Lithium administered to pregnant, lactating and neonatal rats: entry into developing brain.

BACKGROUND: Little is known about the extent of drug entry into developing brain, when administered to pregnant and lactating women. Lithium is commonly prescribed for bipolar disorder. Here we studied transfer of lithium given to dams, into blood, brain and cerebrospinal fluid (CSF) in embryonic and postnatal animals as well as adults. METHODS: Lithium chloride in a clinically relevant dose (3.2 mg/kg body weight) was injected intraperitoneally into pregnant (E15-18) and lactating dams (birth-P16/17) or directly into postnatal pups (P0-P16/17). Acute treatment involved a single injection; long-term treatment involved twice daily injections for the duration of the experiment. Following terminal anaesthesia blood plasma, CSF and brains were collected. Lithium levels and brain distribution were measured using Laser Ablation Inductively Coupled Plasma-Mass Spectrometry and total lithium levels were confirmed by Inductively Coupled Plasma-Mass Spectrometry. RESULTS: Lithium was detected in blood, CSF and brain of all fetal and postnatal pups following lithium treatment of dams. Its concentration in pups' blood was consistently below that in maternal blood (30-35%) indicating significant protection by the placenta and breast tissue. However, much of the lithium that reached the fetus entered its brain. Levels of lithium in plasma fluctuated in different treatment groups but its concentration in CSF was stable at all ages, in agreement with known stable levels of endogenous ions in CSF. There was no significant increase of lithium transfer into CSF following application of Na+/K+ ATPase inhibitor (digoxin) in vivo, indicating that lithium transfer across choroid plexus epithelium is not likely to be via the Na+/K+ ATPase mechanism, at least early in development. Comparison with passive permeability markers suggested that in acute experiments lithium permeability was less than expected for diffusion but similar in long-term experiments at P2. CONCLUSIONS: Information obtained on the distribution of lithium in developing brain provides a basis for studying possible deleterious effects on brain development and behaviour in offspring of mothers undergoing lithium therapy.

Effect of Experimental Fanconi Syndrome on Tubular Reabsorption of Lithium in Rats.

Lithium, administered to patients of bipolar disorders, is mainly excreted into urine, and tubular reabsorption at the proximal tubule is involved in the renal handling of lithium. In this study, we examined the renal excretion of lithium in rats with Fanconi syndrome, characterized by defects of transports of various compounds at the proximal tubules, induced by maleic acid. After maleic acid was intravenously injected, mannitol and lithium chloride were infused in turn. Using samples of plasma and bladder urine during the mannitol infusion, renal parameters were determined. Pharmacokinetic parameters of lithium were obtained using samples during the lithium chloride infusion. Maleic acid decreased creatinine clearance and increased the fractional excretion of glucose and phosphate, suggesting the induction of Fanconi syndrome. In rats with Fanconi syndrome, plasma concentration of lithium was increased, and its renal clearance was decreased. No effect on the fractional excretion of lithium was exhibited. This study represents that the tubular reabsorption of lithium was impaired to the same degree with glomerular filtration in rats with experimental Fanconi syndrome and that the dysfunction of the tubular reabsorption of glucose and phosphate was more severe. It is possible that Fanconi syndrome inhibited the reabsorption of lithium at the proximal tubule and facilitated the reabsorption of lithium from the loop of Henle to the collecting duct.

A reappraisal of the role of fever in the occurrence of neurological sequelae following lithium intoxication: a systematic review.

INTRODUCTION: We aimed to review cases of Syndrome of Irreversible Lithium-Effectuated Neurotoxicity (SILENT) characterized by neurological sequelae following acute lithium toxicity and to explore whether cerebellar sequelae are more frequent in cases presenting with fever and/or infection. AREAS COVERED: Case reports were identified from: (i) 6 reviews published up to 2005; (ii) MEDLINE, Web of Sciences, Cochrane Library and PsycINFO search. EXPERT OPINION: We identified 123 SILENT cases published from 1965 to 2019, in which cerebellar sequelae were observed in an overwhelming proportion (79%). SILENT may occur at any time during lithium treatment. This complication is most frequently observed during routine lithium treatment, with fewer than 10% of cases occurring after accidental or intentional overdoses. SILENT may occur even when lithium plasma levels are within the therapeutic range: 63% of cases had lithium plasma level <2.5 mEq/l (low/mild toxicity). Fever and/or infection were reported in nearly half of the patients (48%). The likelihood of presenting with cerebellar vs. other neurological sequelae was independently increased by elevated plasma lithium level (≥ 2.5 mEq/l) and by a history of fever and/or infection. Lithium users should be warned of the need to consult in case of fever to adjust their lithium dosage.

The role of brain barriers in the neurokinetics and pharmacodynamics of lithium.

Lithium (Li) is the most widely used mood stabilizer in treating patients with bipolar disorder. However, more than half of the patients do not or partially respond to Li therapy, despite serum Li concentrations in the serum therapeutic range. The exact mechanisms underlying the pharmacokinetic-pharmacodynamic (PK-PD) relationships of lithium are still poorly understood and alteration in the brain pharmacokinetics of lithium may be one of the mechanisms explaining the variability in the clinical response to Li. Brain barriers such as the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSFB) play a crucial role in controlling blood-to-brain and brain-to-blood exchanges of various molecules including central nervous system (CNS) drugs. Recent in vivo studies by nuclear resonance spectroscopy revealed heterogenous brain distribution of Li in human that were not always correlated with serum concentrations, suggesting regional and variable transport mechanisms of Li through the brain barriers. Moreover, alteration in the functionality and integrity of brain barriers is reported in various CNS diseases, as a cause or a consequence and in this regard, Li by itself is known to modulate BBB properties such as the expression and activity of various transporters, metabolizing enzymes, and the specialized tight junction proteins on BBB. In this review, we will focus on recent knowledge into the role of the brain barriers as key-element in the Li neuropharmacokinetics which might improve the understanding of PK-PD of Li and its interindividual variability in drug response.

Pharmacotherapy for depression and bipolar disorder during lactation: A framework to aid decision making.

OBJECTIVE: Breastmilk is recommended as the exclusive source of nutrition for infants younger than 6 months due to the numerous health benefits for both infants and mothers. Although many women are prescribed medications during pregnancy and postpartum, limited data are available to assist women in weighing the benefits compared to the risks of peripartum medication use. The goals of this paper are to discuss the importance of breastmilk for the health of both the mother and infant, evaluate the impact of medication use on women's infant feeding choice, describe the transfer of drugs to breastmilk and infants, and provide a framework for clinicians to support evidence-based counseling for women treated for mood disorders. RECOMMENDATIONS: We recommend early pregnancy counseling to discuss the benefits and risks of medications during breastfeeding. The Surgeon General's Call to Action (2011) highlights the short and long-term negative health effects of not providing breastmilk. Integrating recommendations from the pediatric and obstetric teams allows patients to make decisions based on evidence and reach their infant feeding goals. Databases containing summaries of research findings and pharmacologic properties of the drug of interest are an essential resource for clinicians.

Psychotropic drug use in perinatal women with bipolar disorder.

Optimal dose management of psychotropic drugs during the perinatal period reduces the risk for recurrence of mood episodes in women with Bipolar Disorder. Physiological changes during pregnancy are associated with decreases in the plasma concentrations of the majority of mood stabilizing medications. Regular symptom and drug concentration monitoring for lithium and anticonvulsants with reflexive dose adjustment improves the probability of sustained symptom remission across pregnancy. The elimination clearance trajectory across pregnancy for psychotropics dictates the frequency of laboratory monitoring and dose adjustment. The literature on the pharmacokinetics of lithium, lamotrigine, carbamazepine and atypical antipsychotics during pregnancy and postpartum are reviewed, recommendations for symptom and laboratory monitoring are proposed and recommendations for dose adjustments are presented.

Treatment of the obsessive-compulsive and bipolar disorders comorbidity: pharmacodynamic and pharmacokinetic evaluation.

Introduction: The comorbidity between obsessive-compulsive disorder (OCD) and bipolar disorders (BDs) is a frequent and severe condition characterized by a chronic course, high suicidal risk and tendency towards chronicity and treatment non-response. It represents a real challenge to psychiatrists, while requiring a careful and appropriate therapeutic management consisting in the combination of serotonergic antidepressants (ADs), such as serotonin reuptake inhibitors (SRIs), with mood stabilizers. This combination, like any other, raises the problems related to drug interactions that may lead to pharmacokinetic and pharmacodynamic changes, resulting in the modification of the pharmacologic effect and safety profile of a given compound. Areas covered: The aim of the present paper was to review the literature on the pharmacokinetic and pharmacodynamic changes resulting from the interactions of the different drugs prescribed in the OCD-BD comorbidity. Expert opinion: The literature data on pharmacokinetic and pharmacodynamic changes due to interactions of drugs commonly prescribed in the treatment of the OCD-BD comorbidity are extremely limited, and the information is inferred by findings gathered in psychiatric patients suffering from other disorders. This represents a gap in psychopharmacology that should be filled by specific studies on this important topic.

Study of 45 candidate genes suggests CACNG2 may be associated with lithium response in bipolar disorder.

BACKGROUND: Bipolar disorder is a neuropsychiatric disorder that is characterized by fluctuations between manic and depressive phases. Lithium is the original and best mood stabilizing treatment for bipolar disorder. While its mechanism is not well understood, it is believed to have a strong genetic component, as several studies suggest that lithium responsiveness, in bipolar disorder, is heritable. In this study we aimed to identify genetic variants that are associated with lithium responsiveness in bipolar disorder. METHODS: Here we present two cohorts; a retrospective cohort in which patients were surveyed about their response to lithium, and a prospective cohort, in which patients were placed on a lithium monotherapy and monitored for their response to lithium. In both cohorts, patients were stratified into two categories in terms of lithium response; good responders and poor responders. 45 genes were selected based on previous associations with lithium pathways or bipolar disorder and 684 SNPs within these genes were selected to test for association with lithium response. RESULTS: While no single SNP was significant after correcting for multiple comparisons, there were several that were nominally significant (p < 0.05). Of these nominally significant SNPs, the most highly significant SNP in both the prospective and retrospective cohorts were found to be in CACNG2, or Stargazin. The second best association with lithium response was several SNPs in NRG1, a gene that has previously been associated with schizophrenia. CONCLUSIONS: Evidence for the association of lithium response with SNPs in CACNG2 is consistent with previous findings that have identified CACNG2 as associated with both bipolar disorder and lithium responsiveness.

Putative Mechanisms of Action and Clinical Use of Lithium in Children and Adolescents: A Critical Review.

BACKGROUND: Lithium is a first-line treatment for bipolar disorder in adults, but its mechanism of action is still far from clear. Furthermore, evidences of its use in pediatric populations are sparse, not only for bipolar disorders, but also for other possible indications. OBJECTIVES: To provide a synthesis of published data on the possible mechanisms of action of lithium, as well as on its use in pediatric samples, including pharmacokinetics, efficacy, and safety data. METHODS: Clinical trials in pediatric samples with at least one standardized measure of efficacy/ effectiveness were included in this review. We considered: i) randomized and open label trials, ii) combination studies iii) augmentation studies iv) case series including at least 5 patients. RESULTS: Different and non-alternative mechanisms of action can explain the clinical efficacy of lithium. Clinical studies in pediatric samples suggest that lithium is effective in managing manic symptoms/episodes of bipolar disorder, both in the acute phase and as maintenance strategy. Efficacy on depressive symptoms/phases of bipolar disorder is much less clear, while studies do not support its use in unipolar depression and severe mood dysregulation. Conversely, it may be effective on aggression in the context of conduct disorder. Other possible indications, with limited published evidence, are the acute attacks in Kleine-Levin syndrome, behavioral symptoms of X-fragile syndrome, and the management of clozapine- or chemotherapy- induced neutropenia. Generally, lithium resulted relatively safe. CONCLUSIONS: Lithium seems an effective and well-tolerated medication in pediatric bipolar disorder and aggression, while further evidences are needed for other clinical indications.

Population Pharmacokinetics and Exposure-Response of Lithium Carbonate in Patients Based on Tubular Reabsorption Mechanisms.

BACKGROUND AND OBJECTIVE: Lithium, which is used to treat bipolar disorder, has a narrow therapeutic blood concentration range and quickly reaches clinically toxic levels. We performed a population pharmacokinetic analysis with a lithium tubular reabsorption model including urinary pH and investigated the relationship between blood lithium concentration and tremor as a side effect. METHODS: Routine clinical data, including 389 serum concentrations, were collected from 214 patients orally administered an adjusted amount of lithium carbonate. Pharmacokinetics were described using a one-compartment distribution model with first-order absorption and elimination. The fractions of the MID (Li+ + LiCO3-) and ION (2Li+ + CO32-) forms were calculated using the Henderson-Hasselbalch equation, and the influences of these fractions on clearance (CL) were evaluated. The rate of tremor development was analyzed using a logit model. RESULTS: Oral apparent CL (CL/F) was explained by nonrenal CL and renal CL, and renal CL was varied by the fractions of lithium forms influenced by urinary pH. The contribution of MID to CL was slightly larger than that of ION. The rate of tremor development was estimated to be more than 30% when the trough lithium concentration was greater than 1.26 mEq L-1. CONCLUSION: Renal function and urinary pH are important indices in lithium treatment, so the serum concentration of lithium may be predicted based on the renal function and urinary pH.

Effect of renal ischemia on urinary excretion of lithium in rats.

Lithium, administered to patients with bipolar disorders, is mainly excreted in the urine, and tubular reabsorption is involved. This study characterized the renal excretion of lithium in rats subjected to renal ischemia for 60 min or 90 min. After intravenous injection of lithium chloride at 25 mg/kg, the pharmacokinetic parameters of lithium were determined. In sham-operated rats, the renal clearance of lithium was calculated to be 1.49 ml/min/kg, and its ratio to creatinine clearance (fractional excretion) was 43.4%. Renal ischemia inhibited the renal excretion of lithium, and did not affect its fractional excretion. The urinary pH of rats with renal ischemia for 90 min was significantly higher than those of the other groups, and the linear regression with the fractional excretion of lithium in rats with renal ischemia showed a moderate correlation (r = 0.650, p = 0.00193). This study demonstrated the effect of renal ischemia on the renal excretion of lithium in rats. It was suggested that not only glomerular filtration but also the reabsorption of lithium was impaired by renal ischemia.

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 therapeutic dose monitoring in human saliva.

BACKGROUND: Lithium carbonate is valuable and effective agent in the treatment and prophylaxis of mood disorders, particularly bipolar disorder (BD). Due to its narrow therapeutic range, frequent serum lithium estimation is necessary. To avoid the discomfort of frequent venipuncture, a non-invasive method for serum lithium concentration is needed. An alternative method of determining lithium level could be saliva or urine. Literature data regarding the reliability of saliva lithium levels is not conclusive. MATERIAL AND METHODS: The aim of this study is to provide an overview of possibility to replace blood serum with saliva look through research in that field. RESULTS: Some authors conclude that there is constant ratio between serum and saliva lithium level and they suggest that saliva can replace serum for estimation lithium level. Other revealed that saliva/serum lithium ratio is constant individually, so saliva/serum lithium ratio should be estimated individually. Finally there are studies excluding the possibility of replacement serum with saliva. CONCLUSIONS: There is little number of studies on saliva clinical use in lithium level monitoring. Further studies should base on current data including methods of obtaining saliva and its biochemical analysis, collecting samples in a specific time frame from the last dosage of lithium, as well as inter-subject or intra-subject measurements.

Population Pharmacokinetics of Valproic Acid in Patients with Mania: Implication for Individualized Dosing Regimens.

PURPOSE: This study characterized the population pharmacokinetic properties of valproic acid in patients with mania and determined potential factors that affect the pharmacokinetic properties of valproic acid in this population. METHODS: Routine therapeutic drug monitoring of valproic acid concentrations, demographic data, and concomitant medications from 206 hospitalized patients with mania were retrospectively collected from Somdet Chaopraya Institute of Psychiatry and Srithanya Hospital, Thailand. Nonlinear mixed-effect modeling was used for data analysis. Covariate model building was conducted using stepwise forward addition and stepwise backward elimination. The final model was evaluated using bootstrap analysis and normalized prediction distribution error. The results were compared with those previously reported in patients with epilepsy given that there is an evidence of a difference in valproic acid clearance between patients with mania and those with epilepsy. FINDINGS: Valproic acid data were adequately described by a 1-compartment model. Significant predictors for valproic acid clearance included valproic acid dose and weight. The population estimates for valproic acid CL/F and V/F were 0.464 L/h and 23.3 L, respectively. Valproic acid clearance obtained from this study did not seem to be significantly different from that of patients with epilepsy. IMPLICATIONS: A qualified population pharmacokinetic model for valproic acid in patients with mania was developed. This model could be used to optimize valproic acid therapy in patients with mania. Valproic acid clearance could be predicted from valproic acid dose and weight of patients. This predicted clearance can subsequently be used for individualization of optimum valproic acid maintenance dose.

Lithium in Paediatric Patients with Bipolar Disorder: Implications for Selection of Dosage Regimens via Population Pharmacokinetics/Pharmacodynamics.

BACKGROUND: Lithium is a well-established treatment for bipolar I disorder in adults. However, there is a paucity of information on its pharmacokinetics/pharmacodynamics in children and adolescents. We aimed to develop the first lithium dosage regimens based on population pharmacokinetics/pharmacodynamics for paediatric patients. METHODS: Lithium concentrations, Young Mania Rating Scale (YMRS) and Clinical Global Impressions-Improvement (CGI-I) scores over 24 weeks were available from 61 paediatric patients with bipolar I disorder. The population pharmacokinetics/pharmacodynamics were co-modelled. Concentrations and clinical effects following several dosage regimens were predicted by Monte Carlo simulations. RESULTS: The pharmacokinetics were well characterised by a two compartment model with linear elimination. Including the effect of total body weight (TBW) or lean body weight (LBW) on clearance and volume of distribution decreased the unexplained inter-individual variability by up to 12 %. The population mean (inter-individual variability) clearance was 1.64 L/h/53 kg LBW0.75 (19 %) and central volume of distribution 23.6 L/53 kg LBW (6.8 %). The average lithium concentration over a dosing interval required for a 50 % reduction in YMRS was 0.711 mEq/L (59 %). A maintenance dose of 25 mg/kg TBW/day lithium carbonate in two daily doses was predicted to achieve a ≥50 % reduction in YMRS in 74 % of patients, while ~8 % of patients would be expected to have trough concentrations above the nominal safety threshold of 1.4 mEq/L. Therefore, therapeutic drug monitoring will still be required even with these dosing strategies. CONCLUSIONS: When accounting for body size, the pharmacokinetic parameters in paediatric patients were within the range of estimates from adults. Pharmacokinetic/pharmacodynamic modelling supported development of practical scientifically-based dosage regimens for paediatric patients.

How long does the pharmacokinetic interaction between carbamazepine and quetiapine last after carbamazepine withdrawal?

OBJECTIVES: Carbamazepine and quetiapine are drugs that are used as mood stabilizers in the treatment of bipolar disorders. A series of studies has shown that concurrent use of carbamazepine decreases quetiapine serum level due to induction of CYP3A enzymes by carbamazepine. METHODS: In a 30-year-old bipolar patient with mania treated with quetiapine 1200 mg and carbamazepine 900 mg per day, we measured quetiapine serum level before and after carbamazepine withdrawal. RESULTS: No serum quetiapine was detected during concurrent use of carbamazepine and was lower than the therapeutic range almost 2 weeks after carbamazepine withdrawal. The patient suffered from sedation when her serum level of quetiapine was 181 ng/ml and because she was quiet we started slowly to decrease to a quetiapine dose of 600 mg. Her serum level (45 ng/ml) was again below therapeutic levels after 3 weeks of carbamazepine withdrawal. CONCLUSION: We hypothesize that induction of CYP3A lasts even after carbamazepine withdrawal. Our hypothesis was confirmed during the next treatment of mania. The patient had been off carbamazepine for 1 year and her serum level was four times higher (210 ng/ml) on 600 mg of quetiapine than 3 weeks after carbamazepine withdrawal. The influence of carbamazepine on CYP3A enzymes lasted at least 3 weeks after carbamazepine withdrawal which is in accordance with CYP3A de-induction lasting 3 weeks. This could be important information for psychiatrists to know that in some patients it is better to use a minimum washout period of 3 weeks for carbamazepine before new treatment with quetiapine.