Saliva lithium monitoring in prepubertal children

Relationship between serum lithium, salivary lithium, and urinary lithium in patients on lithium therapy

Lithium carbonate is used in the treatment of both psychiatric and nonpsychiatric disorders. The aim of this study was to explore the relationship between serum lithium, salivary lithium, and urinary lithium. Blood, saliva, and urine samples were collected from 50 patients, and estimation of serum, salivary, and urine lithium was done using an atomic absorption spectrophotometer. Mean serum lithium was 0.75 ± 0.25 mEq/L, mean salivary lithium was 1.91 ± 0.80 mEq/L, and mean urine lithium was 7.16 ± 4.84 mEq/L. A significant direct correlation was found between serum lithium and salivary lithium (r = 0.695, p < 0.001). This correlation was higher in females (r = 0.770, p < 0.001) when compared to males (r = 0.665, p < 0.001). Even though a significant correlation was found between serum and salivary lithium levels, more studies are needed in this domain to establish salivary therapeutic monitoring as a feasible option for patients on lithium carbonate therapy.

The use of oral fluid for therapeutic drug management: clinical and forensic toxicology

One of the underlying tenets of clinical pharmacology is that only free drugs are pharmacologically active. It is thought that only free drugs can cross biological membranes to interact with a given receptor to alter its function, and that drug responses, both efficacious and toxic, are a function of unbound concentrations. The rationale for measuring drugs in oral fluid is that the free fraction of a drug in plasma reaches equilibrium with the drug in saliva. Although reports concerning the appearance of organic solutes in saliva have been in the literature for over 70 years, it has only been in the past 30 years that there has been emphasis on the appearance of drugs. Although many assumptions for drug level monitoring in saliva are made, the primary requisite for salivary monitoring to be useful is a constant or predictable relationship between the drug concentration in saliva and the drug concentration in plasma. Measurement of oral fluid drug levels for the purpose of managing patients and making dosage adjustments may be useful for select drugs or drug classes. However, it does not appear to be useful for the majority of drugs therapeutically monitored. Some work with antipsychotic medications has indicated that although the measurement of drug concentrations themselves may not be useful for dosage adjustment, the ratio of parent drug to metabolite may reflect altered metabolic status due to either pharmacogenetic variation or other clinical conditions. Furthermore, analysis of saliva may provide a cost-effective approach for the screening of large populations.

Mood stabilizers in children and adolescents

OBJECTIVE

The efficacy of mood stabilizers in children and adolescents has not been studied adequately. This article will review existing studies and highlight some important issues in designing future studies on these agents.

METHOD

Electronic databases including Medline, Psycholnfo, and CRISP were searched for data in children receiving compounds that have mood-stabilizing properties in adults.

RESULTS

Some open clinical data and an extremely modest amount of controlled research data suggest lithium, carbamazepine, and valproate may be effective mood stabilizers in children and adolescents. There are no controlled data on other potential mood stabilizers in children.

CONCLUSIONS

The disorders that may be responsive to mood stabilizers are among the most morbid in child psychiatry. More studies are needed to clarify the efficacy of these compounds in children and adolescents and to provide a rational basis for choosing among them.

Biologic variation of serum and salivary lithium

Within- and between-subject variability in serum and salivary lithium concentrations in nine psychiatric inpatients on stable drug regimens undergoing therapy has been assessed using criteria for determining biologic variation. This allows separation of analytic from other measures of variance. There were marked differences in inter- and intra-subject variance for serum and salivary lithium concentrations for serum/salivary ratios. Moreover, these variances were greater for salivary lithium than for serum concentrations. The results have been used to assess analytical performance, the usefulness of the therapeutic range, and the reference change interval. Despite greater variance for salivary concentrations, predicted serum concentrations from predetermined serum/saliva ratios were in good agreement with actual concentrations in most subjects.

Bipolar disorder in children: misdiagnosis, underdiagnosis, and future directions

Bipolar disorder has not been well studied in prepubertal children, despite its potentially debilitating effects on growth and development. However, there have been case reports of mania in this age group dating back to Esquirol in the mid-19th century. Despite anecdotal case reports, explicit criteria to diagnose mania in children were not used until 1960. Since 1980 the DSM-III/DSM-III-R criteria have indicated adult criteria can be used to diagnose childhood mania, with some modifications to adjust for age differences. Bipolar disorder has not been frequently considered in the psychiatric differential diagnosis of children. However, if a diagnosis of mania is made, clinical rating scales can be used to rate the severity of manic symptoms and to monitor treatment. A manic child should be treated using a biopsychosocial approach. To date, lithium carbonate has been the most commonly used psychopharmacological treatment, but results have been variable. Additional research is needed, including double-blind, placebo-controlled studies to document the beneficial effects of mood-stabilizing medications. Also, diagnostic instruments should be refined to improve their utility. Finally, children at high risk for developing mania should be studied to identify predictors of bipolar disorder in children.

Update on lithium carbonate therapy in children and adolescents

The use of lithium to treat child and adolescent psychiatric disorders is becoming more common. Since the publication of the report of The Committee on Biological Aspects of Child Psychiatry of the American Academy of Child Psychiatry in 1978, a considerable body of literature has accumulated on the efficacy of lithium in treating adolescent bipolar disorders, childhood aggression, and behavioral disorders associated with mental retardation and developmental disorders. Efforts to understand lithium's mechanism(s) and refinements in psychiatric diagnosis have contributed to its growing use.

Early findings from a pharmacokinetically designed double-blind and placebo-controlled study of lithium for adolescents comorbid with bipolar and substance dependency disorders

1. This manuscript reports the early findings from a National Institute on Drug Abuse funded study of lithium for adolescents dually diagnosed with bipolar and substance dependency disorders. The authors elected to publish early findings in the hope that it would accomplish a twofold mission. 2. The first part would be to encourage other investigators to participate in research in this area and the second would be to heighten the awareness of clinicians that adolescents presenting with either one of these disorders might also have the other. 3. The early findings demonstrated the feasibility of recruiting, retaining and monitoring this complex population on an outpatient basis. 4. Steady-state serum lithium levels were pharmacokinetically placed in the study range, 0.9-1.3 mEq/L. Preliminary results are encouraging in finding lithium more effective than placebo for alleviating both the substance dependency and the mood disordered symptomatology. 5. The characteristics of the study population to date have been chronicity of both disorders, impairment in the severe range in multiple areas of functioning, and strong family histories for both affective and substance use disorders. The substance dependency was to both alcohol and marijuana; but all subjects also had marked polydrug abuse. 6. In order to best monitor lithium compliance and drug/alcohol use during protocol, randomly timed weekly serum and urine assays were obtained. 7. The implications of these early findings for the outcome of this acute phase study and for the development of longitudinal treatment strategies are discussed.