As drugmakers seek wider approval for their antipsychotics to be prescribed for youngsters, a new study finds some docs prescribed Risperdal for children 15 years old or younger who suffered insomnia or anxiety. Meanwhile, the med caused some kids to experience drowsiness, depression, tooth decay and weight gain. The findings were part of a national study in New Zealand and published in the latest edition of Drug Safety.

More than 90 per cent of prescriptions for the 420 children involved in the study were for Risperdal, which is called Ridal in New Zealand, where about 600 children are regularly prescribed the drug. The study by the Intensive Medicines Monitoring Programme found harmful side effects in 30 per cent of the children on the drugs classed as “atypical antipsychotics.” A third of these were linked to the drugs, say the researchers.

Co-author Mira Harrison-Woolrych says this was the first study in the world to paint a comprehensive, real-life picture of how the increasingly-prescribed second-generation antipsychotics are being used in children. “Weight gain, tooth decay and sleepiness were the most common adverse events we found,” Harrison-Woolrych, who directs the monitoring programme based at Otago University, tells The New Zealand Herald.

The finding of higher levels of tooth decay was unexpected, as were symptoms of depression in four children - a previously unidentified adverse reaction.

“The children that developed the symptoms of depression didn’t have depression to start with … We were very cautious and only coded those events where the psychiatrist or the doctor had definitely said the child had developed symptoms of depression,” she says, adding that seven other children had symptoms that suggested depression.

Harrison-Woolrych says there were other factors involved with these kids. “We’re not saying that we’ve definitely shown that risperidone causes depression in children, what we’re saying was this was an unexpected finding. We think it needs further work and we think that clinicians, doctors and carers of children should just be aware that this is a potential finding.”

As well as gathering data on adverse reactions, the researchers also investigated the children’s diagnoses and the symptoms being targeted by the drugs. They found conduct disorders and attention deficit and hyperactivity disorder to be among the most common diagnoses, followed by autism, Asperger’s syndrome and other developmental disorders.

Child psychiatrist and co-author Juan Garcia-Quiroga says aggression and difficult behaviours were found to be the most common target symptoms. The use of the drug in these instances was appropriate.

But the study also found doctors prescribing the drug for anxiety and personal developmental disorders as well as sleeping disorders - conditions which were outside the terms of the product licence at the time of the study.

Dr David Menkes, associate professor of psychiatry at Auckland University’s Waikato clinical school, said some of the cases where the drug was prescribed was “worrisome”…”Every case has to be judged on its merits, but to be using a powerful antipsychotic drug for insomnia, for example, I think it likely to be questionable.”

The UK’s health medicines regulatory body had already shown interest in the findings, says Dr Harrison-Woolrych. “While prescriptions of these medicines in children and adolescents have increased vastly worldwide, there has been a lack of good evidence about their long-term safety.”