Tarnow Articles

Keeping Pace with Changes in Antipsychotic Treatment 

In the world of psychiatry, the class of medications named "antipsychotics" is used to treat a variety of target symptoms. Antipsychotics are crucial in treating schizophrenia, which is defined by the presence of psychotic symptoms. Such symptoms include auditory and visual hallucinations and paranoia, as well as disorganized and/or aggressive behaviors. The antipsychotics are also helpful in treating the acute episodes of Bipolar Disorder and Major Depressive Disorder. In child psychiatry, antipsychotics such as Risperdal have long been used in disorders such as Tourette's Syndrome to decrease tics, Autistic Disorder, and Behavior Disorders to decrease impulsive aggression.

Over the years, the medications classified as antipsychotics have become safer with fewer side effects. This past November, a new atypical antipsychotic, Abilify, was given conditional approval by the FDA. It is now available in the United States. As mentioned above, this could be an exciting new treatment option for a number of different psychiatric illnesses.

Abilify (or aripiprazole) has been touted as a "unique" antipsychotic in that its manufacturer believes it could help to regulate dopamine through either increasing or decreasing D2 receptor activity when needed. In theory, this would treat the symptoms of schizophrenia more effectively. When in an acute psychotic state, the D2 receptor activity would be decreased. If little or no dopamine is present, Abilify reportedly increases D2 receptor activity. This latter effect would work to decrease the debilitating "negative" symptoms of schizophrenia, such as amotivation, ambivalence, social withdrawal, and lack of affect or expression.

Abilify has been said to effectively treat both the positive and negative effects of schizophrenia with an excellent side effect profile.

Currently, side effects such as sedation and weight gain remain a barrier to medication compliance. The sedation and weight gain are caused by activation of histamine receptors. Abilify is said to have a low affinity for the histamine receptors. Medications that affect the muscarinic cholinergic receptors can potentially cause cognitive impairment. Abilify is also said to have low affinity for the cholinergic receptors so that cognitive difficulties should not be present. Abilify also has low affinity for the oc adrenergic receptor, which would decrease potential for the side effect orthostatic hypotension, which caused much cardiovascular trouble in the past, particularly for the elderly.

Trials performed demonstrated that doses 15 and 30 mg/day were superior to placebo and as effective as Haldol (10 mg/day) and Risperdal (6 mg/day) in decreasing psychotic symptoms. At the same time, no increase in prolactin or the cardiac QTc interval was found. Extrapyramidal symptoms such as dystonias and tardive dyskinesia are comparable to placebo. Weight gain was only modest. Headache, anxiety, insomnia, and nausea were listed as the most common adverse effects.

Abilify is prescribed in 10-, 15-, 20-, and 30- mg. tablets. Recommended starting dose is 15 mg. daily. Contrary to premarketing trials, daily doses of 20 and 30 mg. do appear more efficatious than starting at 15 mg/day. The manufacturer advises not increasing dosage until steady state has been achieved at two weeks of treatment.

Although Abilify is quite young in its career as an antipsychotic, it could potentially treat both the positive and negative symptoms of schizophrenia with a manageable side effect profile. If the side effects continue to remain this benign, Abilify will no doubt be helpful in managing other disorders where antipsychotic treatment has been helpful. As with all new medications, unexpected benefits and complications may be exposed after release to the public. For this reason, the risks of treatment vs. non-treatment or alternative treatment should be discussed. In many schizophrenic patients, the side effects of alternative medications and the safety risks of non-treatment will combine to make Abilify an attractive option.