Aripiprazole: A different kind of antipsychotic
Aripiprazole (Abilify), an antipsychotic drug approved by the FDA
in 2002, holds special interest because of the unique way it works
and the possibility that it will have a low rate of side effects. It
works neither like the older conventional antipsychotics such as haloperidol
(Haldol) and chlorpromazine (Thorazine), nor like the novel drugs — clozapine
(Clozaril), risperidone (Risperdal), and others — that are replacing
Aripiprazole prevents hallucinations and delusions by acting in the
limbic system, the part of the brain that is a center for emotions. It
also prevents the development of movement disorders — including
akathisia (compulsive pacing and fidgeting) and parkinsonism (tremors,
stiff posture, a hesitant walk, and an expressionless face) — by
acting in the extrapyramidal system.
So far, aripiprazole seems to be free of some of the side effects that
create problems for many patients taking other antipsychotic drugs. In
tests to date, it has had little effect on heart rhythms or blood sugar
regulation. And it has not caused much weight gain or raised levels of
the hormone prolactin, which can cause breast development in men and
sexual problems in men and women.
In clinical trials involving nearly 6,000 patients, the most common
side effects of the drug have been headache, anxiety, insomnia, nausea,
and constipation. It may cause some people to feel dizzy when standing
or sitting up (orthostatic hypotension). But side effects have not caused
patients taking aripiprazole to drop out of studies at a higher rate
than those taking a placebo.
In a year-long study, aripiprazole proved to be more effective than
haloperidol for negative schizophrenic symptoms — apathy, restricted
emotional range, and inability to feel pleasure. But most clinical trials
have been short-term, lasting several months at most. The long-term risks
and benefits of aripiprazole will become clearer when patients and the
people who care for them have more everyday experience with it.
June 2003 Update
Back to Previous Page