Abbotts Cylert ( Pemoline ) is a central nervous system stimulant indicated for the treatment of attention deficit hyperactivity disorder ( ADHD ).
According to Public Citizen, Cylert has caused at least 21 cases of liver failure, including 13 resulting in liver transplantation or death.
An FDA analysis by Dr. David Graham estimated a 16.8-fold increased risk of acute liver failure due to Pemoline compared to the general population, assuming no underreporting.
Cylert has been withdrawn in the United Kingdom and Canada, because of unfavourable risk-benefit profile.
In September 1997, the United Kingdom removed Pemoline from the market.
In its announcement that the drug would be banned, the Committee on Safety of Medicines ( CSM ) wrote:
The evidence for the efficacy of Pemoline in the treatment of hyperkinetic syndrome ( ADHD ) is limited and there is no good evidence from appropriate clinical trials that Pemoline is effective in patients who have failed to respond to alternative drugs.
Since there is a significant risk of serious hepatic toxicity, which may prove fatal, the CSM considered that the risks of treatment with Pemoline outweigh the benefits and the drug has therefore been withdrawn.
In September 1999, Health Canada reached a similar conclusion and removed Pemoline from the market.
Abbott said it is already planning to discontinue Cylert because of declining sales.
Attention Deficit Hyperactivity Disorder ( ADHD ) is a condition that becomes apparent in some children in the preschool and early school years.
It is hard for these children to control their behavior and/or pay attention.
It is estimated that between 3 and 5 percent of children have ADHD, or approximately 2 million children in the United States.
ADHD was first described by Dr. Heinrich Hoffman in 1845.
The principal characteristics of ADHD are: inattention, hyperactivity, and impulsivity.
According to Diagnostic and Statistical Manual of Mental Disorders ( DSM-IV-TR ), there are three patterns of behavior that indicate ADHD.
- the predominantly hyperactive-impulsive type, that does not show significant inattention;
- the predominantly inattentive type , that does not show significant hyperactive-impulsive behavior;
- the combined type , that displays both inattentive and hyperactive-impulsive symptoms.
For decades, medications have been used to treat the symptoms of ADHD.
The medications that seem to be the most effective are a class of drugs known as stimulants , including Amphetamine, Methylphenidate.
Most side effects of the stimulant medications are minor and are usually related to the dosage of the medication being taken.
Higher doses produce more side effects.
The most common side effects are: decreased appetite, insomnia, increased anxiety, and/or irritability.
Some children report mild stomach aches or headaches.
1) ABC News
2) Public Citizen
3) National Institute of Mental Health / NIH