What is the optimal serum lithium level in the long-term treatment of bipolar disorder--a review?

Magnesium-lithium thin films for neurological applications-An in vitro investigation of glial cytocompatibility and neuroinflammatory response

Lithium (Li), a widely used drug for bipolar disorder management, is associated with many side effects due to systemic exposure. The localized delivery of lithium through implants could be an approach to overcome this challenge, for which biodegradable magnesium (Mg)-based materials are a promising choice. In this study, we focus on Mg-Li thin film alloys as potential Li-releasing implants. Therefore, we investigated the in vitro short-term corrosion behavior and cytocompatibility of two alloys, Mg-1.6wt%Li and Mg-9.5wt%Li. As glial cells are the key players of foreign body responses to implants, we used human glial cell lines for cytocompatibility studies, and a murine brain slice model for a more holistic view at the neuroinflammatory response. We found that Mg-1.6wt%Li corrodes approximately six times slower than Mg-9.5wt%Li. Microscopic analysis showed that the material surface (Mg-1.6wt%Li) is suitable for cell adhesion. The cytocompatibility test with Mg-1.6wt%Li and Mg-9.5wt%Li alloy extracts revealed that both cell types proliferated well up to 10 mM Mg concentration, irrespective of the Li concentration. In the murine brain slice model, Mg-1.6wt%Li and Mg-9.5wt%Li alloy extracts did not provoke a significant upregulation of glial inflammatory/ reactivity markers (IL-1β, IL-6, FN1, TNC) after 24 h of exposure. Furthermore, the gene expression of IL-1β (up to 3-fold) and IL-6 (up to 16-fold) were significantly downregulated after 96 h, and IL-6 downregulation showed a Li concentration dependency. Together, these results indicate the acute cytocompatibility of two Mg-Li thin film alloys and provide basis for future studies to explore promising applications of the material. STATEMENT OF SIGNIFICANCE: We propose the idea of lithium delivery to the brain via biodegradable implants to reduce systemic side effects of lithium for bipolar disorder therapy and other neurological applications. This is the first in vitro study investigating Mg-xLi thin film degradation under physiological conditions and its influence on cellular responses such as proliferation, viability, morphology and inflammation. Utilizing human brain-derived cell lines, we showed that the material surface of such a thin film alloy is suitable for normal cell attachment. Using murine brain slices, which comprise a multicellular network, we demonstrated that the material extracts did not elicit a pro-inflammatory response. These results substantiate that degradable Mg-Li materials are biocompatible and support the further investigation of their potential as neurological implants.

Disrupted extracellular matrix and cell cycle genes in autism-associated Shank3 deficiency are targeted by lithium

The Shank3 gene encodes the major postsynaptic scaffolding protein SHANK3. Its mutation causes a syndromic form of autism spectrum disorder (ASD): Phelan-McDermid Syndrome (PMDS). It is characterized by global developmental delay, intellectual disorders (ID), ASD behavior, affective symptoms, as well as extra-cerebral symptoms. Although Shank3 deficiency causes a variety of molecular alterations, they do not suffice to explain all clinical aspects of this heterogenic syndrome. Since global gene expression alterations in Shank3 deficiency remain inadequately studied, we explored the transcriptome in vitro in primary hippocampal cells from Shank3∆11(-/-) mice, under control and lithium (Li) treatment conditions, and confirmed the findings in vivo. The Shank3∆11(-/-) genotype affected the overall transcriptome. Remarkably, extracellular matrix (ECM) and cell cycle transcriptional programs were disrupted. Accordingly, in the hippocampi of adolescent Shank3∆11(-/-) mice we found proteins of the collagen family and core cell cycle proteins downregulated. In vitro Li treatment of Shank3∆11(-/-) cells had a rescue-like effect on the ECM and cell cycle gene sets. Reversed ECM gene sets were part of a network, regulated by common transcription factors (TF) such as cAMP responsive element binding protein 1 (CREB1) and β-Catenin (CTNNB1), which are known downstream effectors of synaptic activity and targets of Li. These TFs were less abundant and/or hypo-phosphorylated in hippocampi of Shank3∆11(-/-) mice and could be rescued with Li in vitro and in vivo. Our investigations suggest the ECM compartment and cell cycle genes as new players in the pathophysiology of Shank3 deficiency, and imply involvement of transcriptional regulators, which can be modulated by Li. This work supports Li as potential drug in the management of PMDS symptoms, where a Phase III study is ongoing.

High lithium concentration at delivery is a potential risk factor for adverse outcomes in breastfed infants: a retrospective cohort study

BACKGROUND

Neonatal effects of late intrauterine and early postpartum exposure to lithium through mother's own milk are scarcely studied. It is unclear whether described symptoms in breastfed neonates are caused by placental lithium transfer or postnatal exposure to lithium through breastfeeding. We aimed to investigate lithium clearance and neonatal morbidity in breastfed infants with high versus low serum lithium concentrations at birth.

METHODS

This retrospective study focused on breastfed infants to women treated with lithium during and after pregnancy, born between 2006 and 2021 in Stockholm, Sweden. Information on serum lithium concentrations and adverse neonatal outcomes was obtained from medical records. Neonatal symptoms and lithium clearance were compared between a high exposure group (HEG, lithium concentrations ≥ 0.6 meq/l) and a low exposure group (LEG, < 0.6 meq/l).

RESULTS

A total of 25 infant-mother dyads were included. Median lithium serum concentration at birth was 0.90 meq/l in the HEG as compared with 0.40 meq/l in the LEG (p < 0.05). The difference was still significant at follow-up (0.20 meq/l vs 0.06 meq/l, p < 0.05), despite reduction in maternal dose. The rate of neonatal symptoms was 85.7% in HEG and 41.2% in LEG (p = 0.08) at birth and 28.6% vs 11.8% at follow-up (p = 0.55). Furthermore, 28.6% of infants in HEG were admitted to neonatal care, vs 5.9% in LEG (p = 0.19). Two infants in the HEG had therapeutic lithium levels at follow-up. All infants with symptoms at follow-up were either in the HEG or exposed to additional psychotropic medication.

CONCLUSIONS

Neonatal symptoms are common after late intrauterine lithium exposure, however transient, treatable and mostly mild. In this study, a high lithium concentration at birth was a risk factor for an increased lithium level at follow-up. Polypharmacy may constitute an additional risk factor. This study suggests that the late intrauterine exposure to lithium might add to the adverse effects in lithium-exposed, breastfed infants. Consequently we recommend breastfed infants with therapeutic lithium concentrations at birth to be followed up promptly to avoid lithium toxicity.

Clinical use of mood stabilizers beyond treatment for bipolar disorder: The REAP-MS study

OBJECTIVE

Mood stabilizers are psychotropic drugs mainly used to treat bipolar disorder in the acute phase or for maintenance therapy to prevent relapse. In clinical practice, mood stabilizers are commonly prescribed for conditions other than bipolar disorder. This study investigated the distribution of mood stabilizer prescriptions for different psychiatric diagnoses and studied differences in the drugs, dosage, and plasma concentration in 10 Asian countries including Taiwan, South Korea, Malaysia, China, Thailand, India, Pakistan, Singapore, Indonesia, and Myanmar.

METHODS

Patients prescribed mood stabilizers (lithium, carbamazepine, valproic acid, or lamotrigine) for a psychiatric condition other than bipolar disorder (codes F31.0-F31.9 in the International Classification of Diseases, 10th Edition, Clinical Modification) were recruited through convenience sampling. A website-based data entry system was used for data collection.

RESULTS

In total, 1557 psychiatric patients were enrolled. Schizophrenia, schizotypal, delusional, and other non-mood psychotic disorders (F20-F29, 55.8 %) was the most common diagnosis, followed by non-bipolar mood disorders (F30, F31- F39, 25.3 %), organic mental disorder (F00-F09, 8.8 %), mental retardation (F70-F79, 5.8 %) and anxiety, dissociative, stress-related, somatoform and other nonpsychotic mental disorders (F40-F48, 4.4 %). The most frequently targeted symptoms (>20 %) were irritability (48 %), impulsivity (32.4 %), aggression (29.2 %), anger (20.8 %), and psychosis (24.1 %). Valproic acid was the most frequently used medication.

CONCLUSIONS

Clinicians typically prescribe mood stabilizers as empirically supported treatment to manage mood symptoms in patients with diagnoses other than bipolar disorders, though there is on official indication for these disorders. The costs and benefits of this add-on symptomatic treatment warrant further investigation.

Taiwan consensus on biological treatment of bipolar disorder during the acute, maintenance, and mixed phases: The 2022 update

BACKGROUND

Bipolar disorder is a mood dysregulation characterized by recurrent symptoms and episodes of mania, hypomania, depression, and mixed mood. The complexity of treating patients with bipolar disorder prompted the Taiwanese Society of Biological Psychiatry and Neuropsychopharmacology (TSBPN) to publish the first Taiwan consensus on pharmacological treatment of bipolar disorders in 2012. This paper presents the updated consensus, with changes in diagnostic criteria (i.e., mixed features) and emerging pharmacological evidence published up to April 2022.

METHODS

Our working group systemically reviewed the clinical research evidence and international guidelines and determined the levels of evidence for each pharmacological treatment on the basis of the most recent World Federation of Societies of Biological Psychiatry grading system. Four clinical-specific issues were proposed. The current TSBPN Bipolar Taskforce then discussed research evidence and clinical experience related to each treatment option in terms of efficacy and acceptability and then appraised final recommendation grades through anonymous voting.

RESULTS

In the updated consensus, we include the pharmacological recommendations for bipolar disorder with mixed features considering its high prevalence, the severe clinical prognosis, and the absence of approved medications. Cariprazine, lurasidone, repetitive transcranial magnetic stimulation, and ketamine are incorporated as treatment options. In the maintenance phase, the application of long-acting injectable antipsychotics is emphasized, and the hazards of using antidepressants and conventional antipsychotics are proposed.

CONCLUSIONS

This updated Taiwan consensus on pharmacological treatment for bipolar disorder provides concise evidence-based and empirical recommendations for clinical psychiatric practice. It may facilitate treatment outcome improvement in patients with bipolar disorder.

Lithium levels and lifestyle in patients with bipolar disorder: a new tool for self-management

BACKGROUND

Patients should get actively involved in the management of their illness. The aim of this study was to assess the influence of lifestyle factors, including sleep, diet, and physical activity, on lithium levels in patients with bipolar disorder.

METHODS

A multicenter study was performed. In total, 157 lithium measurements were done biweekly in a sample of 65 patients (35 women) over 6 weeks. Lifestyle, based on total sleep hours and physical activity, was assessed by actigraphy. Diet was evaluated using the Mediterranean Lifestyle Index (Medlife).

RESULTS

35.4% of patients had a normal weight. The mean Medlife score was 14.5 (± 2.5) (moderate-good adherence to Mediterranean diet). BMI, daily dose of lithium and intensity of physical activity had a combined effect on lithium levels, after adjustment for other variables. Patients who practiced intense physical exercise, who took lower doses and had a higher BMI exhibited lower levels of lithium.

CONCLUSIONS

Higher physical activity and BMI contribute to lower lithium levels. Patients should be made aware of these relationships to improve their perception of control and self-management. Lifestyle-based interventions contribute to establishing a more personalized medicine.

Identifying the neuropsychiatric health effects of low-dose lithium interventions: A systematic review

BACKGROUND

Lithium is widely evidenced for its neuropsychiatric benefits. Advantages of 'sub-therapeutic' doses are increasingly being reported, which is apposite given enduring concerns around adverse effects of 'therapeutic' doses. We aimed to synthesise all available evidence from interventional studies investigating low-dose lithium (LDL) across neuropsychiatric outcomes.

METHODS

Electronic databases were systematically searched to include studies where a group of adult humans were treated with LDL (∼serum level ≤0.6 mmol/L), where data describing a neuropsychiatric outcome were reported either before and after treatment, and/or between lithium and a comparator.

RESULTS

18 articles were examined and grouped according to outcome domain (cognition, depression, mania, and related constructs e.g., suicidality). Significant benefits (versus placebo) were identified for attenuating cognitive decline, and potentially as an adjunctive therapy for people with depression/mania. Across studies, LDL was reported to be safe.

CONCLUSIONS

Despite the paucity and heterogeneity of studies, LDL's apparent pro-cognitive effects and positive safety profile open promising avenues in the fields of neurodegeneration, and augmentation in affective disorders. We urge future examinations of LDL's potential to prevent cognitive/affective syndromes.

Lithium Pharmacokinetics in the Perinatal Patient With Bipolar Disorder

The pharmacokinetics of lithium, the gold standard for the treatment of bipolar disorder, are well described in nonpregnant patients. Because lithium is commonly prescribed to women of childbearing age, more data are essential to characterize lithium pharmacokinetics during the perinatal period. Lithium is primarily eliminated by the kidney. As a result, shifts in lithium elimination clearance parallel pregnancy-related changes in glomerular filtration rate. Lithium's narrow therapeutic window increases the risk for therapeutic failure and toxicity when lithium elimination clearance is altered. To characterize the pharmacokinetics of lithium in pregnancy and postpartum, 3 women treated with lithium for bipolar disorder completed serial blood sampling protocols during each trimester of pregnancy and at least once postpartum. The trajectory of lithium elimination clearance, creatinine clearance, and serum lithium concentrations were determined. Manic, depressive, and anxiety symptoms were also assessed at each study visit. Compared to the nonpregnant state, lithium elimination clearance increased an average of 63.5% by the third trimester. Lithium elimination clearance was inversely related to changes in serum lithium concentration. Mood symptoms worsened with declines in serum lithium concentration. Lithium elimination clearance returned to baseline at 4 to 9 weeks postpartum. To maintain lithium effectiveness during pregnancy and prevent toxicity postpartum, lithium therapeutic drug monitoring and dose adjustments are warranted.

Perioperative Considerations in a Patient with Kleine–Levin Syndrome Undergoing a Neurosurgical Procedure under General Anesthesia

Kleine–Levin syndrome (KLS) is a rare central disorder of daytime hypersomnolence and is often characterized by a relapsing and remitting course, recurrent episodes of excessive sleep lasting from 12 to 20 hours a day, and symptoms including hyperphagia, hallucinations, derealization, disorientation, and hypersexuality. There are numerous perioperative considerations in dealing with KLS that include challenges during induction of anesthesia, delayed emergence, postoperative sleep disorders, and delirium. However, due to its rare occurrence, the anesthetic considerations of KLS remain poorly described. This case report outlines the anesthetic considerations and management of a young female patient with KLS who underwent transnasal excision of a trigeminal schwannoma under general anesthesia.

Population Pharmacokinetics and Dosing Regimen of Lithium in Chinese Patients With Bipolar Disorder

Background: Lithium is an effective medication approved for the treatment of bipolar disorder (BD). It has a narrow therapeutic index (TI) and requires therapeutic drug monitoring. This study aimed to conduct a population pharmacokinetics (PPK) analysis of lithium and investigate the appropriateness of the dosing regimen according to different patient characteristics.

Methods: A total of 476 lithium concentrations from 268 patients with bipolar disorder were analyzed using nonlinear mixed-effects modeling. Monte Carlo simulations were employed to investigate the influence of covariates, such as weight, creatinine clearance, and daily doses of lithium concentrations, and to determine the individualized dosing regimens for patients.

Results: Lithium PK was described by a one-compartment model with first-order absorption and elimination processes. The typical estimated apparent clearance was 0.909 L/h⁻¹ with 16.4% between-subject variability in the 62 kg patients with 116 ml/min creatinine clearance and 600 mg daily doses. To achieve a target trough concentration (0.4–0.8 mmol/L) in the maintenance phase, the regimen of 500 mg than 750 mg daily dose was recommended for patients with renal insufficiency and weighing 100 kg.

Conclusion: A PPK model for lithium was developed to determine the influence of patient characteristics on lithium pharmacokinetics. Weight, creatinine clearance, and total daily dose of lithium can affect the drug’s clearance. These results demonstrate the nonlinear renal excretion of lithium; hence, dosage adjustments are recommended for patients with renal insufficiency.

Lithium use during breastfeeding was safe in healthy full-term infants under strict monitoring

AIM

Previous studies on breastfeeding during lithium therapy have shown conflicting results. The aim of this study was to evaluate the safety when practising thorough follow-up of the infants.

METHOD

This retrospective study focused on women with lithium medication, and their breastfed infants born between 2006 and 2021 in Stockholm, Sweden. Information about infant serum lithium concentrations and clinical status was collected from medical records.

RESULTS

In total, 30 infants exposed to lithium through breastmilk, 21 girls and 9 boys, were included. The median age at follow-up was 40 days (range 8-364 days). The median lithium serum concentration was 0.10 mmol/L in the second week of life (range <0.05-0.7 mmol/L), 0.08 in week 2-4 (range <0.05-1.2), 0.06 in the second month of life (range <0.05-0.2) and 0.07 after 2 months of age (range <0.05-0.2). Unexpectedly high lithium concentrations were found in two infants in the first month of life. Apart from poor weight gain, no adverse effects were found.

CONCLUSION

Serum lithium concentrations in breastfed infants were stabilised at barely measurable levels after the first weeks of life. Before that, concentrations higher than the mothers were found. Lithium treatment during breastfeeding can be considered safe under strict follow-up.

Differences in the prophylactic effect of serum lithium levels on depression and mania in bipolar disorder: A dose-response meta-analysis

The optimal serum lithium levels for preventing the recurrence of mood episodes in bipolar disorder are controversial, especially when polarity is considered. The present study aimed to comprehensively examine the dose-response relationship between lithium concentration and risk of recurrence of mood episodes. We conducted a systematic search of major databases before January 2021 (PROSPERO: CRD42021235812). A one-stage, random-effects, restricted cubic splines model was used to estimate the dose-response relationship between lithium concentration and risk of recurrence of any or specific mood episodes (depression or mania). The effect size is shown as odds ratio (OR). Our meta-analysis included six randomised controlled trials with a total of 975 participants. The dose-response curve showed that increased serum concentrations were associated with a gradual decrease in the risk of any mood episodes (OR 0.50 at 0.60 mmol/l, OR 0.15 at 1.20 mmol/l). The risk of depression decreased slightly with a concentration of 0.60 mmol/l (OR 0.83) but dropped rapidly as the concentration increased to 1.20 mmol/l (OR 0.39). By contrast, the risk for mania initially decreased steadily (OR 0.44), but decreased only marginally (OR 0.30) as the concentration increased. To reduce the recurrence risk to 56%, prevention of depression required a higher concentration than that required for mania (1.13 mmol/l vs. 0.60 mmol/l). Our results suggest a negative dose-response relationship between serum lithium levels and risk of recurrence. In particular, the different preventive effects of serum concentration on depression and mania will be an important clinical reference.

Renal effects of long-term lithium therapy, revisited

OBJECTIVE

The aim of this study was to investigate the effect of lithium treatment on renal function and to determine influencing factors. In addition, the utility of spot urine protein/creatinine ratio in detection of lithium induced nephropathy was also investigated.

METHODS

Serum concentrations of lithium, blood urea nitrogen (BUN), creatinine, estimated glomerular filtration rate (eGFR), and urinalysis including protein/creatinine ratio were measured in 375 patients using lithium.

RESULTS

Patients taking lithium for ≥8 years had higher BUN, creatinine levels, percentage of proteinuria, percentages of stage 2 and 3 chronic kidney disease (CKD); lower urine density and eGFR compared to patients taking lithium <8 years. Urine density was lower in groups with >0.8 and 0.6-0.8 mmol/L lithium level than <0.6 mmol/L. Predictors of CKD were serum level of lithium, dose of lithium, cumulative duration of lithium use, age at onset of illness, and caffeine consumption.

CONCLUSIONS

Detrimental effects of lithium on renal functions were detected after lithium use for ≥8 years. Proteinuria measured by spot urine protein/creatinine ratio can be detected even when eGFR is >90 ml/min/1.73 m² . Spot urine protein/creatinine ratio, which is a cost-effective and practical laboratory test, can be used to monitor lithium-treated patients.

Plus ça change? Switching lithium preparations

AIMS AND METHOD

A supply disruption alert in 2020, now rescinded, notified UK prescribers of the planned discontinuation of Priadel® (lithium carbonate) tablets. This service evaluation explored lithium dose and plasma levels before and after the switching of lithium brands, in order to determine the interchangeability of different brands of lithium from a pharmacokinetic perspective.

RESULTS

Data on the treatment of 37 patients switched from Priadel® tablets were analysed. Switching to Camcolit® controlled-release tablets at the same dose did not result in meaningful differences in plasma lithium levels. Dose adjustment and known or suspected poor medication adherence were associated with greater variability in plasma lithium levels on switching brands.

CLINICAL IMPLICATIONS

For comparable pre- and post-switch doses in adherent patients, the most common brands of lithium carbonate appear to produce similar plasma lithium levels. British National Formulary guidance relating to switching lithium brands may be unnecessarily complex.

A 5-Year Study of Lithium and Valproic Acid Drug Monitoring in Patients with Bipolar Disorders in an Italian Clinical Center

Therapeutic drug monitoring (TDM) is an effective tool used to improve the pharmacological treatment in clinical practice, especially to detect subtherapeutic drug plasma concentration (Cp) in order to consider a change of dosage during treatment and reach its putative therapeutic range. In this study, we report the Cp values of lithium and valproic acid (VPA), alone and in combination, mostly in bipolar patients admitted to an Italian clinical center of the University of Pisa during the years 2016–2020, which include 12,294 samples of VPA, 7449 of lithium and 1118 of both in combination. Lithium and VPA are the most utilized drugs in treating bipolar disorders, and their TDM is strongly recommended by recent guidelines. In relation to lithium Cp monitoring, several studies have underlined that 0.5–0.8 mmol/L is the optimal range for chronic treatment, and below 0.4 mmol/L, it is unlikely to produce a clinical response. For VPA, the therapeutic range is 50–100 μg/mL and a linear correlation between Cp and clinical efficacy has been proposed, where below 50 μg/mL, the clinical efficacy of VPA has not been proven thus far. Toxic levels of both drugs were rarely found in our study, while a high percentage of patients, about one-third, had sub-therapeutic Cp during their treatments. In addition, in several cases of patients receiving multiple blood sampling, the initial subtherapeutic Cp changed only partially without reaching its therapeutic window. In relation to age, we found a higher percentage of lithium and VPA Cp values in range in the adolescents than in the adults and elderly groups. No differences were reported when analyzing the distribution of Cp values in males and females. In conclusion, this present study suggests that TDM is widely used by many specialists, but there is still a window of improvement for optimizing pharmacological treatments in clinical practice.

Dose-dependent transcriptional effects of lithium and adverse effect burden in a psychiatric cohort

Lithium is the first-line treatment for bipolar disorder (BD), but there is a large variation in response rate and adverse effects. Although the molecular effects of lithium have been studied extensively, the specific mechanisms of action remain unclear. In particular, the molecular changes underlying lithium adverse effects are little known. Multiple linear regression analyses of lithium serum concentrations and global gene expression levels in whole blood were carried out using a large case-control sample (n = 1450). Self-reported adverse effects of lithium were assessed with the "Udvalg for Kliniske Undersøgelser" (UKU) adverse effect rating scale, and regression analysis was used to identify significant associations between lithium-related genes and six of the most common adverse effects. Serum concentrations of lithium were significantly associated with the expression levels of 52 genes (FDR < 0.01), largely replicating previous results. We found 32 up-regulated genes and 20 down-regulated genes in lithium users compared to non-users. The down-regulated gene set was enriched for several processes related to the translational machinery. Two adverse effects were significantly associated (p < 0.01) with three or more lithium-associated genes: tremor (FAM13A-AS1, FAR2, ITGAX, RWDD1, and STARD10) and xerostomia (ANKRD13A, FAR2, RPS8, and RWDD1). The adverse effect association with the largest effect was between CAMK1D expression and nausea/vomiting. These results suggest putative transcriptional mechanisms that may predict lithium adverse effects, and could thus have a large potential for informing clinical practice.

Is unipolar mania a distinct entity: findings from the bipolar disorder course and outcome study from India (BiD-CoIN study)

AIM

This study aimed to evaluate the prevalence of unipolar mania (UM) in a group of patients of bipolar disorder (BD). Additionally, effort was made to evaluate the demographic, clinical and treatment related factors, which distinguish subjects of UM from BD.

METHODOLOGY

Seven hundred and seventy-three patients with BD, of at least 10 years duration, recruited from 14 General Hospital Units of tertiary care centers from India were evaluated for UM.

RESULTS

The prevalence of UM, varied from 5.4% to 20.3%, depending on the definition used. With the most stringent definition of ≥4 episodes of mania and at least 5 years of follow-up, the prevalence of UM was 5.4%. Compared to patients of BD, who have episodes other than mania too, those with UM had lower proportion of patients with lifetime history of suicide attempts, spent less time in the episodes in their lifetime and had lower severity of residual depressive and manic symptoms. Further, compared to those with episodes other than mania too, those with UM had higher number of manic episodes per year of illness, had higher proportion of patients who had more than five episodes in the lifetime and had higher proportion of those with at least one episode with psychotic symptoms in the lifetime.

CONCLUSION

The present study suggests that a small proportion of patients with BD have UM course and this runs a different clinical course compared to that seen in patients with traditionally recognized as BD.

Lithium treatment and human hippocampal neurogenesis

Lithium is a first-line treatment for bipolar disorder, where it acts as a mood-stabilizing agent. Although its precise mechanism remains unclear, neuroimaging studies have shown that lithium accumulates in the hippocampus and that chronic use amongst bipolar disorder patients is associated with larger hippocampal volumes. Here, we tested the chronic effects of low (0.75 mM) and high (2.25 mM) doses of lithium on human hippocampal progenitor cells and used immunocytochemistry to investigate the effects of lithium on cell parameters implicated in neurogenesis. Corresponding RNA-sequencing and gene-set enrichment analyses were used to evaluate whether genes affected by lithium in our model overlap with those regulating the volume of specific layers of the dentate gyrus. We observed that high-dose lithium treatment in human hippocampal progenitors increased the generation of neuroblasts (P ≤ 0.01), neurons (P ≤ 0.01), and glia (P ≤ 0.001), alongside the expression of genes, which regulate the volume of the molecular layer of the dentate gyrus. This study provides empirical support that adult hippocampal neurogenesis and gliogenesis are mechanisms that could contribute to the effects of lithium on human hippocampal volume.

Lithium concentration and recurrence risk during maintenance treatment of bipolar disorder: Multicenter cohort and meta-analysis

OBJECTIVE

To compare differences in efficacy during maintenance treatment for bipolar disorder (BD) according to lithium serum levels. A multicenter retrospective cohort study and a dose-response meta-analysis were conducted.

METHODS

The cohort study was conducted in Taiwan from 2001 to 2019 to identify patients with euthymic BD according to different serum levels (<0.4, 0.4-0.8, and 0.8-1.2 mmol/L). We adopted adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs) for time to the recurrence of mood episodes having the <0.4 mmol/L group as the reference group. Moreover, we systematically searched for related articles in major databases before January 31, 2021 (PROSPERO: CRD42021235812). We used random-effects modeling to estimate the dose-response relationships between lithium serum levels and recurrence of mood episodes, which were depicted as odds ratios (ORs) with 95% CIs.

RESULTS

A total of 1406 participants (cohort: 466; meta-analysis: 940) were included. In the cohort study, the 0.4-0.8 mmol/L group was associated with a significantly lower risk of recurrences (aHR: 0.75), while the 0.8-1.2 mmol/L group had a lower risk without statistical significance (aHR: 0.77). The dose-response meta-analysis showed that with the increase in lithium serum levels, the risk decreased (linear model OR: 0.85, for every 0.1 mmol/L increase; non-linear model OR: 1.00 at 0.0 mmol/L, 0.42 at 0.4 mmol/L, and 0.27 at 0.8 mmol/L).

CONCLUSION

Although confounding by indication cannot be excluded, the combined results suggest a significant preventative effect on the recurrence of major affective episodes among those with serum levels of 0.4-0.8 mmol/L.

Treatment adherence and tolerability of immediate- and prolonged-release lithium formulations in a sample of bipolar patients: a prospective naturalistic study

The aim of this study was to compare treatment adherence and tolerability of different lithium formulations in 70 bipolar patients receiving lithium therapy for the first time. During the 1-year follow-up, information was collected regarding patient's clinical course, therapeutic adherence, side effects of the treatment and serum levels of lithium, creatinine and thyroid-stimulating hormone. At baseline, 30 patients (43%) were on prolonged-release lithium formulations and 40 (57%) on immediate-release formulations. At the final evaluation, 37 patients (53%) were considered lost to follow-up. Both prolonged- and immediate-release patients showed significant improvement in the Functioning Assessment Short Test and in the Clinical Global Impressions for Bipolar Disorder scores during the follow-up. At the first follow-up visit, the mean plasma lithium level of prolonged-release patients was higher than immediate-release patients (0.61 vs. 0.47, respectively; P = 0.063), as well as the therapeutic adherence (85 vs. 64%, respectively; P = 0.089). Fine tremor and gastrointestinal symptoms were more frequent in immediate-release patients than in prolonged-release patients at each follow-up visit, with the sole exception of gastrointestinal symptoms at the last evaluation. Prolonged-release lithium therapy could provide potential advantages over immediate-release formulations. Future naturalistic studies and clinical trials with a longer follow-up duration are needed.

Lithium carbonate: Updated reproductive and developmental toxicity assessment using scientific literature and guideline compliant studies

The current publication describes most recent so far unpublished (key) guideline and GLP compliant reproductive and developmental toxicity studies of lithium carbonate in rats, including their interpretation and conclusions in terms of human hazard assessment when compared to existing literature. Particular attention was paid to the target organs and dose response of lithium ion related effects to differentiate between a primary (pharmacokinetic/pharmacodynamic) action and secondary effects as a result of systemic and target organ toxicity. In the key two-generation reproduction toxicity (OECD TG 416) study in rats, doses of 5, 15 and 45 mg/kg bw/d (0.95, 2.9 and 8.6 mg Li⁺/kg bw/d) were given by oral gavage, resulting in clear NOAELs of 15 mg/kg bw/d (2.9 mg Li⁺/kg bw/d) for systemic parental toxicity and 45 mg/kg bw/d (8.6 mg Li⁺/kg bw/d) for reproductive toxicity and fetal toxicity. Target organ changes were consistently observed in liver (cytoplasmic rarefaction) and kidney (dilated tubuli). In the key developmental toxicity (OECD TG 414) study in rats, doses given by oral gavage were 10, 30 and 90 mg/kg bw/d (1.9, 5.7 and 17.1 mg Li⁺/kg bw/d) was investigated resulting in NO(A)ELs of 30 mg/kg bw/d (5.7 mg Li⁺/kg bw/d) (maternal toxicity) and 90 mg/kg bw/d (17 mg Li⁺/kg bw/d) (fetal toxicity and teratogenicity). The highest dose of 90 mg/kg bw/day resulted in clear signs of toxicity and peak plasma concentrations at the toxic range (>1.0 mEq lithium/L). Toxic effects of lithium carbonate were not seen in the reproductive and developmental organs. No adverse effects on sperm (total motility, progressive motility and morphology of testicular and cauda epididymal sperm) were observed in the two-generation rat reproduction toxicity study. There was also no impact on fertility indices or on litter sizes in this study, nor were there any fetal effects in the two-generation reproduction toxicity and developmental toxicity study at doses causing already systemic toxicity in the dams. Secondary effects such as decreased weight (gain) and food consumption were reported in the developmental toxicity study. The absence of any reproductive/developmental findings at dose levels causing clear systemic toxicity in the test animals in these key mammalian studies, does not suggest an immediate concern for possible human reproductive or developmental toxicity effects from exposure to lithium during drug use.

A modified glass ionomer cement to mediate dentine repair

OBJECTIVES

Glass ionomer cements (GIC) can be used to protect dentine following caries removal. However, GIC have little biological activity on biological repair processes, which means that neo-dentine formation remains reliant on limited endogenous regenerative processes. Wnt/β-catenin signalling is known to play a central role in stimulating tertiary dentine formation following tooth damage and can be stimulated by a range of glycogen synthase kinase (GSK3) antagonists, including lithium ions.

METHODS

Here, we created lithium-containing bioactive glass (BG) by substituting lithium for sodium ions in 45S5 BG. We then replaced between 10 and 40% of the powder phase of a commercial GIC with the lithium-substituted BG to create a range of formulations of 'LithGlassGIC'. In vitro physical properties of the resulting glasses were characterised and their ability to stimulate reactionary dentine formation in mouse molars in vivo was tested.

RESULTS

Lithium release from LithGlassGIC increased with increasing lithium content in the cement. In common with unmodified commercial GIC, all formations of LithGlassGIC showed in vitro toxicity when measured using an indirect cell culture assay based on ISO10993:5, precluding direct pulp contact. However, in a murine non-exposed pulp model of tooth damage, LithGlassGIC quickly released lithium ions, which could be transiently detected in the saliva and blood. LithGlassGIC also enhanced the formation of tertiary dentine, resulting in a thickening of the dentine at the damage site that restored lost dentine volume. Dentine regeneration was likely mediated by upregulation of Wnt/β-catenin activity, as LithGlassGIC placed in TCF/Lef:H2B-GFP reporter mice showed enhanced GFP activity.

SIGNIFICANCE

We conclude that LithGlassGIC acts as a biological restorative material that promotes tertiary dentine formation and restores tooth structure.

Transcriptional analysis of sodium valproate in a serotonergic cell line reveals gene regulation through both HDAC inhibition-dependent and independent mechanisms

Sodium valproate (VPA) is a histone deacetylase (HDAC) inhibitor, widely prescribed in the treatment of bipolar disorder, and yet the precise modes of therapeutic action for this drug are not fully understood. After exposure of the rat serotonergic cell line RN46A to VPA, RNA-sequencing (RNA-Seq) analysis showed widespread changes in gene expression. Analysis by four bioinformatic pipelines revealed as many as 230 genes were significantly upregulated and 72 genes were significantly downregulated. A subset of 23 differentially expressed genes was selected for validation using the nCounter® platform, and of these we obtained robust validation for ADAM23, LSP1, MAOB, MMP13, PAK3, SERPINB2, SNAP91, WNT6, and ZCCHC12. We investigated the effect of lithium on this subset and found four genes, CDKN1C, LSP1, SERPINB2, and WNT6 co-regulated by lithium and VPA. We also explored the effects of other HDAC inhibitors and the VPA analogue valpromide on the subset of 23 selected genes. Expression of eight of these genes, CDKN1C, MAOB, MMP13, NGFR, SHANK3, VGF, WNT6 and ZCCHC12, was modified by HDAC inhibition, whereas others did not appear to respond to several HDAC inhibitors tested. These results suggest VPA may regulate genes through both HDAC-dependent and independent mechanisms. Understanding the broader gene regulatory effects of VPA in this serotonergic cell model should provide insights into how this drug works and whether other HDAC inhibitor compounds may have similar gene regulatory effects, as well as highlighting molecular processes that may underlie regulation of mood.

When and how to use lithium

BACKGROUND

Lithium is an old proven medication, but it is infrequently used in current practice. This review examines evidence for its benefits and risks and provides clinical guidance to its use.

METHOD

Narrative review.

RESULTS

Besides its benefit in bipolar illness, lithium has important underappreciated proven benefits in prevention of unipolar depression and suicide. Emerging data support neurobiological benefits for cognition and possible dementia prevention. Likely benefits also exist in low doses for mood temperaments (cyclothymia and hyperthymia). High doses (over 1.0 mmol/L) should be avoided since they increase side effects, complications associated with long-term use, and risk of toxicity. Conversely, low dosing can be legitimate, especially for suicide and dementia prevention. Nuisance side effects of lithium may affect adherence, and medically serious side-effects can occur. Managing strategies are available for side effects.

CONCLUSION

Lithium is the most effective medication in psychiatry, because it has disease-modifying, not just symptomatic, effects. It is effective not only for bipolar illness but also for prevention of suicide, episodes of unipolar depression, mood temperaments, and possibly dementia. Its many benefits need better appreciation, while lowered dosing can reduce risks.

Paper-Based Device for the Facile Colorimetric Determination of Lithium Ions in Human Whole Blood

Lithium carbonate is an effective medicine for the treatment of the bipolar disorder, but the concentration of lithium in the patient's blood must be frequently monitored because of its toxicity. To date, no colorimetric methods of lithium ion detection in whole blood without pretreatment have been reported. Here, we report a colorimetric paper-based device that allows point-of-care testing in one step. This device is composed of two paper-based elements linked to each other: a blood cell separation unit and a colorimetric detection unit. After a portion of whole blood has been placed on the end of the separation unit, plasma in the sample is automatically transported to the detection unit, which displays a diagnostic color. The key feature of this device is its simple, user-friendly operation. The limit of detection is 0.054 mM and the coefficient of variance is below 6.1%, which are comparable to those of conventional instruments using the same colorimetric reaction. Furthermore, we achieved high recovery (>90%) and reproducibility (<9.8%) with spiked human blood samples. Thus, the presented device provides an alternative method for the regular monitoring of lithium concentrations in the treatment of bipolar disorder by augmenting the coefficient of variation (maximum value, 6.1%).

ICP-MS trace element analysis in serum and whole blood

Trace elements and minerals are compounds that are essential for the support of a variety of biological functions and play an important role in the formation of and the defense against oxidative stress. Here we describe a technique, allowing sequential detection of the trace elements (K, Zn, Se, Cu, Mn, Fe, Mg) in serum and whole blood by an ICP-MS method using single work-up, which is a simple, quick and robust method for the sequential measurement and quantification of the trace elements Sodium (Na), Potassium (K), Calcium (Ca), Zinc (Zn), Selenium (Se), Copper (Cu), Iron (Fe), Manganese (Mn) and Magnesium (Mg) in whole blood as well as Copper (Cu), Selenium (Se), Zinc (Zn), Iron (Fe), Magnesium (Mg), Manganese (Mn), Chromium (Cr), Nickel (Ni), Gold (Au) and Lithium (Li) in human serum. For analysis, only 100 μl of serum or whole blood is sufficient, which make this method suitable for detecting trace element deficiency or excess in newborns and infants. All samples were processed and analyzed by ICP-MS (Agilent Technologies). The accuracy, precision, linearity and the limit of quantification (LOQ), Limit of Blank (LOB) and the limit of detection (LOD) of the method were assessed. Recovery rates were between 80–130% for most of the analyzed elements; repeatabilities (C_v %) calculated were below 15% for most of the measured elements. The validity of the proposed methodology was assessed by analyzing a certified human serum and whole blood material with known concentrations for all elements; the method described is ready for routine use in biomonitoring studies.

Exploring lithium's transcriptional mechanisms of action in bipolar disorder: a multi-step study

Lithium has been the first-line treatment for bipolar disorder (BD) for more than six decades. Although the molecular effects of lithium have been studied extensively and gene expression changes are generally believed to be involved, the specific mechanisms of action that mediate mood regulation are still not known. In this study, a multi-step approach was used to explore the transcriptional changes that may underlie lithium's therapeutic efficacy. First, we identified genes that are associated both with lithium exposure and with BD, and second, we performed differential expression analysis of these genes in brain tissue samples from BD patients (n = 42) and healthy controls (n = 42). To identify genes that are regulated by lithium exposure, we used high-sensitivity RNA-sequencing of corpus callosum (CC) tissue samples from lithium-treated (n = 8) and non-treated (n = 9) rats. We found that lithium exposure significantly affected 1108 genes (FDR < 0.05), 702 up-regulated and 406 down-regulated. These genes were mostly enriched for molecular functions related to signal transduction, including well-established lithium-related pathways such as mTOR and Wnt signaling. To identify genes with differential expression in BD, we performed expression quantitative trait loci (eQTL) analysis on BD-associated genetic variants from the most recent genome-wide association study (GWAS) using three different gene expression databases. We found 307 unique eQTL genes regulated by BD-associated variants, of which 12 were also significantly modulated by lithium treatment in rats. Two of these showed differential expression in the CC of BD cases: RPS23 was significantly down-regulated (p = 0.0036, fc = 0.80), while GRIN2A showed suggestive evidence of down-regulation in BD (p = 0.056, fc = 0.65). Crucially, GRIN2A was also significantly up-regulated by lithium in the rat brains (p = 2.2e-5, fc = 1.6), which suggests that modulation of GRIN2A expression may be a part of the therapeutic effect of the drug. These results indicate that the recent upsurge in research on this central component of the glutamatergic system, as a target of novel therapeutic agents for affective disorders, is warranted and should be intensified.

In search of optimal lithium levels and olanzapine doses in the long-term treatment of bipolar I disorder. A post-hoc analysis of the maintenance study by Tohen et al. 2005

Purpose

The aim of this study was to investigate whether lower lithium levels (LoLi) or olanzapine doses (LoOL) are risk factors for future mood episodes in patients with bipolar I disorder.

Methods

A post-hoc analysis of the olanzapine-lithium-maintenance study [31] was performed using proportional hazards Cox regression models and marginal structural models (MSMs), adjusting for non-random assignments of dose during treatment.

Results

The LoLi group (< 0.6 mmol/L) had a significantly increased risk of manic/mixed (hazard ratio [HR] = 1.96, p = 0.042), but not depressive (HR = 2.11, p = 0.272) episodes, compared to the combined medium (0.6–0.79 mmol/L) and high lithium level (≥ 0.8 mmol/L) groups. There was no significant difference in risk between the two higher lithium level groups (0.6-0.79 mmol/L; ≥ 0.8 mmol/L) for new manic/mixed (HR = 0.96, p = 0.893) or depressive (HR = 0.95, p = 0.922) episodes. The LoOL group (< 10 mg/day) showed a significantly increased risk of depressive (HR = 2.24, p = 0.025) episodes compared to the higher olanzapine (HiOL) dose group (HiOL: 10–20 mg/day), while there was no statistically significant difference in risk for manic/mixed episodes between the two groups (HR = 0.94, p = 0.895).

Conclusion

Lithium levels ≥ 0.6 mmol/L and olanzapine doses ≥ 10 mg/day may be necessary for optimal protection against manic/mixed or depressive episodes, respectively in patients with bipolar I disorder.

Differential effects of lithium isotopes in a ketamine-induced hyperactivity model of mania

Sub-anesthetic doses of ketamine produce an increase in rodent ambulation that is attenuated by co-administration of naturally-occurring lithium (LiN), the drug most commonly employed in the treatment of bipolar illness. As a consequence, ketamine-induced hyperactivity has been proposed as an animal model of manic behavior. The current study employed a modified version of this model to compare the potency of LiN to that of each of its two stable isotopes - lithium-6 (Li-6) and lithium-7 (Li-7). Since Li-7 constitutes 92.4% of the parent compound it was hypothesized to produce comparable behavioral effects to that of LiN. The current study was devised to determine whether Li-6 might be more, less, or equally effective at tempering hyperactivity relative to Li-7 or to LiN in an animal model of manic behavior. Male rats were maintained on a restricted but high-incentive diet containing a daily dose of 2.0 mEq/kg of lithium (LiN), Li-6 or Li-7 for 30 days. A control group consumed a diet infused with sodium chloride (NaCl) in place of lithium to control for the salty taste of the food. On day 30, baseline testing revealed no differences in the locomotor behavior among the four treatment groups. Animals then continued their Li/NaCl diets for an additional 11 days during which every subject received a single IP injection of either ketamine (25 mg/kg) or 0.9% physiological saline. On the final four days of this regimen, locomotor activity was assessed during 60 min sessions each beginning immediately after ketamine injection. While all three lithium groups produced comparable decreases in ketamine-induced hyperactivity on the first trial, by the fourth trial Li-6 animals exhibited significantly greater and more prolonged reductions in hyperactivity compared to either Li-7 and Li. These results suggest that Li-6 may be more effective at treating mania than its parent compound.

Lithium - Pharmacological and Toxicological Aspects: The Current State of the Art

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Lithium is the smallest monovalent cation with many different biological effects. Although lithium is present in the pharmacotherapy of psychiatric illnesses for decades, its precise mechanism of action is still not clarified. Today lithium represents first-line therapy for bipolar disorders (because it possesses both antimanic and antidepressant properties) and the adjunctive treatment for major depression (due to its antisuicidal effects). Beside, lithium showed some protective effects in neurological diseases including acute neural injury, chronic degenerative conditions, Alzheimer's disease as well as in treating leucopenia, hepatitis and some renal diseases. Recent evidence suggested that lithium also possesses some anticancer properties due to its inhibition of Glycogen Synthase Kinase 3 beta (GSK3β) which is included in the regulation of a lot of important cellular processes such as: glycogen metabolism, inflammation, immunomodulation, apoptosis, tissue injury, regeneration etc.

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Although recent evidence suggested a potential utility of lithium in different conditions, its broader use in clinical practice still trails. The reason for this is a narrow therapeutic index of lithium, numerous toxic effects in various organ systems and some clinically relevant interactions with other drugs. Additionally, it is necessary to perform more preclinical as well as clinical studies in order to a precise therapeutic range of lithium, as well as its detailed mechanism of action. The aim of this review is to summarize the current knowledge concerning the pharmacological and toxicological effects of lithium.

What is the optimal serum level for lithium in the maintenance treatment of bipolar disorder? A systematic review and recommendations from the ISBD/IGSLI Task Force on treatment with lithium

AIMS

To systematically review the existing trials on optimal serum levels for lithium for maintenance treatment of bipolar disorder and to develop clinical recommendations.

METHODS

Systematic literature search. Discussion of major characteristics, limitations, methodological quality, and results of selected trials. Delphi survey consisting of clinical questions and corresponding statements. For statements endorsed by at least 80% of the members, consensus was considered as having been achieved.

RESULTS

With strict inclusion criteria no studies could be selected, making it difficult to formulate evidence-based recommendations. After loosening the inclusion criteria 7 trials were selected addressing our aims at least to some extent. Four of these studies suggest better efficacy being associated with lithium serum levels in a range above a lower threshold around 0.45/0.60 and up to 0.80/1.00 mmol/L. These findings support the outcome of the Delphi survey.

CONCLUSIONS

For adults with bipolar disorder there was consensus that the standard lithium serum level should be 0.60-0.80 mmol/L with the option to reduce it to 0.40-0.60 mmol/L in case of good response but poor tolerance or to increase it to 0.80-1.00 mmol/L in case of insufficient response and good tolerance. For children and adolescents there was no consensus, but the majority of the members endorsed the same recommendation. For the elderly there was also no consensus, but the majority of the members endorsed a more conservative approach: usually 0.40-0.60 mmol/L, with the option to go to maximally 0.70 or 0.80 mmol/L at ages 65-79 years, and to maximally 0.70 mmol/L over age 80 years.

Toxicity and photosensitizing assessment of gelatin methacryloyl-based hydrogels photoinitiated with lithium phenyl-2,4,6-trimethylbenzoylphosphinate in human primary renal proximal tubule epithelial cells

Gelatin methacryloyl (GelMA) and lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP) photoinitiator are commonly used in combination to produce a photosensitive polymer but there are concerns that must be addressed: the presence of unreacted monomer is well known to be cytotoxic, and lithium salts are known to cause acute kidney injury. In this study, acellular 10% GelMA hydrogels cross-linked with different LAP concentrations and cross-linking illumination times were evaluated for their cytotoxicity, photosensitizing potential, and elastic moduli. Alamar Blue and CyQuant Direct Cell viability assays were performed on human primary renal proximal tubule epithelial cells (hRPTECs) exposed to extracts of each formulation. UV exposure during cross-linking was not found to affect extract cytotoxicity in either assay. LAP concentration did not affect extract cytotoxicity as determined by the Alamar Blue assay but reduced hRPTEC viability in the CyQuant Direct cell assay. Photocatalytic activity of formulation extracts toward NADH oxidation was used as a screening method for photosensitizing potential; longer UV exposure durations yielded extracts with less photocatalytic activity. Finally, elastic moduli determined using nanoindentation was found to plateau to approximately 20-25 kPa after exposure to 342 mJ/cm² at 2.87 mW of UV-A exposure regardless of LAP concentration. LAP at concentrations commonly used in bioprinting (<0.5% w/w) was not found to be cytotoxic although the differences in cytotoxicity evaluation determined from the two viability assays imply cell membrane damage and should be investigated further. Complete cross-linking of all formulations decreased photocatalytic activity while maintaining predictable final elastic moduli.

Compliance with the safety guidelines for long-term lithium treatment in Sweden

BACKGROUND

Lithium has been used for more than 50 years and guidelines for treatment monitoring have been documented in Sweden since the beginning of the 1980s.

AIMS

The aim of this study was to describe compliance over time with the Swedish guidelines for long-term lithium treatment.

METHODS

The study material was obtained from Sahlgrenska University Hospital's laboratory database. We analysed data (serum lithium and serum creatinine) of adult patients treated with lithium between 1981 and 2010, and determined compliance with guidelines and serum lithium levels over time.

RESULTS

Our study material included 2841 patients and 25,300 treatment-years. The compliance with guidelines' recommendations regarding lithium and creatinine monitoring increased from 36% in 1981 to 68% in 2010. Women were on average 2% more compliant than men ( p < 0.01). Most lithium samples (87-94%) were within recommended intervals throughout the study period. The average lithium level decreased from 0.70 mmol/L in 1981 to 0.58 mmol/L in 2001, and remained stable thereafter.

CONCLUSIONS

Compliance with lithium monitoring guidelines improved slowly but steadily over time. It took three decades to reach a compliance rate of just below 70%. Gender differences were small, but with a significantly better compliance rate for women. Serum lithium was kept within the recommended target interval to a large extent, throughout the study period.

Lithium, Stress, and Resilience in Bipolar Disorder: Deciphering this key homeostatic synaptic plasticity regulator

BACKGROUND

Lithium is the lightest metal and the only mood stabilizer that has been used for over half a century for the treatment of bipolar disorder (BD). As a small ion, lithium is omnipresent, and consequently, its molecular mechanisms and targets are widespread. Currently, lithium is a crucial pharmacotherapy for the treatment of acute mood episodes, prophylactic therapy, and suicide prevention in BD. Besides, lithium blood level is the most widely used biomarker in clinical psychiatry. The concept of stress in BD characterizes short- and long-term deleterious effects at multiple levels (from genes to behaviors) and the ability to establish homeostatic regulatory mechanisms to either prevent or reverse these effects. Within this concept, lithium has consistently shown anti-stress effects, by normalizing components across several levels associated with BD-induced impairments in cellular resilience and plasticity.

METHODS

A literature search for biomarkers associated with lithium effects at multiple targets, with a particular focus on those related to clinical outcomes was performed. An extensive search of the published literature using PubMed, Medline and Google Scholar was performed. Example search terms included lithium, plasticity, stress, efficacy, and neuroimaging. Articles determined by the author to focus on lithium's impact on neural plasticity markers (central and periphery) and clinical outcomes were examined in greater depth. Relevant papers were evaluated, selected and included in this review.

RESULTS

Lithium induces neurotrophic and neuroprotective effects in a wide range of preclinical and translational models. Lithium's neurotrophic effects are related to the enhancement of cellular proliferation, differentiation, growth, and regeneration, whereas its neuroprotective effects limit the progression of neuronal atrophy or cell death following the onset of BD. Lithium's neurotrophic and neuroprotective effects seem most pronounced in the presence of pathology, which again supports its pivotal role as an active homeostatic regulator.

LIMITATIONS

Few studies associated with clinical outcomes. Due to space limitations, the author was unable to detail all findings, in special those originated from preclinical studies.

CONCLUSIONS

These results support a potential role for biomarkers involved in neuroprotection and activation of plasticity pathways in lithium's clinical response. Evidence supporting this model comes from results evaluating macroscopic and microscopic brain structure as well neurochemical findings in vivo from cellular to sub-synaptic (molecules and intracellular signaling) compartments using central and peripheral biomarkers. Challenges to precisely decipher lithium's biological mechanisms involved in its therapeutic profile include the complex nature of the illness and clinical subtypes, family history and comorbid conditions. In the context of personalized medicine, it is necessary to validate predictive biomarkers of response to lithium by designing longitudinal clinical studies during mood episodes and associated clinical dimensions in BD.

Monitoring of patients treated with lithium for bipolar disorder: an international survey

Background

Adequate monitoring of patients using lithium is needed for optimal dosing and for early identification of patients with (potential) ADEs. The objective was to internationally assess how health care professionals monitor patients treated with lithium for bipolar disorder.

Methods

Using networks of various professional organizations, an anonymous online survey was conducted among health care professionals prescribing lithium. Target lithium serum levels and frequency of monitoring was assessed together with monitoring of physical and laboratory parameters. Reasons to and not to monitor and use of guidelines and institutional protocols, and local monitoring systems were investigated.

Results

The survey was completed by 117 health care professionals incorporating responses from twenty-four countries. All prescribers reported to monitor lithium serum levels on a regular basis, with varying target ranges. Almost all (> 97%) monitored thyroid and renal function before start and during maintenance treatment. Reported monitoring of other laboratory and physical parameters was variable. The majority of respondents (74%) used guidelines or institutional protocols for monitoring. In general, the prescriber was responsible for monitoring, had to request every monitoring parameter separately and only a minority of patients was automatically invited.

Conclusions

Lithium serum levels, renal and thyroid function were monitored by (almost) all physicians. However, there was considerable variation in other monitoring parameters. Our results help to understand why prescribers of lithium monitor patients and what their main reasons are not to monitor patients using lithium.

Electronic supplementary material

The online version of this article (10.1186/s40345-018-0120-1) contains supplementary material, which is available to authorized users.

Lithium in Bipolar Disorder: Optimizing Therapy Using Prolonged-Release Formulations

Lithium has been a gold standard in the treatment of bipolar disorder (BD) for several decades. Despite a general reduction in the use of lithium over the past several years, it is effective in the management of both manic and depressive episodes in BD and continues to be recommended as a first-line mood stabilizer. This review provides an overview of the pharmacology of lithium and highlights its clinical profile in the management of BD, focusing on the potential advantages of prolonged-release (PR) versus immediate-release (IR) formulations of lithium. A literature search using PubMed was performed to identify articles describing IR and PR lithium in BD using specific search terms like ‘lithium’, ‘prolonged-release’, ‘sustained-release’, ‘extended-release’, ‘bipolar disorder’, ‘adherence’ and ‘compliance’. Relevant pharmacodynamic and pharmacokinetic data were also included. Several clinical trials suggested that lithium is effective in the treatment of acute mania and prophylaxis of BD and reduces the risk of suicide in patients with BD; it may also be used in combination with other drugs in the treatment of bipolar depression. Treatment with lithium must be monitored to avoid lithium-associated toxicity. The prolonged PR formulation of lithium has several advantages including consistent serum lithium concentrations, fewer adverse events and improved adherence to therapy. Although direct comparative studies between PR and IR formulations of lithium are primarily limited to pharmacokinetic studies, PR formulation of lithium provides potential advantages over IR formulation and can be effectively used in the management of BD with lesser adverse events.

BACE1 inhibition by microdose lithium formulation NP03 rescues memory loss and early stage amyloid neuropathology

Lithium is first-line therapy for bipolar affective disorder and has recently been shown to have protective effects in populations at risk for Alzheimer's disease (AD). However, the mechanism underlying this protection is poorly understood and consequently limits its possible therapeutic application in AD. Moreover, conventional lithium formulations have a narrow therapeutic window and are associated with a severe side effect profile. Here we evaluated a novel microdose formulation of lithium, coded NP03, in a well-characterized rat model of progressive AD-like amyloid pathology. This formulation allows microdose lithium delivery to the brain in the absence of negative side effects. We found that NP03 rescued key initiating components of AD pathology, including inactivating GSK-3β, reducing BACE1 expression and activity, and reducing amyloid levels. Notably, NP03 rescued memory loss, impaired CRTC1 promoter binding of synaptic plasticity genes and hippocampal neurogenesis. These results raise the possibility that NP03 be of therapeutic value in the early or preclinical stages of AD.

Lithium dosing strategies during pregnancy and the postpartum period

BackgroundLithium is challenging to dose during pregnancy.AimsTo provide guidance for dosing lithium during pregnancy.MethodRetrospective observational cohort study. Data on lithium blood level measurements (n = 1101), the daily lithium dose, dosing alterations/frequency and creatinine blood levels were obtained from 113 pregnancies of women receiving lithium treatment during pregnancy and the postpartum period.ResultsLithium blood levels decreased in the first trimester (-24%, 95% CI -15 to -35), reached a nadir in the second trimester (-36%, 95% CI -27 to -47), increased in the third trimester (-21%, 95% CI -13 to -30) and were still slightly increased postpartum (+9%, 95% CI +2 to +15). Delivery itself was not associated with an acute change in lithium and creatinine blood levels.ConclusionsWe recommend close monitoring of lithium blood levels until 34 weeks of pregnancy, then weekly until delivery and twice weekly for the first 2 weeks postpartum. We suggest creatinine blood levels are measured to monitor renal clearance.

Use of Lithium in Severe Acute Manic Episodes: Retrospective Prescription Practice From a Tertiary Inpatient Unit

OBJECTIVE

A retrospective chart review was performed to investigate the common preferences of clinicians for the pharmacological treatment of acute manic episodes, with particular regard to lithium use, and to assess the adherence of clinical practice to established guidelines.

METHODS

Cases of manic episodes in patients admitted to Bakirköy Mazhar Osman Mental Health and Neurological Diseases Education and Research Hospital were retrospectively reviewed. Length of stay, medication data, serum levels, and adverse effects were evaluated for patients who received lithium therapy (N=98).

RESULTS

On the first day of lithium treatment, 81 patients received 900 to 1200 mg of lithium. In total, 44 patients were discharged with the same dose as that given on the first day of treatment. With the exception of 1 patient, the dose was increased by 300 to 600 mg in the remaining patients within the first 10 days on the basis of serum drug concentrations. The mean serum concentrations of lithium in the first week were 0.67±0.17 mEq/L in patients with no dose increase, and 0.51±0.15 mEq/L in patients who did receive a dose increase. In total, 94 patients received at least 1 antipsychotic medication in addition to lithium.

CONCLUSIONS

Clinicians attempted to maintain serum lithium levels above 0.60 mEq/L at the time of acute treatment initiation, consistent with established guidelines. Clinical practice in large inpatient settings may force clinicians to use lithium in combination with antipsychotics for the treatment of acute mania; the delayed action of lithium and the need for rapid stabilization may drive these practices.

Lithiumeter: Version 2.0

BACKGROUND

The Lithiumeter was developed as a visual and practical guide for determining lithium levels in the management of bipolar disorder (BD). It appears to have been well received, as evidenced by its increasing popularity amongst doctors as a deskside clinical aide, and adoption and reproduction of the schematic in clinical guidelines and texts. However, since its publication 5 years ago, key basic neuroscience and clinical research developments pertaining to lithium have significantly advanced our understanding, necessitating further refinement of guidance concerning the practicalities of lithium therapy.

METHODS

Literature concerning the indications for, and therapeutic levels of, lithium and the associated acute and chronic risks of therapy was scrutinized as part of updating clinical practice guidelines. We have reviewed these updates and identified significant areas of change with respect to the previous Lithiumeter (version 1.0).

RESULTS

Since 2011, updated clinical practice guidelines have narrowed the indicated plasma lithium concentration for maintenance therapy, suggesting that additional guidance is necessary for optimizing treatment. Relevant updated clinical guidance was integrated to constitute the Lithiumeter 2.0, which provides a more comprehensive overview of the practical aspects of lithium therapy while maintaining a focus on optimization of lithium levels, such as differential titration of lithium depending on the current mood state.

CONCLUSIONS

The Lithiumeter 2.0 is an update that clinicians will find useful for their practice. By addressing some of the issues faced in clinical practice, translational clinical research will continue to inform the Lithiumeter in future updates.

Lithium-Responsive Seizure-Like Hyperexcitability Is Caused by a Mutation in the Drosophila Voltage-Gated Sodium Channel Gene paralytic

Shudderer (Shu) is an X-linked dominant mutation in Drosophila melanogaster identified more than 40 years ago. A previous study showed that Shu caused spontaneous tremors and defects in reactive climbing behavior, and that these phenotypes were significantly suppressed when mutants were fed food containing lithium, a mood stabilizer used in the treatment of bipolar disorder (Williamson, 1982). This unique observation suggested that the Shu mutation affects genes involved in lithium-responsive neurobiological processes. In the present study, we identified Shu as a novel mutant allele of the voltage-gated sodium (Na_v) channel gene paralytic (para). Given that hypomorphic para alleles and RNA interference-mediated para knockdown reduced the severity of Shu phenotypes, Shu was classified as a para hypermorphic allele. We also demonstrated that lithium could improve the behavioral abnormalities displayed by other Na_v mutants, including a fly model of the human generalized epilepsy with febrile seizures plus. Our electrophysiological analysis of Shu showed that lithium treatment did not acutely suppress Na_v channel activity, indicating that the rescue effect of lithium resulted from chronic physiological adjustments to this drug. Microarray analysis revealed that lithium significantly alters the expression of various genes in Shu, including those involved in innate immune responses, amino acid metabolism, and oxidation-reduction processes, raising the interesting possibility that lithium-induced modulation of these biological pathways may contribute to such adjustments. Overall, our findings demonstrate that Na_v channel mutants in Drosophila are valuable genetic tools for elucidating the effects of lithium on the nervous system in the context of neurophysiology and behavior.

A Review of Pharmacological Treatments for Depression in Alzheimer's Disease

Depression in Alzheimer's disease (dAD) is one of the most common behavioral and psychological symptoms of dementia, with devastating consequences not only for the affected individuals, but for caregivers as well. So far, pharmacological treatment of dAD has been based on the "monoamine hypothesis". However, the reported moderate effects of approved antidepressants, as well as an increasing body of research evidence, suggest a more complex pathophysiologic mechanism. In the present paper, a systematic review of different treatments for dAD is presented that can inform the study of alternative neuropathological and neurobiological aspects of the disease aimed at the development of more effective treatment targets.

Distinct Structural Pathways Coordinate the Activation of AMPA Receptor-Auxiliary Subunit Complexes

Neurotransmitter-gated ion channels adopt different gating modes to fine-tune signaling at central synapses. At glutamatergic synapses, high and low activity of AMPA receptors (AMPARs) is observed when pore-forming subunits coassemble with or without auxiliary subunits, respectively. Whether a common structural pathway accounts for these different gating modes is unclear. Here, we identify two structural motifs that determine the time course of AMPAR channel activation. A network of electrostatic interactions at the apex of the AMPAR ligand-binding domain (LBD) is essential for gating by pore-forming subunits, whereas a conserved motif on the lower, D2 lobe of the LBD prolongs channel activity when auxiliary subunits are present. Accordingly, channel activity is almost entirely abolished by elimination of the electrostatic network but restored via auxiliary protein interactions at the D2 lobe. In summary, we propose that activation of native AMPAR complexes is coordinated by distinct structural pathways, favored by the association/dissociation of auxiliary subunits.

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Two distinct structural motifs control the time course of AMPA receptor gating

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Intraprotein electrostatic interactions govern gating by pore-forming subunits

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Auxiliary subunits act at a distinct site to prolong channel activity

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Intra- and interprotein interactions coordinate signaling by AMPA receptor complexes

An exploratory study of responses to low-dose lithium in African Americans and Hispanics

OBJECTIVES

Few prospective studies examine the impact of ethnicity or race on outcomes with lithium for bipolar disorder. This exploratory study examines differences in lithium response and treatment outcomes in Hispanics, African Americans, and non-Hispanic whites with bipolar disorder in the Lithium Treatment Moderate Dose Use Study (LiTMUS).

METHODS

LiTMUS was a six-site randomized controlled trial of low-dose lithium added to optimized treatment (OPT; personalized, evidence-based pharmacotherapy) vs. OPT alone in outpatients with bipolar disorder. Of 283 participants, 47 African Americans, 39 Hispanics, and 175 non-Hispanic whites were examined. We predicted minority groups would have more negative medication attitudes and higher attrition rates, but better clinical outcomes.

RESULTS

African Americans in the lithium group improved more on depression and life functioning compared to whites over the 6 month study. African Americans in the OPT only group had marginal improvement on depression symptoms. For Hispanics, satisfaction with life did not significantly improve in the OPT only group, in contrast to whites and African Americans who improved over time on all measures. Attitudes toward medications did not differ across ethnic/racial groups.

CONCLUSIONS

African Americans show some greater improvements with lithium than non-Hispanic whites, and Hispanics showed more consistent improvements in the lithium group. The impact of low-dose lithium should be studied in a larger sample as there may be particular benefit for African Americans and Hispanics. Given that the control group (regardless of ethnicity/race) had significant improvements, optimized treatment may be beneficial for any ethnic group.

World Federation of Societies of Biological Psychiatry (WFSBP) guidelines for biological treatment of unipolar depressive disorders. part 2: maintenance treatment of major depressive disorder-update 2015

These guidelines for the treatment of unipolar depressive disorders systematically review available evidence pertaining to the biological treatment of patients with major depression and produce a series of practice recommendations that are clinically and scientifically meaningful based on the available evidence. These guidelines are intended for use by all physicians assessing and treating patients with these conditions. The relevant data have been extracted primarily from various treatment guidelines and panels for depressive disorders, as well as from meta-analyses/reviews on the efficacy of antidepressant medications and other biological treatment interventions identified by a search of the MEDLINE database and Cochrane Library. The identified literature was evaluated with respect to the strength of evidence for its efficacy and was then categorized into five levels of evidence (CE A-F) and five levels of recommendation grades (RG 1-5). This second part of the WFSBP guidelines on depressive disorders covers the management of the maintenance phase treatment, and is primarily concerned with the biological treatment (including pharmacological and hormonal medications, electroconvulsive therapy and other brain stimulation treatments) of adults and also, albeit to a lesser extent, children, adolescents and older adults.