Fluoxetine in Tourette's syndrome

New therapeutic approach to Tourette Syndrome in children based on a randomized placebo-controlled double-blind phase IV study of the effectiveness and safety of magnesium and vitamin B6

Background

Tourette Syndrome (TS) is a neurological condition presenting chronic motor and phonic tics, and important degree of comorbidity. Considered an uncommon illness, it first becomes apparent during childhood. Current standard treatment only achieves partial control of the condition, and provokes frequent, and sometimes severe, side effects.

Methods and design

Main aim:

To show that, with respect to placebo treatment, the combination of 0.5 mEq/Kg magnesium and 2 mg/Kg vitamin B₆ reduces motor and phonic tics and incapacity in cases of exacerbated TS among children aged 7–14 years, as measured on the Yale Global Tic Severity Scale (YGTSS).

Secondary aims:

Assess the safety of the treatment.

Describe metabolic changes revealed by PET.

Measure the impact of the experimental treatment on family life.

Methodology

Randomized, blinded clinical trials. Phase IV study (new proposal for treatment with magnesium and vitamin B₆). Scope: children in the geographic area of the study group. Recruitment of subjects: to include patients diagnosed with TS, in accordance with DSM-IV criteria (307.23), during a period of exacerbation, and provided none of the exclusion criteria are met. Instrumentation: clinical data and the YGTSS score will be obtained at the outset of a period of exacerbation (t0). The examinations will be made after 15 (t1), 30 (t2), 60 (t3) and 90 days (t4). PET will be performed at the t0 and t4. We evaluated decrease in the overall score (t0, t1, t2, t3, t4), PET variations, and impact made by the treatment on the patient's life (Psychological General Well-Being Index).

Discussion

Few clinical trials have been carried out on children with TS, but they are necessary, as current treatment possibilities are insufficient and often provoke side effects. The difficulty of dealing with an uncommon illness makes designing such a study all the more complicated. The present study seeks to overcome possible methodological problems by implementing a prior, phase II study, in order to calculate the relevant statistical parameters and to determine the safety of the proposed treatment. Providing a collateral treatment with magnesium and vitamin B₆ could improve control of the illness and help reduce side effects.

This protocol was approved by the Andalusian Government Committee for Clinical Trials (Spain).

This study was funded by the Health Department of the Andalusian Regional Government and by the Healthcare Research Fund of the Carlos III Healthcare Institute (Spanish Ministry of Health).

Trial Registration

Current Controlled Trials ISRCTN41082378

Pharmacology of the selective serotonin reuptake inhibitors in children and adolescents

OBJECTIVE

To review the pharmacology of a new class of medications, the potent selective serotonin reuptake inhibitors (SSRIs), what is known about their metabolism in children and adolescents, and the practical clinical implications of such.

METHOD

Articles were retrieved through index Medicus searches for articles published during the past 10 years on the SSRIs and on pediatric pharmacology.

RESULTS

More than 300 articles were reviewed. Pharmacological data, derived from relevant adult literature, were summarized and extrapolated to children and from the limited pediatric literature. The SSRIs represent a new class of antidepressants with distinct advantages in their side effect profile and their broad therapeutic index over that seen with the tricyclic antidepressants. Their advantage of few anticholinergic side effects and limited cardiovascular toxicities are particularly relevant for the pediatric population. The SSRIs are metabolized via the hepatic cytochrome isoenzyme P450 system, and potential drug-drug interactions are reviewed.

CONCLUSIONS

The SSRIs appear to offer advantages over the tricyclic antidepressants. Unfortunately, pharmacokinetic data are lacking, and systematic studies of safety and efficacy in the pediatric age group are limited. Preliminary reports are encouraging, but further study is required.

Tourette syndrome. Secondary tic disorders

The putative relationship between a variety of neurologic and neuropsychiatric disorders, which have been reported in association with tics, is reviewed. Tics also may be increased or exacerbated by drugs affecting a variety of neurotransmitter systems. Recognition and study of these secondary tic disorders may further our understanding of basal ganglia physiology and the pathogenesis of Tourette syndrome.