Lithium therapy

An investigation into lithium monitoring

The quality of lithium monitoring in a health district serving a population of 450 000 was studied over a period of a year. The following instances of poor monitoring were found: too frequent monitoring in stabilised patients, and failure to take action when lithium values fell below 0.3 mmol/l or rose above 1.0 mmol/l. Ways of improving the standard of monitoring are considered.

Old drug, new data

New data have emerged over the past 10 years regarding the efficacy and mechanisms of action of lithium. This article briefly summarises the evidence for the use of lithium to treat affective disorders and psychosis, reviews its putative anti-suicidal effect, highlights new research on its mechanism of action and provides an update on some important side-effects and consequences of its use.

Thyroid functions and bipolar affective disorder

Accumulating evidence suggests that hypothalamo-pituitary-thyroid (HPT) axis dysfunction is relevant to the pathophysiology and clinical course of bipolar affective disorder. Hypothyroidism, either overt or more commonly subclinical, appears to the commonest abnormality found in bipolar disorder. The prevalence of thyroid dysfunction is also likely to be greater among patients with rapid cycling and other refractory forms of the disorder. Lithium-treatment has potent antithyroid effects and can induce hypothyroidism or exacerbate a preexisting hypothyroid state. Even minor perturbations of the HPT axis may affect the outcome of bipolar disorder, necessitating careful monitoring of thyroid functions of patients on treatment. Supplementation with high dose thyroxine can be considered in some patients with treatment-refractory bipolar disorder. Neurotransmitter, neuroimaging, and genetic studies have begun to provide clues, which could lead to an improved understanding of the thyroid-bipolar disorder connection, and more optimal ways of managing this potentially disabling condition.

Bipolar affective disorder: advances in genetics and mood-stabilising medication

The lifetime prevalence of bipolar affective disorder is between 1 % and 2%. This educational review paper focuses on two areas of interest and relevance to trainees preparing for the membership examination of the Royal College of Psychiatrists: (a) advances in the genetics of bipolar affective disorder; and (b) mood-stabilising medication in bipolar affective disorder.

Developments in mood stabilisers

Bipolar affective disorder is a life-long condition with profound effects on sufferers' social and occupational life. Despite efficacy in clinical trials and in some groups of patients, lithium's effectiveness in clinical practice is hampered by its side effect profile and limited concordance. Alternative and adjunctive treatments to lithium in bipolar disorder have been sought and the anticonvulsants carbamazepine and valproate show promise. Despite these advances, treatment resistance persists. Lamotrigine, a new anticonvulsant, is increasingly used in treatment-resistant cases under specialist supervision. Further pharmacological and non-pharmacological strategies for bipolar prophylaxis are currently under investigation. These developments are the focus of this review.

Lithium-associated clinical hypothyroidism. Prevalence and risk factors

BACKGROUND

Rates of, and risk factors for, lithium-associated clinical hypothyroidism are uncertain.

AIMS

To determine prevalence of and risk factors for clinical hypothyroidism in patients treated with lithium carbonate.

METHOD

Retrospective case-note review of 718 patients who had undergone serum lithium estimation during a 15-month period. Patients on thyroxine had a more detailed review.

RESULTS

The prevalence of clinical hypothyroidism during lithium treatment was 10.4%. The main risk factor was female gender (women 14% v. men 4.5%). Women were at highest risk during the first two years of lithium treatment, and women starting lithium aged 40-59 years had the greatest prevalence (> 20%). No equivalent risk factors emerged in men, although, like women, their prevalence of hypothyroidism was substantially higher than community rates.

CONCLUSIONS

The high rates of clinical hypothyroidism identified may call for a review of the drug information given to women, particularly to those starting lithium in middle age. Consideration should be given to screening for thyroid antibodies before treatment in high-risk cases. Monitoring of thyroid function should take into account gender, age and stage of lithium treatment.