Pharmacological Treatment Options for Autism, Part 2. (EP on Autism)

Article excerpt

Overview of Medications

In the first part of this series, we focused on using neuroleptics to treat autism spectrum disorders. In this part, we will examine three other major groups of medications: anti-depressant/ anti-anxiety agents, stimulants and anticonvulsants.

Anti-Depressant and Anti-Anxiety Agents

Serotonin re-uptake inhibitors, such as fluoxetine (Prozac), sertraline (Zoloft), paroxetine (Paxil), fluvoxamine (LUVOX), and clomipramine (Anafranil) have been of great interest in autism over the past 10 years because of their effectiveness in treating obsessive-compulsive symptomatology. Repetitive, ritualized, seemingly "compulsive" behavior has been recognized as a major part of autism since its earliest description by Leo Kanner in the 1940s.

Modern diagnostic criteria for autism includes repetitive and stereotyped body movements such as arm-flapping, spinning, and running back and forth (motor stereotypes). Simple rituals such as lining up objects, opening and closing doors, insisting on objects being in a particular place or daily procedures being carried out in a specific way, also form part of modern diagnostic criteria. In addition, more classic "obsessive-compulsive" rituals such as hoarding, washing, counting and touching rituals are frequently seen in autism. These repetitive behavior patterns can be associated with severe anxiety, tantrums and aggressive behavior toward self and others. They may also be highly time-consuming and disruptive to learning.

This group of medications also held interest for autism researchers because of the consistent finding of elevated levels of serotonin in the bloodstream in approximately one-third of individuals with autism. Although this group of medications exerts effects on multiple neurotransmitter systems, these agents are potent blockers of serotonin re-uptake into cells and could potentially reverse some of the serotonin dysregulation in autism.

The three serotonin re-uptake blockers that have been primarily studied in autism are clomipramine (Anafranil), fluvoxamine (LUVOX), and fluoxetine (Prozac). Studies report these agents can reduce the frequency and intensity of repetitive, ritualized behaviors including motor stereotypies and more classic compulsions. In addition, improvements in other autistic symptoms have also been noted. For instance, some children show improvements in eye contact, social initiation and responsiveness. Others show decreased withdrawal and expanded repertoire of interests. Decreased irritability, tantrums and aggression toward self and others have been noted. Improvements in initiating, shifting and sustaining attention are also observed, with improvements in "connectedness" to the environment and therefore less internal preoccupation. Many of these associated benefits may relate to the potent anti-anxiety effects of these medications, although there may also be a direct "alerting" effect related to improvements in certain aspects of joint attention.

These three medications differ in their side effect profiles, with clomipramine (Anafranil) having a greater frequency and severity of adverse effects compared to fluoxetine (Prozac) and fluvoxamine (LUVOX). The most common side effects of all three agents are hyperactive, impulsive behavior and sleep disturbance. Both of these side effects are dose-related and can be minimized with careful and conservative dose titration. Clomipramine (Anafranil) may also cause dry mouth, dizziness and constipation (so-called anti-cholinergic side effects) as well as heart rhythm changes (baseline EKG monitoring is necessary) and a lowering of the seizure threshold (making it a more problematic medication in individuals with seizures). However, in healthy patients without seizures and with normal heart functioning, clomipramine is generally safe and well-tolerated. Each of these three medications have been studied in children and have been found to be safe, with side effect frequency and severity being similar to that seen in adults. …