Prescription drug use among children in the USA rose 5% last year, the biggest increase of any age group and nearly four times higher than the rise seen in the overall population, says new data.

More than one in four insured children and nearly 30% of 10-19-year-olds were taking at least one prescription medication to treat a chronic condition in 2009, and the biggest increases were seen in the use of antipsychotics, diabetes and asthma treatments, according to the 2010 Drug Trend Report published by pharmacy benefit manager (PBM) Medco.

“While H1N1 caused a spike in antiviral use among children last year, the far more alarming trend since the beginning of the decade is the increasing use of medications taken by children on a regular basis and in some cases, for conditions that we don’t often associate with youth, such as type 2 diabetes,” said Medco’s chief medical officer Robert Epstein. “The fact that one in three adolescents are being treated for a chronic condition points to the need for additional health education and lifestyle changes that can address the obesity issue that is likely a driving force behind such conditions as type 2 diabetes and even asthma,” he added.

Last year, the use of type 2 diabetes medications among US patients aged 19 and under grew 5.3%; this was the largest increase across all age groups and higher than the overall utilisation growth of 2.3%.

The obesity epidemic may also be responsible for a higher prevalence of hypertension and gastroesophageal reflux disease (GERD) in the young, Medco adds. During 2001-9, use of antihypertensives in children rose 17%, while the number of children on proton pump inhibitors (PPIs) - used to treat heartburn and GERD and sometimes prescribed for colic in infants - increased 147%, it notes.

The new report also shows that utilisation and costs of behavioural drug treatments for children continue to rise. In 2009, 13.2% of US prescription drug benefit dollars spent on children went to treatments for Attention Deficit Hyperactivity Disorder (ADHD), although the biggest increase in ADHD drug usage (21.2%) was among patients aged 20-34.

Drugs that are now much more widely used in children include atypical antipsychotics, traditionally used to treat schizophrenia but more recently prescribed for a variety of psychiatric disorders. Their use in children doubled during 2001-9, a trend which many experts find worrying.

“Atypical antipsychotics are extremely powerful drugs that are being used far too commonly - especially in children - given their safety issues and side effects,” says David Muzina, a specialist in mood disorders and national practice leader of the Medco Therapeutic Resource Center for Neuroscience. “We’re seeing them prescribed for a number of different conditions, including depression and anxiety for which there is not good evidence that they are an effective treatment, and yet we’re exposing children to the possibility of extreme weight gain that could lead to a host of health problems including diabetes,” he warns.

Questions of safety have however had a major impact on curbing antidepressant use in young people, the study finds; this has dropped about 23% since 2004 when the Food and Drug Administration (FDA) issued its strongest safety warnings on the risk of suicidality in children using such drugs.

Meantime, the use of respiratory drugs grew 5.0% among US children last year and has increased 42% since 2001, due largely to rising asthma rates and greater awareness of the disease and the importance of early intervention in controlling its progression.

And for antiviral drugs, usage among children soared 46% last year, by far the largest increase of all age groups and the main reason for the 9.0% rise in utilszation for the overall US population, the study adds.

Medco notes that, in 2009, the FDA expanded pediatric usage for: - two cholesterol-lowerers, Daiichi Sankyo’s Welchol (colesevalm) and AstraZeneca’s Crestor (rosuvastatin); - AstraZeneca’s Atacand (candesartan cilexetil) for hypertension; - Ortho-McNeil-Janssen’s Axert (almotriptan) for migraines; - heartburn treatment Wyeth’s Protonix (pantoprazole); and - three atypical antipsychotics, Bristol-Myers Squibb/Otsuka’s Abilify (aripriprazole), AstraZeneca’s Seroquel (quetiapine fumarate) and Eli Lilly’s Zyprexa (olanzapine).