Lithium toxicity: an iatrogenic problem in susceptible individuals

Human brain 7Li-MRI following low-dose lithium dietary supplementation in healthy participants

BACKGROUND

Lithium is an effective mood stabiliser, but its mechanism of action is incompletely defined. Even at very low doses, lithium may have neuroprotective effects, but it is not clear if these relate to brain lithium concentration in vivo. We have developed magnetic resonance imaging (7Li-MRI) methods to detect lithium in the brain following supplementation at a very low dose.

METHODS

Lithium orotate supplements were taken by nine healthy adult male subjects (5 mg daily) for up to 28 days, providing 2-7 % of the lithium content of a typical therapeutic lithium carbonate dose. One-dimensional 7Li-images were acquired on a 3.0 T MRI scanner. All subjects were scanned on day 14 or 28; seven were scanned on both, one at baseline and one after 7-days washout.

RESULTS

7Li-MR signal amplitude was broadly stable between days 14 and 28. Two subjects had notably higher 7Li-signal intensities (approximately 2-4×) compared to other study participants.

LIMITATIONS

Lithium adherence was self-reported by all participants without formal validation. The coarse spatial resolution necessary for detection of low concentrations of 7Li exhibits imperfect spatial separation of signal from adjacent pixels.

CONCLUSIONS

7Li-MRI performed using a clinical 3T scanner demonstrated detection of lithium in the brain at very low concentration, in the range of approximately 10-60 mM. The methods are suited to studies assessing low dose lithium administration in psychiatric and neurodegenerative disorders, and permit the comparison of different lithium salt preparations at a time of emerging interest in the field.

Chronic Lithium Intoxication: A Challenging Diagnosis

Lithium has been used in clinical practice since the 1970s. This medication is commonly used to treat and prevent bipolar disorder, but it has a narrow therapeutic index, making toxicity a frequent occurrence. Chronic lithium intoxication can arise due to progressive accumulation, particularly in contexts of dehydration. The effects of chronic lithium intoxication on the nervous, renal, and cardiac systems, as well as on the thyroid and parathyroid glands, are well documented in the literature. The authors present the case of a 66-year-old woman with schizoaffective psychosis and chronic kidney disease, admitted due to altered mental status and dysarthria. Notwithstanding an earlier clinical recommendation to cease lithium administration more than a year ago, the patient continued its usage, culminating in neurological, cardiac, renal, and endocrine manifestations. Although the diagnosis was delayed, her clinical progression was favorable, obviating the need for renal replacement therapy. This case highlights the importance of a detailed medical history and the diagnostic challenges in clinical practice. The use of this drug without proper monitoring can lead to multisystem dysfunction.

Causes, clinical characteristics, and outcomes of high lithium levels and intoxications: Retrospective analysis of patient records

BACKGROUND

The mood stabilizer lithium has a narrow therapeutic index with a relevant risk of intoxication. We used real-world hospital data to identify causes, treatment courses, and outcomes of high lithium levels and intoxications.

METHODS

Retrospective chart review of patients with a lithium concentration of ⩾1.1 mmol/L, who were treated at Charité University Medical Center Berlin.

RESULTS

We identified 136 patients (58% women; mean age: 54.7 years) with high lithium levels or intoxication. 66.9% were chronic (stable lithium dose but changes in other variables such as co-medication). 40.4% took at least one risk medication with a relative contraindication for concurrent lithium treatment. 11.1% of the cases with a high therapeutic level showed moderate to severe intoxications. Feverish infections were significantly associated with severe intoxications. Overall, 97.1% (132/136) of patients fully recovered, two had residual but mild symptoms and two died during hospitalization (unlikely related to the intoxication). In 37.5% of patients, no psychiatrist was involved in the management of high lithium levels or intoxication. In these patients, lithium treatment was adjusted or discontinued in 37.3% of the cases compared to 64.7% when a psychiatrist was involved (χ²(1) = 9.683, p = 0.002).

CONCLUSIONS

Patients and medical doctors should be aware of the increased risk of lithium intoxication already within the high therapeutic range and should consider alternative medications without relative contraindications for concurrent lithium use. Involving psychiatrists during or after an intoxication event is associated with more frequent adjustment of the maintenance lithium dose and should be considered in most cases.

Management of lithium intoxication

Lithium is a gold standard maintenance treatment in bipolar affective disorder. It has a narrow therapeutic range, and at higher serum lithium levels there is a risk of adverse effects and toxicity. There are three patterns of lithium intoxication: acute, acute-on-chronic and chronic. We describe risk factors for lithium intoxication, mechanisms of toxicity and clinical symptoms seen in lithium intoxication. We describe both the acute and chronic effects of lithium toxicity. Lithium intoxication may be life-threatening and associated with longer-term sequelae. The management of lithium intoxication involves determining the type of intoxication. We discuss treatment strategies aimed at reducing absorption and increasing elimination of lithium. We discuss clinical indications for extracorporeal methods such as dialysis, which are used to limit the time and degree of exposure of the central nervous system to toxic lithium concentrations. Haemodialysis is the most rapid method of eliminating lithium from the body, but careful monitoring is required. Preventive strategies to mitigate the risk for lithium intoxication are discussed.

Evaluation of the utilization of extracorporeal toxin removal in lithium poisoning patients in Hong Kong

Background:

Extracorporeal toxin removal is used for enhanced elimination in severe lithium poisoning. The Extracorporeal TReatments In Poisoning workgroup provides recommendations on the use of extracorporeal toxin removal in poisoning.

Objectives:

Our aim was to identify the pattern for using extracorporeal toxin removal in managing lithium poisoning in Hong Kong and compare the outcomes in extracorporeal toxin removal-treated patients and non-extracorporeal toxin removal-treated patients if indicated for treatment as defined by The Extracorporeal TReatments In Poisoning criteria.

Methods:

Lithium poisoning presented between year 2009 and 2019 in Hong Kong Poison Information Centre (HKPIC) database was categorized into extracorporeal toxin removal-treated group and non-extracorporeal toxin removal-treated group. Comparative analyses were performed.

Results:

Among 112 lithium-poisoned patients, 21% were treated with extracorporeal toxin removal. Larger proportion of patients had fulfilled at least one Extracorporeal TReatments In Poisoning criteria for extracorporeal toxin removal in the extracorporeal toxin removal-treated group (87% vs 18%, p < 0.005). The extracorporeal toxin removal-treat group patients were more commonly presented with impaired consciousness, seizure and dysrhythmia ( p < 0.05). They also got higher admission (3.62 mmol/L vs 2.18 mmol/L, p < 0.05) and peak (4.15 mmol/L vs 2.28 mmol/L, p < 0.05) serum lithium concentrations, as well as a significantly higher serum creatinine concentration upon presentation (263.74 µmol/L vs 98.66 µmol/L, p < 0.05). Extracorporeal toxin removal-treat group patients more frequently had a severe poisoning outcome (91.3% vs 9%, p < 0.05) and developed complications (69.6% vs 13.5%, p < 0.05). Logistic regression identified seizure, peak serum lithium concentration, and serum creatinine concentration upon presentation as risk factors for severe poisoning outcome. In subgroup analysis on patients with at least one indication for extracorporeal toxin removal as defined by Extracorporeal TReatments In Poisoning criteria, the proportion of severe poisoning remained higher in the extracorporeal toxin removal-treated group (90% vs 43.7%, p < 0.05). Complication rate was not significantly different between the two groups.

Conclusion:

Clinically severe lithium poisoning patients were treated with extracorporeal toxin removal in Hong Kong. Extracorporeal TReatments In Poisoning criteria can serve as a reference in considering extracorporeal toxin removal treatment for lithium poisoning patients. Nevertheless, Extracorporeal TReatments In Poisoning criteria recommend more extracorporeal toxin removal treatment than it was actually done. Lithium poisoning patients with positive Extracorporeal TReatments In Poisoning criteria have been managed without extracorporeal toxin removal. No statistically significant adverse outcome was observed in these cases.

An Atypical Presentation of Serotonin Syndrome

The purpose of this paper is to highlight an uncommon presentation of serotonin syndrome and discuss important points such as causes, the manifestation of symptoms, and available treatments. The report highlights the importance of recognizing typical signs and symptoms in order to uncover an atypical presentation of serotonin syndrome. Serotonin toxicity can become life-threatening if not identified early in its course and the offending agents discontinued. This can be achieved by educated physicians and careful prescribing of these agents.

[Neurological complications attributable to lithium: An update]

Lithium intoxication may induce neurological complications, initially characterised by a conscience alteration and an encephalopathy clinical picture with a risk of death or sever long-term consequences. With an occurrence sometimes atypical and possibly without initial hyperlitemia, the diagnosis delay of these complications might be important. Moreover, no specific guidelines focused on these complications are available. The aim of this article is to propose an update on diagnosis and treatment of neurological complications attributable to lithium, as encephalopathy.

A Case Report on an Atypical Presentation of the Syndrome of Irreversible Lithium-Effectuated Neurotoxicity (SILENT) in a War Veteran with Bipolar Disorder and PTSD

Background

Lithium is still the first-line agent for bipolar disorder. Despite common knowledge on monitoring lithium levels to prevent toxicity, it still occurs at varying degrees. Here we present a rare sequela of lithium toxicity, the Syndrome of Irreversible Lithium-Effectuated Neurotoxicity (SILENT). Case Presentation. A 56-year-old male war veteran who is fully functional despite being on chronic lithium therapy for Posttraumatic Stress Disorder (PTSD) and bipolar disorder presented at the emergency room with altered mental status and seizures associated with elevated lithium levels and renal insufficiency. Antiepileptic drugs were given for seizure control, and intermittent hemodialysis was done to clear the lithium. Despite clearance of the offending agent, the patient remained to have a generalized slowing on repeated EEG with only eye opening and nonpurposeful limb movements regained even after more than 2 months of lithium cessation.

Conclusion

SILENT has been coined after reports of persistent neurologic deficits were seen in patients who experienced lithium toxicity more than 2 months after cessation of lithium. Chronic lithium therapy predisposes to gradual accumulation of lithium in the brain. Demyelination is the typically reported feature of SILENT. It can also leave the patient in a persistent encephalopathic state. Chronic lithium toxicity from failure of monitoring puts patients on lithium therapy at risk.

Neurotoxicity in chronic lithium poisoning

BACKGROUND

Lithium-induced neurotoxicity typically occurs with chronic accumulation rather than following acute overdose. There is little emphasis in the literature on the protracted nature of lithium neurotoxicity long after the lithium concentration returns to the therapeutic range.

AIMS

To characterise lithium neurotoxicity, with a view of increasing awareness of this important phenomenon.

METHODS

This is a retrospective observational study of patients presenting with lithium-induced neurotoxicity over a 5-year period to a clinical toxicology unit. Patients were identified through the unit's database, and clinical notes were analysed.

RESULTS

There were 22 patients, with a median age of 65 (range: 36-89) years. Six patients (27%) had previous lithium toxicity, and nine (41%) were regularly prescribed medications that impair lithium excretion. The median lithium concentration on presentation was 2.2 mmol/L, taking a median of 3 days to return to the therapeutic range. Reversible acute kidney injury was observed in 21 patients (95%) on presentation. The median length of stay was 13 (range: 3-95) days due mostly to delayed neurological recovery. Confusion was the predominant symptom, present in 21 (95%) patients, followed by tremors (18(82%)) and ataxia (16(73%)). Multiple investigations were performed to exclude delirium differentials, including 11 computed tomography (CT) and five magnetic resonance imaging (MRI) brain scans, all unremarkable.

CONCLUSIONS

Lithium neurotoxicity has a prolonged course. Its severity correlates poorly with lithium concentrations, which normalise quickly. Most poisonings occur in elderly patients with acute kidney injury. Prolonged delirium often prompts multiple unnecessary investigations. Rationalisation of lithium therapy is important in elderly patients.

Effect of age on the severity of chronic lithium poisoning

Objectives: Severe lithium toxicity is commonly observed in older people. We aimed to determine the extent to which age is associated with increased severity of chronic lithium poisoning and of which a range of possible factors might explain the associations.Method: We did a retrospective review of patients aged ≥15 years old with serum lithium concentrations ≥1.3 mmol/L from three hospitals. Clinical details, treatment and outcomes were recorded. eGFR, creatinine and lithium clearance were calculated. The severity of lithium toxicity was graded into five categories (Amdisen score). ANOVA was used to quantify the association between age and severity. Spearman correlation coefficient was used to explore relationships between age and different factors expected to alter severity. Ordinal regression analysis was used to determine the interdependence of age and these factors and age on severity of lithium toxicity.Results: From 2008-2018, there were 242 patients with a median age of 56.5 years (IQR: 41-69). There were 156 females (64%). There was a statistically significant association between Amdisen severity scores and age (p = .0004). The median calculated eGFR was 65 mL/min/1.73 m² (IQR: 41-91) with a corresponding estimated lithium clearance of 18 mL/min (IQR: 13.8-22.8). There was no correlation of age with initial serum lithium concentration (p = .76). There was a strong correlation between age and estimated lithium clearance (r = -0.72, 95% CI: -0.78 to -0.66, p < .001), lithium daily dose (r = -0.65, 95% CI: -0.72 to -0.57, p < .0001) and lithium concentration/dose (r = 0.62, 95% CI: 0.53-0.69, p < .0001). There was a weak correlation between age and infection (r = 0.18, 95% CI: 0.04-0.31, p = .009) and drug interactions (r = 0.25, 95% CI: 0.11-0.37, p = .0003). Ordinal regression indicated the independent predictors for severity of lithium toxicity were lithium concentration (p < .0001) and lithium clearance (p = .03) adjusted for age and dose.Conclusions: Despite lower lithium doses, older patients had more severe toxicity. Increased severity of lithium toxicity in the elderly is largely explainable by decreased lithium clearance from multiple factors such as age-related decline in renal function, drug interactions and infection.

Haemodialysis for lithium poisoning: Translating EXTRIP recommendations into practical guidelines

OBJECTIVES

This study aimed to determine the impact on practice of applying the Extracorporeal Treatments in Poisoning (EXTRIP) Workgroup criteria to lithium toxicity.

METHOD

We retrospectively examined the medical records of patients from three hospitals who presented with chronic or acute on chronic lithium poisoning with a lithium concentration ≥1.3 mmol/L (2008-2018). We determined which criteria were met by patients and their subsequent course. We developed and validated a method to predict if lithium concentration would be >1mmol/L at 36 hours.

RESULTS

There were 111 acute on chronic and 250 chronic lithium toxic patients. Nine patients (2.5%) were treated with haemodialysis. Six chronic patients had neurological sequelae. The "estimated lithium concentration at 36 hours > 1 mmol/L" criterion required pharmacokinetic calculations. A simple nomogram was developed using Estimated Glomerular Filtration Rate (eGFR) and lithium concentration. For chronic toxicity, the nomogram would have correctly predicted lithium concentration >1.4 mmol/L at 36 hours in all except two patients. If EXTRIP criteria were followed, dialysis would have been instituted for 211 patients (58%). However, only 51 patients with chronic toxicity fulfilled both a concentration and a clinical criterion. Late neurological sequelae were observed in five out of six patients who fulfilled a concentration and a clinical criterion on admission, with the sixth meeting these criteria shortly after admission.

CONCLUSIONS

The EXTRIP criteria are too broad, but minor modifications allow haemodialysis to be targeted to those most at risk of sequelae. Most acute on chronic poisonings do not need haemodialysis, but it might shorten hospital stay in those with very high concentrations. The nomogram accurately predicts the fall in lithium concentration for chronic poisoning.

Lithium neurotoxicity presenting as dementia with therapeutic serum lithium levels

After 25 years of continuous lithium therapy, a woman with moderate intellectual disability and bipolar disorder developed symptoms suggestive of dementia. In fact, she had developed lithium neurotoxicity, but this was overlooked for 18 months as serial lithium levels were in the therapeutic range.

Clinical Pharmacokinetics in Kidney Disease: Fundamental Principles

Kidney disease is an increasingly common comorbidity that alters the pharmacokinetics of many drugs. Prescribing to patients with kidney disease requires knowledge about the drug, the extent of the patient's altered physiology, and pharmacokinetic principles that influence the design of dosing regimens. There are multiple physiologic effects of impaired kidney function, and the extent to which they occur in an individual at any given time can be difficult to define. Although some guidelines are available for dosing in kidney disease, they may be on the basis of limited data or not widely applicable, and therefore, an understanding of pharmacokinetic principles and how to apply them is important to the practicing clinician. Whether kidney disease is acute or chronic, drug clearance decreases, and the volume of distribution may remain the same or increase. Although in CKD, these changes progress relatively slowly, they are dynamic in AKI, and recovery is possible depending on the etiology and treatments. This, and the use of kidney replacement therapies further complicate attempts to quantify drug clearance at the time of prescribing and dosing in AKI. The required change in the dosing regimen can be estimated or even quantitated in certain instances through the application of pharmacokinetic principles to guide rational drug dosing. This offers an opportunity to provide personalized medical care and minimizes adverse drug events from either under- or overdosing. We discuss the principles of pharmacokinetics that are fundamental for the design of an appropriate dosing regimen in this review.

The 'SILENT Alarm': When History Taking Reveals a Potentially Fatal Toxicity

Introduction

The combination of acute/sub-acute neurological and metabolic derangements should always raise the suspicion of toxicity, either endogenous or exogenous. The adverse effects of psychiatric medications are especially difficult to determine since the psychiatric background of patients is often inaccessible.

Clinical Presentation

A 66-year-old man presented to the emergency department with dysarthria and uncontrolled tremor, rapidly deteriorating into a complex of severe neurological and metabolic derangements. Only after repeated attempts to take a thorough history was lithium toxicity identified.

Conclusion

Thorough, comprehensive history taking, including chronic medications and their substitutes, is essential and lifesaving when potentially lethal medications are involved.

LEARNING POINTS

Outcomes of patient education practices to optimize the safe use of lithium: A literature review

Introduction:

Lithium is commonly used to treat various psychiatric disorders and is particularly effective in the maintenance phase of bipolar disorder. Unfortunately, this drug has a narrow therapeutic index and, if not monitored regularly, can result in toxicity. Therefore, for lithium to be prescribed safely, clinicians must ensure that patients are well educated on lithium toxicity, its prevention, and symptom recognition. This article summarizes studies that investigated lithium education strategies to help promote the safe use of lithium.

Methods:

Four electronic databases were searched using key terms and subject headings. Reference lists of relevant papers were also reviewed. The search was limited to literature published in English, without year limits. Eligible studies examined lithium patient education and the impact on patients' knowledge of safe lithium use.

Results:

Of a total of 517 citations that were retrieved from the electronic database search, 12 were selected for inclusion in this review. Most of the studies included assessed the effect of lithium education on various aspects of patients' knowledge, including but not limited to, lithium toxicity. Of the studies assessing the correlation between lithium knowledge and lithium levels, most demonstrated a positive correlation between lithium knowledge and lithium levels that were more stable and within the higher end of the recommended therapeutic range.

Conclusions:

Studies evaluating lithium patient education and its effect on improving the safe use of lithium are limited. Nevertheless, this literature review highlights that lithium patient education is critical to promote its safe use.

Lithium: one drug, five complications

Background

Lithium poisoning could trigger multiple complications. We report the case of a lithium poisoning with five complications that are described for the first time together.

Case report

A 60-year-old woman was admitted in our intensive care unit for altered consciousness. Severe lithium intoxication was diagnosed (lithium plasmatic level 8.21 mmol/l) associated with acute oliguric kidney failure. Continuous renal replacement therapy was started immediately. Orotracheal intubation was quickly required because of status epilepticus. Medullary aplasia happened 48 h after the patient was intubated. Infectious and immunological causes were ruled out and lithium poisoning was considered as the most likely etiology. Iterative blood and platelet transfusion were required. Severe polyneuropathy was diagnosed on the 5th day after admission. The patient showed a peripheral tetraparesia and cranial nerve failure while lithium plasmatic level had decreased to a therapeutic level. Conversely, urine output increased and hypernatremia promptly occurred, which led to diabetes insipidus diagnosis. Neuropathy decreased in 72 h and the patient was definitely extubated by the 11th day. Hematologic disturbances decreased and no blood transfusion would be required after the 8th day. The patient would keep sequellas of the poisoning. Thin motricity would still be altered and polyuria would remain. Diffuse alopecia was promptly observed, with no iron deficiency or thyroid disturbance.

Conclusion

In addition to presenting this case report, we herein discuss the drug causality, the consequences, and the plausible pathophysiology of these five situations.

Lithium overdose and delayed severe neurotoxicity: timing for renal replacement therapy and restarting of lithium

This is a case report of a man in his 60s who presented to an English hospital following a significant lithium overdose. He was monitored for 24 hours, and then renal replacement therapy was initiated after assessment by the renal team. As soon as the lithium level returned to normal therapeutic levels (from 4.7 mEq/L to 0.67 mEq/L), lithium was restarted by the medical team. At this point, the patient developed new slurred speech and later catatonia. In this case report, we discuss the factors that could determine which patients are at risk of neurotoxicity following lithium overdose and the appropriate decision regarding when and how to consider initiation of renal replacement therapy and restarting of lithium.

Atypical permanent neurological sequelae after an acute intoxication with lithium and aripiprazole

OBJECTIVES

The aim of the present case report was to describe atypical neurological sequelae after a lithium and aripiprazole co-intoxication in a suicide attempt.

METHODS

We report the case of a 31-year-old patient with bipolar disorder who developed, after lithium and aripiprazole massive ingestion, a severe pseudobulbar dysarthria and motor disorders suggestive of basal ganglia micro lesions. We review literature on neurological sequelae due to acute lithium intoxications.

RESULTS

Acute lithium intoxication can cause permanent neurological sequelae, the most frequent clinical feature being a permanent cerebellar syndrome. Moreover, the widely-prescribed combination of lithium with antipsychotics increases the neurotoxicity in lithium intoxications. In this case, both atypical neurological syndrome and normal paraclinical investigations lead first to misdiagnose the lithium neurological damages.

CONCLUSIONS

This case illustrates that acute lithium intoxications can result in serious and potentially permanent neurological deficits, which remain difficult to diagnose. Imaging abnormalities are not constant, and neurological presentation can be atypical.

Lithium Poisoning

Lithium is a commonly prescribed treatment for bipolar affective disorder. However, treatment is complicated by lithium’s narrow therapeutic index and the influence of kidney function, both of which increase the risk of toxicity. Therefore, careful attention to dosing, monitoring, and titration is required. The cause of lithium poisoning influences treatment and 3 patterns are described: acute, acute-on-chronic, and chronic. Chronic poisoning is the most common etiology, is usually unintentional, and results from lithium intake exceeding elimination. This is most commonly due to impaired kidney function caused by volume depletion from lithium-induced nephrogenic diabetes insipidus or intercurrent illnesses and is also drug-induced. Lithium poisoning can affect multiple organs; however, the primary site of toxicity is the central nervous system and clinical manifestations vary from asymptomatic supratherapeutic drug concentrations to clinical toxicity such as confusion, ataxia, or seizures. Lithium poisoning has a low mortality rate; however, chronic lithium poisoning can require a prolonged hospital length of stay from impaired mobility and cognition and associated nosocomial complications. Persistent neurological deficits, in particular cerebellar, are described and the incidence and risk factors for its development are poorly understood, but it appears to be uncommon in uncomplicated acute poisoning. Lithium is readily dialyzable, and rationale support extracorporeal treatments to reduce the risk or the duration of toxicity in high-risk exposures. There is disagreement in the literature regarding factors that define patients most likely to benefit from treatments that enhance lithium elimination, including specific plasma lithium concentration thresholds. In the case of extracorporeal treatments, there are observational data in its favor, without evidence from randomized controlled trials (none have been performed), which may lead to conservative practices and potentially unnecessary interventions in some circumstances. More data are required to define the risk–benefit of extracorporeal treatments and their use (modality, duration) in the management of lithium poisoning.

Does lower urine-specific gravity predict decline in renal function and hypernatremia in older adults exposed to psychotropic medications? An exploratory analysis

BACKGROUND

Exposure to psychotropic agents, including lithium, antipsychotics and antidepressants, has been associated with nephrogenic diabetes insipidus (NDI). This is especially concerning in older adults already at risk of developing chronic kidney disease (CKD) and hypernatremia with advanced aging. This study investigates whether commonly performed random urine-specific gravity (USG) tests can predict adverse NDI outcomes (CKD and hypernatremia) in psychotropic-exposed older adults.

METHODS

This was a retrospective longitudinal study of 173 geriatric psychiatry patients (age ≥65 years) exposed to psychotropic medications. Our main continuous outcome was 'decrease in estimated glomerular filtration rate (eGFR) >10 mL/min/1.73 m(2)' over 5-year follow-up. Hypernatremia and acute kidney injury (AKI) were secondary outcomes. Whether baseline USG <1.010 predicted outcomes was assessed in bivariate and multivariate analyses.

RESULTS

USG <1.010 predicted hypernatremia episodes (sodium concentration ≥150 mmol/L-28.1 versus 12%, χ(2) = 4.7, P = 0.03). USG <1.010 [odds ratio 2.36 (95% confidence interval 0.93-6.0), P = 0.07], baseline eGFR and typical antipsychotic use independently predicted decrease in eGFR >10 mL/min/1.73 m(2). Patients with a single baseline sodium concentration of ≥140 mmol/L and USG <1.010 have a 26.3% incidence of AKI and a 57.9% incidence of hypernatremia over the ensuing 5 years.

CONCLUSIONS

In psychotropic-exposed older adults, there appears to be a clinically important association between low USG and developing both hypernatremia and CKD. USG may be a useful surrogate measure for NDI-related outcomes in large administrative database studies, where ideal measures such as 24-h urine volume may not be available.

An examination of myth: a favorable cardiovascular risk-benefit analysis of high-dose thyroid for affective disorders

INTRODUCTION

High dose thyroid (HDT) is included in major treatment guidelines for the treatment of bipolar disorders. Yet it is seldom used partly based on perceived cardiovascular risks. The cardiovascular risks of HDT are examined.

METHODS

A literature search was conducted for the cardiovascular risks of HDT and for comparisons sake psychiatric medications. Case reports of atrial fibrillation (afib) associated with HDT are reported.

RESULTS

While hyperthyroidism is a significant cardiovascular risk factor causing a 20% premature death rate, HDT treatment does not appear to be of significant cardiovascular risk. HDT differs from hyperthyroidism in significant ways. The sequela of hyperthyroidism are increasingly tied to autoimmune complications which are absent with HDT. Equating hyperthyroidism with HDT is incorrect. The five case reports of HDT treatment associated with afib were potentially caused by other factors. If HDT increases the risks of afib, monitoring for afib would minimizes the risk. Even in overt hyperthyroidism the risk of other arrhythmias are minimal. When compared to many psychiatric medications HDT is as safe or safer.

LIMITATIONS

There are no direct studies of cardiovascular risks of HDT for affective patients. High tolerance of a medication does not necessarily imply lack of risk. The five case reports were spontaneous, other cases may not have been reported.

CONCLUSION

The cardiovascular risks of HDT appear to be low. HDT is at least as safe as or safer than many psychiatric medications. It is effective and well tolerated.

Extracorporeal Treatment for Lithium Poisoning: Systematic Review and Recommendations from the EXTRIP Workgroup

The Extracorporeal Treatments in Poisoning Workgroup was created to provide evidence-based recommendations on the use of extracorporeal treatments in poisoning. Here, the EXTRIP workgroup presents its recommendations for lithium poisoning. After a systematic literature search, clinical and toxicokinetic data were extracted and summarized following a predetermined format. The entire workgroup voted through a two-round modified Delphi method to reach a consensus on voting statements. A RAND/UCLA Appropriateness Method was used to quantify disagreement, and anonymous votes were compiled and discussed in person. A second vote was conducted to determine the final workgroup recommendations. In total, 166 articles met inclusion criteria, which were mostly case reports, yielding a very low quality of evidence for all recommendations. A total of 418 patients were reviewed, 228 of which allowed extraction of patient-level data. The workgroup concluded that lithium is dialyzable (Level of evidence=A) and made the following recommendations: Extracorporeal treatment is recommended in severe lithium poisoning (1D). Extracorporeal treatment is recommended if kidney function is impaired and the [Li(+)] is >4.0 mEq/L, or in the presence of a decreased level of consciousness, seizures, or life-threatening dysrhythmias irrespective of the [Li(+)] (1D). Extracorporeal treatment is suggested if the [Li(+)] is >5.0 mEq/L, significant confusion is present, or the expected time to reduce the [Li(+)] to <1.0 mEq/L is >36 hours (2D). Extracorporeal treatment should be continued until clinical improvement is apparent or [Li(+)] is <1.0 mEq/L (1D). Extracorporeal treatments should be continued for a minimum of 6 hours if the [Li(+)] is not readily measurable (1D). Hemodialysis is the preferred extracorporeal treatment (1D), but continuous RRT is an acceptable alternative (1D). The workgroup supported the use of extracorporeal treatment in severe lithium poisoning. Clinical decisions on when to use extracorporeal treatment should take into account the [Li(+)], kidney function, pattern of lithium toxicity, patient's clinical status, and availability of extracorporeal treatments.

Minimizing negative outcomes associated with potentially harmful lithium levels by means of pharmacist-led educational interventions in an inpatient psychiatric facility

Introduction: Studies examining educational interventions led by pharmacists to minimize negative outcomes associated with elevated and potentially harmful lithium levels in inpatient psychiatric facilities are lacking. Other studies indicate a need for improvement of therapeutic drug monitoring for lithium. The aim of this article is to identify potential improvements in negative outcomes associated with harmful lithium blood levels after educational interventions are delivered by a clinical pharmacist to providers of an inpatient psychiatric facility.

Methods: Medication reports were queried from the pharmacy database to identify all patients who were taking lithium within 1 year. Laboratory results, physician progress notes, nursing progress notes, and treatment plans were studied to detect any adverse events associated with lithium levels. Educational interventions created by pharmacy services were tailored toward medical staff and delivered over a 3 month period. Learning was assessed at pre-educational and posteducational interventions.

Results: One hundred fifteen patients received lithium between March 2012 and March 2013. The most-frequent adverse effects reported associated with lithium included tremor, dizziness, slurred speech, and lethargy. Two patients were sent to the local emergency department for lithium toxicity and required dialysis. Fifty-two patients received lithium after educational interventions, and no adverse events were reported. A lithium drug-monitoring spreadsheet was created for pharmacy use, and drug-monitoring guidelines were revised and disseminated throughout the facility.

Discussion: A reduction in negative outcomes associated with lithium was noted after educational interventions to medical staff occurred. The impact of pharmacist-led educational interventions demonstrated a high potential for success.

The McGill Geriatric Lithium-Induced Diabetes Insipidus Clinical Study (McGLIDICS)

OBJECTIVE

Despite being a common and potentially serious condition, nephrogenic diabetes insipidus (NDI) remains poorly understood in older lithium users. Our main objective was to compare the prevalence of NDI symptoms and decreased urine osmolality ([UOsm] < 300 milli-Osmoles [mOsm/kg]) among geriatric and adult lithium users. We also assessed NDI symptoms, serum sodium (Na+), and urine specific gravity (USG) as possible surrogate measures of decreased UOsm, and ascertained whether potential etiologic factors independently correlated with decreased UOsm.

METHOD

This was a cross-sectional study of 100 consecutive outpatients treated with lithium from 6 tertiary care clinics, of which 45 were geriatric (aged 65 years and older) and 55 adult (aged 18 to 64 years). Patients completed a symptom questionnaire and underwent laboratory tests, including UOsm, serum Na+, and USG.

RESULTS

Geriatric and adult lithium users had similar rates of decreased UOsm (12.5%, compared with 17.9%, P = 0.74), but geriatric patients reported less symptoms (P < 0.05). Although UOsm did not correlate with symptoms or current serum Na+, USG of less than 1.010 was suggestive of UOsm of less than 300 mOsm/kg. Age, lithium duration, and serum lithium level were independently associated with UOsm.

CONCLUSIONS

The prevalence of decreased UOsm is similar in geriatric and adult lithium users, but older patients are less likely to report urinary and thirst symptoms. Although subjective symptoms do not correlate with UOsm, USG may be a cost-efficient clinical surrogate measure for UOsm. We suggest clinicians increase their vigilance for decreased UOsm, especially in lithium users with advanced age, longer duration of lithium exposure, and higher lithium levels. This may potentially prevent lithium intoxication, falls, hypernatremic events, and renal dysfunction.

Renal failure in lithium-treated bipolar disorder: a retrospective cohort study

Objective

Lithium users are offered routine renal monitoring but few studies have quantified the risk to renal health. The aim of this study was to assess the association between use of lithium carbonate and incidence of renal failure in patients with bipolar disorder.

Methods

This was a retrospective cohort study using the General Practice Research Database (GPRD) and a nested validation study of lithium exposure and renal failure. A cohort of 6360 participants aged over 18 years had a first recorded diagnosis of bipolar disorder between January 1, 1990 and December 31, 2007. Data were examined from electronic primary care records from 418 general practices across the UK. The primary outcome was the hazard ratio for renal failure in participants exposed to lithium carbonate as compared with non-users of lithium, adjusting for age, gender, co-morbidities, and poly-pharmacy.

Results

Ever use of lithium was associated with a hazard ratio for renal failure of 2.5 (95% confidence interval 1.6 to 4.0) adjusted for known renal risk factors. Absolute risk was age dependent, with patients of 50 years or older at particular risk of renal failure: Number Needed to Harm (NNH) was 44 (21 to 150).

Conclusions

Lithium is associated with an increased risk of renal failure, particularly among the older age group. The absolute risk of renal failure associated with lithium use remains small.

Acute Atrial Fibrillation as an Unusual Form of Cardiotoxicity in Chronic Lithium Overdose

Lithium overdose primarily results in neurologic toxicity; however a number of important cardiac side effects have previously been reported, including nonspecific T-wave changes, ST-segment changes, QTc prolongation, sinus node dysfunction, atrioventricular blocks and ventricular dysrhythmias. Atrial fibrillation due to such toxicity is very uncommon. The current paper describes a patient who developed acute atrial fibrillation due to chronic lithium overdose.

Nitrergic, glutamatergic and gabaergic systems in lithium toxicity

We examined the role of nitrergic, glutamatergic and gamma-aminobutyric acid (GABA)-ergic systems in the mechanism(s) underlying lithium induced acute toxicity. With this aim, lithium (18 mEq/kg, i.p.) intoxicated rats were observed for 3 hr recording their clinical signs and death. Lithium exposure at the dose used produced central nervous system (CNS) depression. Pre-treatment of N(w)-nitro-L-arginine methyl ester (L-NAME) a nonselective nitric oxide synthase inhibitor (10 mg/kg, i.p.), 7-nitroindazole (7-NI) a selective neuronal nitric oxide synthase inhibitor (25 mg/kg, i.p.), nitric oxide precursor L-arginine (1,000 mg/kg, i.p.) and MK-801 a noncompetitive antagonist of N-methyl-D-aspartic acid class of glutamate receptors (0.5 mg/kg, i.p.) all increased CNS depression and mortality in lithium group however, no change was seen in GABA receptor agonist GABA (1,000 mg/kg, i.p.) or D-arginine (1,000 mg/kg, i.p.) a biologically inactive enantiomer of L-arginine pre-treated rats. Glutamic acid decarboxylase (GAD) enzyme activity was measured in hippocampus, cerebral cortex and cerebellum of the different groups of animals. GAD enzyme activity reduced in cerebral cortex but not altered in hippocampus or cerebellum by lithium as compared to the control (saline) group. We conclude that an interaction with nitrergic and glutamatergic systems may have a role in the acute toxicity of lithium in rats.The inhibition of glutamate metabolism may arise from this interaction and the involvement of GABA-ergic system should be further investigated in this toxicity.

Mutations in the AVPR2, AVP-NPII, and AQP2 genes in Turkish patients with diabetes insipidus

The aim of this study was to identify mutations in three different genes, the arginine-vasopressin-neurophysin II (AVP-NPII) gene, the arginine-vasopressin receptor 2 (AVPR2) gene, and the vasopressin-sensitive water channel aquaporin-2 (AQP2) gene in Turkish patients affected by central diabetes insipidus or nephrogenic diabetes insipidus. This study included 15 patients from unrelated families. Prospective clinical data were collected for all patients including the patients underwent a water deprivation-desmopressin test. The coding regions of the AVPR2, AQP2, and AVP-NPII genes were amplified by polymerase chain reaction and submitted to direct sequence analysis. Of the 15 patients with diabetes insipidus referred to Gulhane Military Medical Academy, Department of Endocrinology and Metabolism, eight patients have AVPR2 mutations, five patients have AQP2 mutations and two patients have AVP-NPII mutations. Of the patients, which have AVPR2 mutations, one is compound heterozygous for AVPR2 gene. Seven of these mutations are novel. Comparison of the clinical outcomes of these mutations may facilitate in understanding the functions of AVP-NPII, AQP2, and AVPR2 genes in future studies.

The effects of lithium on renal function in older adults--a systematic review

Chronic renal failure (CRF) and nephrogenic diabetes insipidus (NDI) are potential consequences of chronic lithium use, while acute renal failure (ARF) has been described in lithium intoxication. We performed a systematic review of all studies pertaining to the effects of lithium on the kidney in older adults. The ARF incidence was 1.5% per person-year and concurrent loop diuretic and angiotensin-converting enzyme inhibitor use with lithium increased the risk. The CRF prevalence estimates varied from 1.2% to 34%, with risk factors including age, previous lithium intoxication, polyuria, previously impaired renal function, and decreased maximal urine osmolality. The prevalence of NDI varied widely from 1.8%  to 85%. Risk factors included lithium duration, dose, level, slow-release formulation, and clinical nonresponse. Except for amiloride use in NDI, there is little evidence for treatment of other lithium-induced adverse renal effects. Currently, there is no compelling evidence to suggest that lithium should be avoided in elderly patients for fear of renal side effects.

The science and practice of lithium therapy

INTRODUCTION

Despite more that 60 years of clinical experience, the effective use of lithium for the treatment of mood disorder, in particular bipolarity, is in danger of becoming obsolete. In part, this is because of exaggerated fears surrounding lithium toxicity, acute and long-term tolerability and the encumbrance of life-long plasma monitoring. Recent research has once again positioned lithium centre stage and amplified the importance of understanding its science and how this translates to clinical practice.

OBJECTIVE

The aim of this paper is to provide a sound knowledge base as regards the science and practice of lithium therapy.

METHOD

A comprehensive literature search using electronic databases was conducted along with a detailed review of articles known to the authors pertaining to the use of lithium. Studies were limited to English publications and those dealing with the management of psychiatric disorders in humans. The literature was synthesized and organized according to relevance to clinical practice and understanding.

RESULTS

Lithium has simple pharmacokinetics that require regular dosing and monitoring. Its mechanisms of action are complex and its effects are multi-faceted, extending beyond mood stability to neuroprotective and anti-suicidal properties. Its use in bipolar disorder is under-appreciated, particularly as it has the best evidence for prophylaxis, qualifying it perhaps as the only true mood stabilizer currently available. In practice, its risks and tolerability are exaggerated and can be readily minimized with knowledge of its clinical profile and judicious application.

CONCLUSION

Lithium is a safe and effective agent that should, whenever indicated, be used first-line for the treatment of bipolar disorder. A better understanding of its science alongside strategic management of its plasma levels will ensure both wider utility and improved outcomes.

Reformulation of current recommendations for target serum lithium concentration according to clinical indication, age and physical comorbidity

BACKGROUND

There have been significant changes in the nature of psychiatric patient populations and patterns of drug prescribing in mood disorders since serum lithium monitoring was introduced. It seems opportune to review current guidelines for target lithium concentration given the decline in lithium monotherapy and increase in the numbers of older people and those with comorbid physical disease administered lithium.

METHOD

A review was made of the literature of lithium monitoring and target serum concentration in mood disorders, older people, and comorbid physical illness.

RESULTS

Current guidelines, which generally recommend a target serum concentration of 0.5/0.6 to 1.1/1.2 mmol/L, have a number of limitations. A target lithium level of > 0.8 mmol/L is inappropriate given poor tolerability, and adequate efficacy when combination lithium-antipsychotic therapy is used at this or lower levels. Guidelines have largely failed to match specific clinical indications to serum levels, and to consider comorbid physical illness factors known to be associated with lithium toxicity.

CONCLUSION

For most patients, a target serum lithium concentration range of 0.5-0.8 mmol/L, varying according to clinical indication, age and concurrent physical status, seems most appropriate in enhancing efficacy and minimizing adverse effects. The lower end of this range (0.5-0.6 mmol/L) is recommended for patients 50 years and over; those with diabetes insipidus, renal impairment or thyroid dysfunction; those administered diuretics, angiotensin converting enzyme (ACE) inhibitors or non-steroidal anti-inflammatory drugs (NSAIDs)/COX-2 inhibitors; and in the prophylaxis of bipolar depression and management of acute unipolar depression. The higher end of this range (0.7-0.8 mmol/L) is recommended in the management of acute mania and prophylaxis of mania.

The lithiumeter: a measured approach

BACKGROUND

Lithium has long been recognised for its mood-stabilizing effects in the management of bipolar disorder (BD) but in practice its use has been limited because of real and 'imagined' concerns. This article addresses the need for lithium to be measured with respect to its clinical and functional effects. It introduces a visual scale, termed lithiumeter, which captures the optimal lithium plasma levels for the treatment of BD.

METHODS

  Key words pertaining to lithium's administration, dosing, and side effects as well as its efficacy in acute and long-term treatment of BD were used to conduct an electronic search of the literature. Relevant articles were identified by the authors and reviewed.

RESULTS

This paper outlines the considerations necessary prior to initiating lithium therapy and provides a guide to monitoring lithium plasma levels. Current recommendations for optimal plasma lithium levels in the management of BD are then discussed with respect to indications for use in the acute phases of the illness and maintenance therapy. The risks associated with lithium treatment are also discussed.

CONCLUSIONS

The lithiumeter provides a practical guide of optimal lithium levels for the clinical management of BD.

Optimal frequency of lithium administration in the treatment of bipolar disorder: clinical and dosing considerations

Bipolar disorder is a recurrent chronic illness distinguished by periods of mania and depression. Lithium has been used for about 60 years as a 'mood stabilizer' for bipolar disorder with proven efficacy in preventing relapse of both mania and depression. Despite its long history and ongoing use in current management of bipolar disorder, the optimal dosing of lithium is still the subject of ongoing debate. This article aims to evaluate different dosing schedules, in the light of the unique pharmacokinetic and pharmacodynamic properties of lithium, as well as its adverse-effect and toxicity profiles. This is all the more important given the narrow therapeutic index of lithium. Current recommendations mostly advocate that lithium be administered in multiple daily doses. However, single daily or alternate daily schedules may be viable options for administration. Multiple daily schedules are thought to be advantageous in maintaining more constant plasma lithium concentrations than single daily regimens, which are associated with significant fluctuations throughout the day. When comparing these two schedules with respect to plasma lithium concentrations, adverse-effect profiles and recurrence of symptoms, there are no significant differences between the two regimens. In fact, a single daily regimen may have added advantages in reducing the risk of long-term renal damage and increasing compliance. The evidence for alternate daily dosing is somewhat varied with regard to symptom recurrence; however, this schedule has been shown to be associated with decreased adverse effects, and further research into this issue is therefore warranted. Presently, therefore, clinicians should consider single daily administration of lithium to potentially minimize adverse effects and enhance compliance.

Successful treatment of lithium toxicity with sodium polystyrene sulfonate: a retrospective cohort study

CONTEXT

Lithium (Li) is a first-line treatment for bipolar disorder but has a narrow therapeutic index. Treatment of Li toxicity includes supportive measures and hemodialysis in severe cases, but this modality is not always immediately available. Sodium polystyrene sulfonate (SPS, Kayexalate), a cation exchanger, has been promising in animal models and human reports to reduce absorption and enhance elimination of Li.

MATERIAL AND METHODS

A retrospective cohort study was conducted. All cases of chronic Li intoxication were reviewed in two adult-care hospitals from 2000 to 2009. A group comparison and a within-patient comparison were performed to compare the effect of SPS on the median Li half-life (T(1/2)). For this study, at least three serum Li levels were required for T(1/2) calculations.

RESULTS

Forty-eight patients met inclusion requirements, 12 of whom had taken SPS. Median Li T(1/2) in the treated and control groups was 20.5 and 43.2 hours, respectively (p = 0.0006). In the 12 treated patients, Li T(1/2) during SPS was on average 48.9% shorter than without SPS. Furthermore, in one subject in whom urinary Li data were available, Li clearance with SPS was superior to Li renal clearance. Prolonged constipation was noted in one patient whereas mild hypokalemia was noted in six patients treated with SPS.

CONCLUSION

This study shows that SPS reduced Li T(1/2) and suggests that SPS is capable of promoting Li elimination in chronic intoxications. These results warrant a prospective trial looking at the use of SPS in the treatment of Li overdose as an adjunct to supportive measures and hemodialysis.

The International Society for Bipolar Disorders (ISBD) consensus guidelines for the safety monitoring of bipolar disorder treatments

OBJECTIVES

Safety monitoring is an important aspect of bipolar disorder treatment, as mood-stabilising medications have potentially serious side effects, some of which may also aggravate existing medical comorbidities. This paper sets out the International Society for Bipolar Disorders (ISBD) guidelines for the safety monitoring of widely used agents in the treatment of bipolar disorder. These guidelines aim to provide recommendations that take into consideration the balance between safety and cost-effectiveness, to highlight iatrogenic and preventive clinical issues, and to facilitate the broad implementation of therapeutic safety monitoring as a standard component of treatment for bipolar disorder.

METHODS

These guidelines were developed by an ISBD workgroup, headed by the senior author (MB), through an iterative process of serial consensus-based revisions. After this, feedback from a multidisciplinary group of health professionals on the applicability of these guidelines was sought to develop the final recommendations.

RESULTS

General safety monitoring recommendations for all bipolar disorder patients receiving treatment and specific monitoring recommendations for individual agents are outlined.

CONCLUSIONS

These guidelines are derived from evolving and often indirect data, with minimal empirical cost-effectiveness data available to provide guidance. These guidelines will therefore need to be modified to adapt to different clinical settings and health resources. Clinical acumen and vigilance remain critical ingredients for safe treatment practice.

Review of lithium effects on brain and blood

Clinicians have long used lithium to treat manic depression. They have also observed that lithium causes granulocytosis and lymphopenia while it enhances immunological activities of monocytes and lymphocytes. In fact, clinicians have long used lithium to treat granulocytopenia resulting from radiation and chemotherapy, to boost immunoglobulins after vaccination, and to enhance natural killer activity. Recent studies revealed a mechanism that ties together these disparate effects of lithium. Lithium acts through multiple pathways to inhibit glycogen synthetase kinase-3beta (GSK3 beta). This enzyme phosphorylates and inhibits nuclear factors that turn on cell growth and protection programs, including the nuclear factor of activated T cells (NFAT) and WNT/beta-catenin. In animals, lithium upregulates neurotrophins, including brain-derived neurotrophic factor (BDNF), nerve growth factor, neurotrophin-3 (NT3), as well as receptors to these growth factors in brain. Lithium also stimulates proliferation of stem cells, including bone marrow and neural stem cells in the subventricular zone, striatum, and forebrain. The stimulation of endogenous neural stem cells may explain why lithium increases brain cell density and volume in patients with bipolar disorders. Lithium also increases brain concentrations of the neuronal markers n-acetyl-aspartate and myoinositol. Lithium also remarkably protects neurons against glutamate, seizures, and apoptosis due to a wide variety of neurotoxins. The effective dose range for lithium is 0.6-1.0 mM in serum and >1.5 mM may be toxic. Serum lithium levels of 1.5-2.0 mM may have mild and reversible toxic effects on kidney, liver, heart, and glands. Serum levels of >2 mM may be associated with neurological symptoms, including cerebellar dysfunction. Prolonged lithium intoxication >2 mM can cause permanent brain damage. Lithium has low mutagenic and carcinogenic risk. Lithium is still the most effective therapy for depression. It "cures" a third of the patients with manic depression, improves the lives of about a third, and is ineffective in about a third. Recent studies suggest that some anticonvulsants (i.e., valproate, carbamapazine, and lamotrigene) may be useful in patients that do not respond to lithium. Lithium has been reported to be beneficial in animal models of brain injury, stroke, Alzheimer's, Huntington's, and Parkinson's diseases, amyotrophic lateral sclerosis (ALS), spinal cord injury, and other conditions. Clinical trials assessing the effects of lithium are under way. A recent clinical trial suggests that lithium stops the progression of ALS.

Evaluation of available treatment guidelines for the management of lithium intoxication

Intoxications with lithium carry considerable risk for long-term morbidity and even mortality. Consequently, any patient suspected of lithium intoxication requires immediate and appropriate care. The objectives of this study were to assess the completeness and the applicability of generally available treatment guidelines for the management of patients with a lithium intoxication and, hence, to provide general recommendations for improvement of existing treatment guidelines. Nineteen treatment guidelines originating from 7 different countries were gathered by searching the Internet, online databases, and textbooks and by contacting different poison information centers and university medical centers. A list of items was composed from the retrieved treatment guidelines and a further literature search. Most relevant items were present in the various guidelines. However, in some guidelines, essential information was missing or potentially hazardous information was provided. Clarity, presentation, and applicability of the guidelines, as assessed using parts of the Appraisal of Guidelines Research and Evaluation instrument, were relatively poor. Regular updates of treatment guidelines should be performed to incorporate new essential information. To improve applicability of guidelines, unambiguous key recommendations, alternative treatments, and special care requirements should be provided and authors are recommended to test treatment guidelines using a panel of less experienced caregivers in a hypothetical case scenario.

Renal effects of long-term lithium therapy in the elderly: a cross-sectional study

OBJECTIVES

To determine the effect of long-term lithium therapy on glomerular filtration rate (GFR) and maximum renal concentrating capacity (Umax) in the elderly, to identify possible risk factors, to determine the clinical impact of a reduced Umax in this population and in case of polyuria to establish a diagnosis.

METHODS

This is a cross-sectional study with 48 outpatients of 65 years or over (mean 74.8 years), who were treated with lithium for more than 6 months (mean 9.2 years). The GFR was determined with the Cockcroft-Gault formula (GFR-CG) and the Umax was measured in a urine sample collected between 3 and 5 h after the patients received 40 microg desmopressin (DDAVP) intranasally.

RESULTS

No relation was found between duration of lithium treatment and GFR-CG, but there was a significant negative relation between duration of lithium treatment and Umax (B -0.73; CI: -1.249/-0.212); 73% of the patients had a moderate to severe concentrating defect. No other risk factors than duration of lithium therapy were identified. A reduced Umax caused polyuria (>2500 mL/24 h) in 33% but did not cause significant more thirst, incontinence or disturbed sleep.

CONCLUSIONS

In this geriatric population a negative relation was found between duration of lithium treatment and Umax. But a reduced Umax did not result in significant more clinical symptoms. In case of polyuria other mechanisms beside nephrogenic diabetes insipidus were found to play a role in this age group.

Neuroactive steroids, mood stabilizers, and neuroplasticity: alterations following lithium and changes in Bcl-2 knockout mice

Many neuroactive steroids (NS) demonstrate neurotrophic and neuroprotective actions, including protection against apoptosis via Bcl-2 protein. NS are altered in post-mortem brain tissue from subjects with bipolar disorder, and several agents with efficacy in mania elevate NS in rodents. We therefore hypothesized that lithium and valproate may elevate NS, and compensatory NS increases may occur in Bcl-2 knockout mice. NS levels (allopregnanolone, pregnenolone) were determined in frontal cortex by negative ion chemical ionization gas chromatography/mass spectrometry in male Wistar Kyoto rats treated chronically with lithium, valproate, or vehicle. NS were also investigated in heterozygous Bcl-2 knockout mice. Allopregnanolone levels are significantly elevated in lithium-treated (p<0.05), but not in valproate-treated, rats. Pregnenolone levels also tend to be higher following lithium treatment (p=0.09). Knockout of Bcl-2 significantly increases pregnenolone levels in mice (p<0.01), while allopregnanolone levels are unaltered. NS induction may be relevant to mechanisms contributing to lithium therapeutic efficacy and neuroprotection.