalized linear models with propensity score adjustment estimated differences in medical care costs by use of selected cognitive enhancers.

Users of ChEI had the highest medication and outpatient costs but the lowest inpatient costs among all users of cognitive enhancers. However, annual adjusted total medical care costs per ChEI user were not significantly different from those who used cerebral vasodilators (CBV). In 2011, 52.4% of the elderly with dementia in Taiwan used cognitive enhancers, but among them 88.3% used CBV while 9.2% used ChEI. Among patients with dementia who used at least one cognitive enhancer, the aggregated expenditure as a share of their total drug expenditures was 9.7% in 2011.

Given that CBV had a much higher utilization rate than ChEI or memantine among elderly people with dementia, the strict reimbursement policy for ChEI and memantine may need to be revisited to increase access to those drugs by patients with dementia in Taiwan.

Behavioural symptoms are common in moderate to severe Alzheimer's disease (AD) and are improved by memantine with the most pronounced effect on agitation/aggression. Dextromethorphan in combination with quinidine is the only drug approved by US Food and Drug Administration for the treatment of pseudobulbar affect (PBA) on the basis of efficacy in patients with multiple sclerosis or amyotrophic lateral sclerosis. The aim of our study was to evaluate the efficacy of memantine on PBA in patients with AD.

In a prospective, double-blind, case-control study to assess PBA with pathological laughter and crying scale patients were administered memantine (final dose of 20 mg daily) or citalopram (20 mg once daily), each for 10 weeks. The number of episodes of involuntary emotional expression, Neuropsychiatric Inventory (NPI) and Overt Aggression Scale-Modified (OAS-M) total scores were also recorded. Furthermore, the platelet serotonin (5-HT) concentration was measured.

Although memantine had beneficial effects on PBA, it also had a crucial impact on behavioural symptoms, especially aggression and agitation (to an average of 3.5 times higher end-point scores on OAS-M and increase of NPI total scores for an average of 114% of initial value). Therefore, the study was prematurely stopped. In addition, we had evidenced a drop of platelet 5-HT concentration (to an average of 73% of initial value).

Surprisingly, our research showed the opposite action of memantine on neuropsychiatric symptoms as expected. In a limited number of AD patients with PBA, memantine had a beneficial effect on involuntary emotional expression, but it potentiated agitation/aggression, irritability and caused a crucial drop of the platelet 5-HT concentration.

This study aimed to contribute to the literature on the prevention and treatment of ototoxicity due to various drugs and chemicals.

This study compared the histological effects of intratympanic dexamethasone, memantine and piracetam on cellular apoptosis due to cisplatin ototoxicity, in 36 rats.

Dexamethasone and memantine had significant effects on the stria vascularis, organ of Corti and spiral ganglion (p < 0.05). Although piracetam decreased the apoptosis rate, this effect was not statistically significant (p > 0.05).

Dexamethasone and memantine were found superior to piracetam in reducing apoptosis due to cisplatin ototoxicity. Further studies of this subject are needed, incorporating electron microscopy and auditory brainstem response testing.