Attention deficit hyperactivity disorder - lisdexamfetamine
Attention deficit hyperactivity disorder, or ADHD, is a neurological developmental disorder.
Attention deficit hyperactivity disorder, or ADHD, is a neurological developmental disorder.
It first appears in childhood, and symptoms include forgetfulness, hyperactivity and being easily distracted. Both genetic and environmental factors are implicated.
Two classes of drugs are available: psychostimulants such as amphetamines and methylphenidate, and atomoxetine, a non-stimulant antidepressant. About 90% of patients respond to psychostimulants, but there is a distinct possibility that misuse can lead to addiction, and because a dose needs to be given in the middle of the day, it would be preferable for schoolchildren if an agent that did not need a mid-day dose were available. As a result, New River is developing lisdexamfetamine mesilate along with Shire; it has a longer duration of action with efficacy lasting all day.
A total of 52 children with ADHD aged between six and 12 were given the drug in a simulated classroom situation during a multicentre, randomised, double blind, placebo-controlled crossover Phase II trial.1 Subjects were given 30, 50 or 70mg of the drug a day, placebo, or extended release mixed amphetamine salts (Adderall XR). A one-week screening phase was first carried out, followed by a three-week dose optimisation phase with Adderall XR, and then the three-week trial phase. Both drugs were better at controlling symptoms than placebo, and there was no significant difference between the effects of the two drugs.
A four-week multicentre, randomised, double blind, placebo-controlled parallel group Phase III study has also been carried out.2 A total of 290 children between the ages of six and 12 were studied; a week-long screening period was followed by another week of washout, and then a four-week double blind phase, with subjects given 30, 50 or 70mg of lisdexamfetamine or placebo. All doses of the drug gave significant improvements in ADHD symptoms. Phase III trials are under way in adults, looking at the effects of single morning doses of the drug, and it has recently been approved for use in children by the FDA under the brand name Vyvanse.