Friday, October 17, 2008

Risperidone Boosts ADHD Stimulant Medication Effects

ADHD Medications

We often search the fine print for ADHD medication labels to see if there are potentially negative drug-drug interactions. However, an equally valid question may be: are there other medications which may boost or augment the effectiveness of an ADHD medication while keeping negative side effects to a minimum? The answer to this question appears to be "yes". We have seen in a previous post how ADHD medications and treatments can often overlap those of co-occurring disorders, such as in bedwetting. We have also seen how Atomoxetine (Strattera) can be an effective treatment option for ADHD and Tourette's. We have also explored the relative safety of ADHD stimulant medications taken during pregnancy. Now we will discuss is which medication strategies are effective for ADHD and comorbid conduct disorders and evaluate the relative safety of these medication combos.

The drug Risperidone (also referred to as Risperdal or Rispen), is a relatively new antipsychotic medication which was released in 1993 for adults and was approved in 2007 as a treatment option for both pediatric schizophrenia and pediatric bipolar disorders. A year prior to this, it was used as a potential treatment medication for pediatric autism. Given the fact that individuals with ADHD are more prone to exhibiting multiple symptoms of these disorders, Risperidone is a potential agent of interest for certain forms of ADHD.

A key study was done in 2004 by MG Aman and colleagues and was published in the Journal of Child and Adolescent Psychopharmacology, which focused on the effects of Risperidone when used in conjunction with other stimulant medications for treating ADHD in children of sub-average IQ's during a 6-week study period. Additionally, differences in behavioral disorders frequently seen alongside ADHD, such as Conduct Disorder (CD) and Oppositional Defiant Disorder (ODD) were also monitored by the study.

Although not a stimulant medication itself, the study's findings suggest that Risperidone may prove to be useful in augmenting these stimulant medications' effectiveness for these disorders or combinations of disorders. Additionally, results from the study suggest that Risperidone,by itself is often an effective treatment for hyperactivity and conduct disorders that often occur alongside ADHD. When combined with stimulants, the overall effectiveness is even greater.

Safety-wise, the study found that the use of Risperidone produced no noticeable change in the number of stimulant-related adverse drug effects. The three main ADHD stimulant medications used in the study were Methylphenidate, Pemoline, and Dextroamphetamine, with levels for each medication covering a wide dosage range. It is first important to note that while methylphenidate and dextroamphetamine are both considered to be relatively safe stimulant medications for treating ADHD, Pemoline (Cyclert) is known to be potentially harmful to the liver, and is typically used sparingly, often as a last resort among many physicians. What the study observed, however, is that risperidone, when taken alongside these stimulant medications, does not increase the number or severity of these side effects (Risperidone treatment did result in slightly more weight gain than the placebo controls, but the overall difference was small). This should be taken as good news for those concerned with the overall safety and effectiveness of combining stimulant and non-stimulant medications.

While ADHD stimulant medications and antipsychotic agents have different modes of action and different biological "targets", the results of this study suggest that the two types of medication are often able to work together and improve each other's effectiveness, while incurring minimal side effects. This suggests that for children with both ADHD and some type of oppositional or conduct disorder, prescribing Risperidone along with a stimulant medication such as Ritalin, Concerta or Dexedrine may be a highly effective and relatively safe treatment option.

ADHD medications