UKPPG Bulletin archives Learning Disabilities study day

2nd THERAPEUTICS IN LEARNING DISABILITIES (1997)

The third annual conference on therapeutics in learning disabilities was held in Leicester on 7th November 1997. Approximately 80 people, including about 20 pharmacists, attended this multidisciplinary meeting which was jointly run by the UKPPG and the specialists in learning disabilities from Leicester and Nottingham.

Dr D Clarke, Senior lecturer from the University of Birmingham, Department of Psychiatry discussed the role of drug treatments in the management of severely self-injurious behaviour (SSIB) associated with mental retardation. Historically, such behaviours have often been treated with antipsychotic medication. The efficacy of antipsychotics in the treatment of SSIB has not been established, although there is evidence in favour of some compounds in the treatment of SSIB of a stereotyped nature. Recent research suggests that dopamine D1 pathways, serotonergic systems and neuropeptide systems are implicated in the maintenance of SSIB. More rational treatment approaches may result from these insights. Clinical trials are difficult to conduct, because both SSIB and severe mental retardation are relatively rare conditions. Additionally, cognitive and communication problems result in ethical problems for researchers, and study samples are often heterogeneous with regard to aetiology, which may influence treatment response.

Evidence for efficacy seems to be greatest for naltrexone. Clomipramine was found to be beneficial in a recent controlled study. Fluoxetine and lithium may benefit some people. Of the antipsychotics, there is some evidence to support the use of thioridazine where SSIB is associated with stereotyped behaviour. Fluphenazine and clozapine may be effective, but their usefulness may be limited by adverse effects or the need for repeated venesection. The development of dopamine D1 antagonists with fewer adverse effects than existing antipsychotics may bring benefits. Further studies are needed, and the interplay between biological and psychological mechanisms influencing SSIB merits particular attention.

Dr Sabyasachi Bhaumik, Consultant in Psychiatry of Learning Disability, Leicester Frith Hospital addressed the subject of SSRI antidepressants in learning disabilities. He stated that very few studies have been undertaken to look at the use of antidepressants in adults with learning disabilities and, more recently, with the advent of SSRIs there has not been a study comparing the use of fluoxetine and paroxetine in this population. A naturalistic study involving adults with learning disabilities suffering from depressive illness was undertaken in Leicestershire that included 147 treatment episodes with fluoxetine or paroxetine and issues related to efficacy, tolerability, side-effects, polypharmacy and discontinuation rates were looked at. The study, despite its limitations, establishes that depressive illness in patients with learning disabilities does respond to SSRI treatment in the same way as that of the general population. The findings suggest that the clinical efficacy of both fluoxetine and paroxetine is similar and there is no significant difference between these drugs in the areas of side effects and discontinuation rates. The study also highlights the fact that both these drugs are safe to use in conjunction with other drugs, including neuroleptics, lithium and anti-epileptics.

Dr Sarah Bernard, Consultant Psychiatrist for children with learning disabilities, The Maudsley Hospital, discussed the value of methylphenidate to control hyperactivity in people with learning disabilities. Children with learning disabilities are believed to have a higher incidence of hyperactivity when compared to those without disabilities. Medication, in combination with behavioural treatments, has been demonstrated as being of benefit, although research is sparse in this field. She addressed the complexities of making a diagnosis of hyperactivity in children with learning disabilities and then discussed the role of methylphenidate for this group.

Dr D Branford, Consultant Pharmacist, Glenfrith Division of Fosse Health NHS Trust, Leicester presented some recent work on the use of risperidone in learning disabilities. He stated that the success of clozapine and the scientific advances in the techniques available to study brain structures and chemistry have led to the development of many new antipsychotic drugs. The proposed benefits of the new drugs for the treatment of schizophrenia are increased efficacy and reduced side effects. Up to 40% of antipsychotic drug prescriptions are for indications outside schizophrenia; the control of maladaptive behaviours both in the demented elderly and in people with learning disabilities probably being the largest. In the field of learning disabilities up to 25% routinely receive antipsychotic drugs for a variety of maladaptive behaviours including aggression, self-injury and stereotypes. Results from a small case note audit suggest that the new atypical antipsychotic drugs may provide additional benefits in the control of such behaviours.

During the afternoon a number of case studies were presented for discussion of the most appropriate treatments. These workshops involved both a panel of experts and delegates providing opinions about cases involving epilepsy, challenging behaviours and hyperactivity.

The final session involved a number of short presentations. They included;

A comparative study of the administration of depot injections by community nurses, learning disabilities and psychiatric Nurses
A Study to eradicate drug administration in day centres
A presentation of the controversy over the appropriate dose of rectal diazepam
Two cases involving the use of clozapine.

The conference proved to be extremely popular with the attendees. It is anticipated that there will another conference on therapeutics in learning disabilities but it may be delayed to the spring of 1999 to avoid the huge number of conferences that take place in the autumn.

Report by Dr. Dave Branford, who at the time was Consultant Pharmacist, Leicester Frith Hospital, Groby Road, Leicester LE3 9QF