Does the imbalance in the apolipoprotein E isoforms underlie the pathophysiological process of sporadic Alzheimer's disease?

Human apolipoprotein E (apoE) is a 299-amino acid secreted glycoprotein binding cholesterol and phospholipids, and with three common isoforms (APOE ε2, APOE ε3, and APOE ε4). The exact mechanism by which APOE gene variants increase/decrease Alzheimer's disease (AD) risk is not fully understood, but APOE isoforms differently affect brain homeostasis and neuroinflammation, blood-brain barrier (BBB) permeability, glial function, synaptogenesis, oral/gut microbiota, neural networks, amyloid beta (Aß) deposition, and tau-mediated neurodegeneration. In this perspective, we propose a comprehensive interpretation of APOE-mediated effects within AD pathophysiology, describing some specific cellular, biochemical, and epigenetic mechanisms and updating the different APOE-targeting approaches being developed as potential AD therapies. Intracisternal adeno-associated viral-mediated delivery of APOE ε2 is being tested in AD APOE ε4/ε4 carriers, while APOE mimetics are being used in subjects with perioperative neurocognitive disorders. Other approaches including APOE ε4 antisense oligonucleotides, anti-APOE ε4 monoclonal antibodies, APOE ε4 structure correctors, and APOE-Aß interaction inhibitors produced positive results in transgenic AD mouse models.

Genome-wide association identifies the first risk loci for psychosis in Alzheimer disease.

Psychotic symptoms, defined as the occurrence of delusions or hallucinations, are frequent in Alzheimer disease (AD with psychosis, AD + P). AD + P affects ~50% of individuals with AD, identifies a subgroup with poor outcomes, and is associated with a greater degree of cognitive impairment and depressive symptoms, compared to subjects without psychosis (AD - P). Although the estimated heritability of AD + P is 61%, genetic sources of risk are unknown. We report a genome-wide meta-analysis of 12,317 AD subjects, 5445 AD + P. Results showed common genetic variation accounted for a significant portion of heritability. Two loci, one in ENPP6 (rs9994623, O.R. (95%CI) 1.16 (1.10, 1.22), p = 1.26 × 10-8) and one spanning the 3'-UTR of an alternatively spliced transcript of SUMF1 (rs201109606, O.R. 0.65 (0.56-0.76), p = 3.24 × 10-8), had genome-wide significant associations with AD + P. Gene-based analysis identified a significant association with APOE, due to the APOE risk haplotype ε4. AD + P demonstrated negative genetic correlations with cognitive and educational attainment and positive genetic correlation with depressive symptoms. We previously observed a negative genetic correlation with schizophrenia; instead, we now found a stronger negative correlation with the related phenotype of bipolar disorder. Analysis of polygenic risk scores supported this genetic correlation and documented a positive genetic correlation with risk variation for AD, beyond the effect of ε4. We also document a small set of SNPs likely to affect risk for AD + P and AD or schizophrenia. These findings provide the first unbiased identification of the association of psychosis in AD with common genetic variation and provide insights into its genetic architecture.

Efficacy and safety of netupitant/palonosetron combination (NEPA) in preventing nausea and vomiting in non-Hodgkin's lymphoma patients undergoing to chemomobilization before autologous stem cell transplantation.

PURPOSE: Prevention of chemotherapy-induced nausea and vomiting (CINV) is particularly challenging for patients receiving highly emetogenic preparative regimens before autologous stem cell transplantation (ASCT) due to the daily and continuous emetogenic stimulus of the multiple day chemotherapy. While studies have shown effective prevention of CINV during the conditioning phase with NK1 receptor antagonist (NK1RA)-containing regimens, there have been no studies evaluating antiemetic use during chemomobilization prior to ASCT. METHODS: This multicenter, open-label, phase IIa study evaluated the efficacy of every-other-day dosing of NEPA administered during chemomobilization in patients with relapsed-refractory aggressive non-Hodgkin's lymphoma. Eighty-one patients participated. RESULTS: Response rates were 77.8% for complete response (no emesis and no rescue use), 72.8% for complete control (complete response and no more than mild nausea), 86.4% for no emesis, and 82.7% for no rescue use during the overall phase (duration of chemomobilization through 48 h after). NEPA was well tolerated with no treatment-related adverse events reported. CONCLUSION: NEPA, administered with a simplified every-other-day schedule, show to be very effective in preventing CINV in patients at high risk of CINV undergoing to chemomobilization of hematopoietic stem cells prior to ASCT.

Serum beta-secretase 1 (BACE1) activity increases in patients with mild cognitive impairment.

Beta-secretase 1 (BACE1) is considered as the key enzyme in amyloid-ß formation. Previous works suggest that high BACE1 activity may be present in brain, cerebrospinal fluid and serum of patients with late-onset Alzheimer's disease (LOAD) as well as mild cognitive impairment (MCI). Therefore, we evaluated whether serum BACE1 activity increases in MCI patients and is associated with the progression from MCI to dementia. BACE1 activity was measured in the serum of 259 MCI patients (162 amnestic-aMCI, 97 non-amnestic-naMCI) and 204 healthy Controls. After a median follow-up of 32 months (range: 10-153), 116 MCI progressed to dementia (87 aMCI and 29 naMCI). Serum BACE1 activity was higher in MCI compared with Controls (p < 0.001), and in aMCI with brain atrophy compared with naMCI without brain atrophy (p = 0.04). No difference in BACE1 activity emerged between converter and non-converter MCI, and this was true for both aMCI and naMCI. However, among aMCI with better cognitive performance (n. 163, MMSE score ≥24/30) those converting to dementia had higher BACE1 activity compared to stable ones (p = 0.05). This was not associated with an increased risk to develop dementia (hazard ratio: 1.65; 95% confidence interval: 0.67-4.01). In conclusion, serum BACE1 activity significantly increased in MCI patients (both amnestic and non-amnestic) compared with Controls. Moreover, higher serum BACE1 activity was observed only among aMCI with a better cognitive performance who progressed to dementia, suggesting that a dysregulation of this enzyme might be an early event primarily associated with neurodegeneration.

Clinical and demographic parameters predict the progression from mild cognitive impairment to dementia in elderly patients.

OBJECTIVES: To evaluate the possibility of predicting the risk of progression from mild cognitive impairment (MCI) to dementia using a combination of clinical/demographic parameters. METHODS: A total of 462 MCI elderly patients (follow-up: 33 months). Variable measured included cognitive functions, age, gender, MCI type, education, comorbidities, clinical chemistry, and functional status. RESULTS: Amnestic type (aMCI) represented 63% of the sample, non-amnestic (naMCI) 37%; 190 subjects progressed to dementia, 49% among aMCI, and 28% among naMCI. At Cox multivariate regression analysis, only MMSE (one point increase HR 0.84; 95% CI 0.79-0.90), aMCI (HR 2.35; 95% CI 1.39-3.98), and age (1 year increase HR 1.05; 95% CI 1.01-1.10) were independently associated with progression to dementia. A score was created based on these dichotomized variables (score 0-3): age (≥ or < 78 years), MMSE score (≥ or < 25/30) and aMCI type. The conversion rate progressed from 6% in subjects with score 0 (negative predictive value: 0.94), to 31% in individuals with score 1, to 53% in subjects with score 2, to 72% in individuals with score 3 (positive predictive value: 0.72). ROC curve analysis showed an area under the curve of 0.72 (95% CI 0.66-0.75, p 0.0001). CONCLUSIONS: We have described a simple score, based on previously recognized predictors such as age, MMSE, and MCI type, which may be useful for an initial stratification of the risk of progression to dementia in patients affected by MCI. The score might help the clinicians to evaluate the need for more expansive/invasive examinations and for a closer follow-up in MCI patients.

A New Presenilin 1 (Psen1) Mutation (p.Cys263Trp) as a Cause of Both Early and Late-Onset Alzheimer's Disease in a Large Italian Family.

Mutations in the PSEN1 gene are the most common cause of autosomal dominant Alzheimer's disease, and are characterized by a high phenotype variability. This study describes a five-generation family, with a prevalent late-onset of the disease and a high frequency of depression, in which a new missense mutation (c.789T > G, p.Cys263Trp) in exon 8 of the PSEN1 gene was found. Only the proband presented an early onset at the age of 45 with attention deficit, followed by spatial disorientation, psychiatric symptoms and parkinsonian signs. The other two cases had a late onset of the disease and a typical presentation with memory loss. Both were characterized by a high level of anxiety and depression. The disease course was different with signs of Lewy body dementia for the proband's mother, and pyramidal involvement and a shorter disease duration for the proband's maternal aunt. The other eight cases with late-onset dementia and three cases with a long history of depression have been reported in the family pedigree, underlying the high phenotype variability of PSEN1 mutations.

Amyloid-ß immunotherapy for alzheimer disease: Is it now a long shot?

The amyloid-ß (Aß) cascade hypothesis of Alzheimer disease (AD) holds that brain accumulation of Aß initiates the disease process. Accordingly, drug research has targeted Aß production, clearance, and deposition as therapeutic strategies. Unfortunately, candidate drugs have failed to show clinical benefit in established, early, or prodromal disease, or in those with high AD risk. Currently, monoclonal antibodies specifically directed against the most neurotoxic Aß forms are undergoing large-scale trials to confirm initially encouraging results. However, recent findings on the normal physiology of Aß suggest that accumulation may be compensatory rather than the pathological initiator. If this is true, alternative strategies will be needed to defeat this devastating disease. ANN NEUROL 2019;85:303-315.

Anti-amyloid-ß protein agents for the treatment of Alzheimer's disease: an update on emerging drugs.

INTRODUCTION: Currently available Alzheimer's disease (AD) therapeutics are only symptomatic, targeting cholinergic and glutamatergic neurotransmissions. Several putative disease-modifying drugs in late-stage clinical development target amyloid-ß (Aß) peptide and tau protein, the principal neurophatological hallmarks of the disease. AREAS COVERED: Phase III randomized clinical trials of anti-Aß drugs for AD treatment were searched in US and EU clinical trial registries and principal biomedical databases until May 2020. EXPERT OPINION: At present, compounds in Phase III clinical development for AD include four  anti-Ab monoclonal antibodies (solanezumab, gantenerumab, aducanumab, BAN2401), the combination of cromolyn sodium and ibuprofen (ALZT-OP1), and two small molecules (levetiracetam, GV-971). These drugs are mainly being tested in subjects during early AD phases or at preclinical stage of familial AD or even in asymptomatic subjects at high risk of developing AD. The actual results support the hypothesis that elevated Aß represents an early stage in the AD continuum and demonstrate the feasibility of enrolling these high-risk participants in secondary prevention trials to slow cognitive decline during the AD preclinical stages. However, a series of clinical failures may question further development of Aß-targeting drugs and the findings from current ongoing Phase III trials will hopefully give light to this critical issue.

The Challenge of Antidepressant Therapeutics in Alzheimer's Disease.

The link between depression and Alzheimer's disease (AD) is controversial, because it is not clear if depression is an independent risk factor for the disease or a prodromal symptom in the older population. Cerebral amyloid-ß (Aß) peptide deposition is associated with both cognitive symptoms and neuropsychiatric symptoms (NPS), which may be a biological mechanism of compensation. Despite the widespread use of antidepressant therapeutics (30-50% of patients with AD/dementia are on antidepressants), there is mixed evidence regarding the benefits from their use in AD depression. Monoaminergic antidepressant drugs have shown only modest or no clinical benefits. Therefore, it is important to understand the reason of this drug-resistance and the relationship between antidepressant drugs and the Aß peptide. The goal of the present review is to highlight the etiology of depression in patients affected by AD in comparison to depressive disorders without AD, and to speculate on more appropriate and alternative therapeutics.

The Role of Biomarkers in Psychiatry.

Psychiatric illnesses are cognitive and behavioral disorders of the brain. At present, psychiatric diagnosis is based on DSM-5 criteria. Even if endophenotype specificity for psychiatric disorders is discussed, it is difficult to study and identify psychiatric biomarkers to support diagnosis, prognosis, or clinical response to treatment. This chapter investigates the innovative biomarkers of psychiatric diseases for diagnosis and personalized treatment, in particular post-genomic data and proteomic analyses.

Biopsychosocial frailty and the risk of incident dementia: The Italian longitudinal study on aging.

INTRODUCTION: Frailty is a critical intermediate status of the aging process including physical, cognitive, and psychosocial domains/phenotypes. We operationalized a new biopsychosocial frailty (BF) construct, estimating its impact on the risk of incident dementia and its subtypes. METHODS: In 2171 older individuals from the population-based Italian Longitudinal Study on Aging (ILSA), we identified by latent class procedures the BF construct as the physical frail status plus at least one of the two items of the 30-item Geriatric Depression Scale impaired (items 3/10). RESULTS: Over a 3.5-year follow-up, participants with BF showed an increased risk of overall dementia (hazard ratio [HR]: 2.16, 95% confidence interval [CI]:1.07-4.37), particularly vascular dementia (VaD) (HR: 3.21, 95% CI: 1.05-9.75). Similarly, over a 7-year follow-up, an increased risk of overall dementia (HR: 1.84, 95% CI: 1.06-3.20), particularly VaD (HR: 2.53, 95% CI: 1.08-5.91), was also observed. DISCUSSION: In a large cohort of Italian older individuals without cognitive impairment at baseline, a BF model was a short- and long-term predictor of overall dementia, particularly VaD.

Late-Life Depression versus Amnestic Mild Cognitive Impairment: Alzheimer's Disease Incidence in 4 Years of Follow-Up.

BACKGROUND/AIM: The aim of the study was to evaluate the prognostic power of late-life depression (LLD) compared with amnestic mild cognitive impairment (aMCI) for the onset of Alzheimer's disease (AD) within 4 years of follow-up. METHODS: We estimated the incidence of AD in 60 patients presenting with aMCI, 115 patients suffering of LLD treated with antidepressants with good compliance, and 66 healthy control (HC) patients, followed for 4 years. RESULTS: The risk to develop AD, within 4 years, was 68.33% for aMCI and 49.57% for LLD. In AD patients 5.60% deteriorated without depression, and 72.20% deteriorated with depression after 4 years of follow-up (p < 0.0001). No HC patients deteriorated to AD or any other dementia type. CONCLUSION: In our results, aMCI was the first predictive condition that increased the risk to develop AD. Depression is a potentially preventable medical condition across the lifespan and may be a modifiable risk factor.

Innovative biomarkers in psychiatric disorders: a major clinical challenge in psychiatry.

INTRODUCTION: Currently, the diagnosis of psychiatric illnesses is based upon DSM-5 criteria. Although endophenotype-specificity for a particular disorder is discussed, the identification of objective biomarkers is ongoing for aiding diagnosis, prognosis, or clinical response to treatment. We need to improve the understanding of the biological abnormalities in psychiatric illnesses across conventional diagnostic boundaries. The present review investigates the innovative post-genomic knowledge used for psychiatric illness diagnostics and treatment response, with a particular focus on proteomics. Areas covered: This review underlines the contribution that psychiatric innovative biomarkers have reached in relation to diagnosis and theragnosis of psychiatric illnesses. Furthermore, it encompasses a reliable representation of their involvement in disease through proteomics, metabolomics/pharmacometabolomics and lipidomics techniques, including the possible role that gut microbiota and CYP2D6 polimorphisms may play in psychiatric illnesses. Expert opinion: Etiologic heterogeneity, variable expressivity, and epigenetics may impact clinical manifestations, making it difficult for a single measurement to be pathognomonic for multifaceted psychiatric disorders. Academic, industry, or government's partnerships may successfully identify and validate new biomarkers so that unfailing clinical tests can be developed. Proteomics, metabolomics, and lipidomics techniques are considered to be helpful tools beyond neuroimaging and neuropsychology for the phenotypic characterization of brain diseases.

Additive Role of a Potentially Reversible Cognitive Frailty Model and Inflammatory State on the Risk of Disability: The Italian Longitudinal Study on Aging.

OBJECTIVE: Cognitive frailty is a condition recently defined by operationalized criteria describing the simultaneous presence of physical frailty and mild cognitive impairment (MCI). Two subtypes for this clinical construct have been proposed: "potentially reversible" cognitive frailty (physical frailty plus MCI) and "reversible" cognitive frailty (physical frailty plus pre-MCI subjective cognitive decline). Here the prevalence of a potentially reversible cognitive frailty model was estimated. It was also evaluated if introducing a diagnosis of MCI in older subjects with physical frailty could have an additive role on the risk of dementia, disability, and all-cause mortality in comparison with frailty state or MCI condition alone, with analyses separately performed for inflammatory state. METHODS: In 2,373 individuals from the population-based Italian Longitudinal Study on Aging with a 3.5-year-follow-up, we operationally categorized older individuals without dementia into four groups: non-frail/non-MCI, non-frail/MCI, frail/non-MCI, and frail/MCI. RESULTS: The prevalence of potentially reversible cognitive frailty was 1%, increasing with age and more represented in women than in men, and all groups were associated with significant increased incident rate ratios of dementia, disability, and mortality. A significant difference in rates of disability has been found between the MCI and non-MCI groups (contrasts of adjusted predictions: 0.461; 95% confidence interval: 0.187-0.735) in frail individuals with high inflammatory states (fibrinogen >339 mg/dL). CONCLUSION: In older individuals without dementia and with elevated inflammation, a potentially reversible cognitive frailty model could have a significant additional predictive effect on the risk of disability than the single conditions of frailty or MCI.

Emerging biomarkers and screening for cognitive frailty.

Physical frailty and cognitive frailty are two important targets of secondary intervention in aging research to narrow the gap between life and health span. The objective of the present narrative review was to examine clinical and epidemiological studies investigating the recently proposed construct of cognitive frailty and its subtypes, with a focus on operational definitions, clinical criteria, and emerging biomarkers potentially useful for the screening of this novel entity. Both physical frailty and frailty indexes with a multidimensional nature were associated with late-life cognitive impairment/decline, incident dementia, Alzheimer's disease (AD), mild cognitive impairment, vascular dementia, non-AD dementias, and AD pathology proposing cognitive frailty as a clinical entity with cognitive impairment related to physical causes with a potential reversibility. The new clinical and research AD criteria established by the National Institute on Aging-Alzheimer's Association and the American Psychiatric Association could improve the differential diagnosis of cognitive impairment within the cognitive frailty construct. The emerging biomarkers of sarcopenia, physical frailty, and cognitive impairment will provide the basis to establish more reliable clinical and research criteria for cognitive frailty, using different operational definitions for frailty and cognitive impairment and useful clinical, biological, and imaging markers for this novel clinical construct.

Clinical and genetic analyses of familial and sporadic frontotemporal dementia patients in Southern Italy.

INTRODUCTION: We investigated the clinical differences between familial and sporadic frontotemporal dementia (FTD), screening for mutations in known FTD genes. METHODS: We diagnosed 22 affected individuals belonging to eight families and 43 sporadic cases with FTD in Apulia, Southern Italy, in 2 years. Mutations in common causative FTD genes (GRN, MAPT, VCP, and TARDBP) and C9ORF72 expansions were screened. RESULTS: Behavioral variant of FTD was the most common clinical subtype (50% and 69% in familial and sporadic cases, respectively). Social conduct impairment/disinhibition, loss of insight, and inflexibility were the most frequent clinical features observed at onset. One new mutation was identified in GRN in family A. DISCUSSION: Disease onset in sporadic FTD was more frequently characterized by a clustering of behavioral symptoms with apathy and loss of personal hygiene. Mutations in common causative FTD genes are not a major cause of familial and sporadic FTD in the Southern Italian population.

Emerging drugs to reduce abnormal ß-amyloid protein in Alzheimer's disease patients.

INTRODUCTION: Currently available drugs against Alzheimer's disease (AD) target cholinergic and glutamatergic neurotransmissions without affecting the underlying disease process. Putative disease-modifying drugs are in development and target ß-amyloid (Aß) peptide and tau protein, the principal neurophatological hallmarks of the disease. Areas covered: Phase III clinical studies of emerging anti-Aß drugs for the treatment of AD were searched in US and EU clinical trial registries and in the medical literature until May 2016. Expert opinion: Drugs in Phase III clinical development for AD include one inhibitor of the ß-secretase cleaving enzyme (BACE) (verubecestat), three anti-Aß monoclonal antibodies (solanezumab, gantenerumab, and aducanumab), an inhibitor of receptor for advanced glycation end products (RAGE) (azeliragon) and the combination of cromolyn sodium and ibuprofen (ALZT-OP1). These drugs are mainly being tested in subjects during early phases of AD or in subjects at preclinical stage of familial AD or even in asymptomatic subjects at high risk of developing AD. The hope is to intervene in the disease process when it is not too late. However, previous clinical failures with anti-Aß drugs and the lack of fully understanding of the pathophysiological role of Aß in the development of AD, put the new drugs at substantial risk of failure.

Examination of level of knowledge in Italian general practitioners attending an education session on diagnosis and management of the early stage of Alzheimer's disease: pass or fail?

BACKGROUND: We detected the general level of knowledge about the early diagnosis of Alzheimer's disease (AD) and subsequent care in general practitioners (GPs) from Southern Italy. We explored also the GP perception about their knowledge and training on diagnosis and management of AD. METHODS: On a sample of 131 GPs, we administered two questionnaires: the GP-Knowledge, evaluating GPs' expertise about AD epidemiology, differential diagnosis, and available treatments, and the GP-QUestionnaire on Awareness of Dementia (GP-QUAD), assessing the GPs' attitudes, awareness, and practice regarding early diagnosis of dementia. RESULTS: Specific screening tests or protocols to diagnose and manage dementia were not used by 53% of our GPs. The training on the recognition of early AD signs and symptoms was considered inadequate by 55% of the participants. Females were more likely to consider their training insufficient (58%) compared to males (53%). Female GPs were less likely to prescribe antipsychotic drugs to control neuropsychiatric symptoms (NPS) and suggest specialist advice in late stage of cognitive impairment. Multiple Correspondence Analysis (MCA) performed only on GP-QUAD suggested two dimensions explaining 26.1% ("GP attitude") and 20.1% ("GP knowledge") of the inertia for a total of 46.2%, CONCLUSION: In our survey on GP clinical practice, several problems in properly recognizing early AD symptoms and subsequently screening patients to be referred to secondary/tertiary care centers for diagnosis confirmation have emerged. In the future, specific training programs and educational projects for GPs should be implemented also in Italy to improve detection rates and management of dementia in primary care.

Serum paraoxonase and arylesterase activities of paraoxonase-1 (PON-1), mild cognitive impairment, and 2-year conversion to dementia: A pilot study.

Converging lines of evidence suggest that paraoxonase-1 (PON-1) may confer protection against inflammatory and oxidative challenge which, in turn, plays a key-role in the onset and progression of dementia. The aim of this study was to evaluate whether serum PON-1 paraoxonase/arylesterase activities might predict the clinical conversion of mild cognitive impairment (MCI) to late-onset Alzheimer's disease (LOAD) or vascular dementia (VAD). Serum paraoxonase and arylesterase activities were measured by spectrophotometric assays at baseline in 141 MCI patients (median age: 77 years; interquartile range 71-81) and in 78 healthy controls (median age: 76 years; interquartile range 73-79). After 2 years of follow-up, 86 MCI remained stable (MCI/MCI), 34 converted to LOAD (MCI/LOAD), whereas 21 converted to VAD (MCI/VAD). Baseline arylesterase activity was lower in all MCI groups compared with controls (all p < 0.01), whereas paraoxonase activity was lower in MCI/VAD group compared to controls (p < 0.05) and MCI/MCI patients (p = 0.009). Low paraoxonase and arylesterase activities (I quartile) were associated to higher risk of conversion to VAD (OR: 3.74, 95% CI: 1.37-10.25 and OR: 3.16, 95% CI: 1.17-8.56, respectively). Our results suggest that in MCI patients low PON-1 activity might contribute to identify individuals susceptible to develop vascular dementia.

Role of CYP2D6 Polymorphisms in the Outcome of Postoperative Pain Treatment.

OBJECTIVE: To investigate the role of CYP2D6 phenotype in the outcome of postoperative (PO) pain (POP) treatment. DESIGN: Longitudinal cohort study. Open-label trial with post hoc analysis. SETTING: General Hospital Surgery and Recovery Units. PATIENTS: Ninety unrelated Caucasians submitted to abdominal/thoracic surgery. INTERVENTIONS: Standard multimodal POP treatment including opioids (tramadol) and nonsteroidal anti-inflammatory drugs (ketoprofen) at different dosages and infusion rates according to the predicted mild, moderate, or severe POP. OUTCOME MEASURES: Pain (Numeric Rating Scale-NRS) and sedation (Ramsay Sedation Scale-RSS) up to 24 hours after surgery. By genotyping 16 CYP2D6 alleles, the four CYP2D6 phenotypes poor metabolizer (PM), intermediate metabolizers (IM), extensive metabolizers (EM) and ultrarapid metabolizers (UM) were predicted. RESULTS: As compared with the CYP2D6-EM phenotype, in the early PO time (30 min) a higher RSS mean score in IM was observed (P = 0.035). A suggestion towards higher mean score in PM (P = 0.091) and a minor mean score in UM (P = 0.091) was also detected. No difference in the outcome of pain across the CYP2D6 phenotypes was observed. CONCLUSIONS: In respect to the normal CYP2D6 phenotype, our results suggested that slowly metabolizers (IMs and PMs) might have a major sedation, whereas more rapid metabolizers (UM) a minor sedation, in the early time after surgery. A minor role of CYP2D6 phenotype in PO analgesia may be suggested.