Benefits unclear for 1st versus 2nd generation antipsychotics
Currently, 75 percent of U.S. adults who are prescribed antipsychotic medications take these second-generation drugs, which were developed largely due to concerns about side effects with their predecessors, experts noted.
First-generation antipsychotics are also called typical antipsychotics. This class of drugs includes chlorpromazine (Thorazine), haloperidol (Haldol), perphenazine (Etrafon, Trilafon) and fluphenazine (Prolixin). Second-generation drugs, known as atypical, antipsychotics include risperidone (Risperdal), aripiprazole (Abilify), olanzapine (Zyprexa), quetiapine Fumarate (Seroquel) and ziprasidone (Geodon). There is a major cost difference between the two classes of drugs: For example, a months supply of olanzapine can cost $546, while a months supply of haloperidol ranges from $18 to $27, according to Consumer Reports.
But are these newer drugs really more effective or less risky? Researchers at the U.S. Agency for Healthcare Research and Quality reviewed 114 studies involving 22 comparisons between the two classes of drugs to answer these questions. Their review appears in the Aug. 14 issue of the Annals of Internal Medicine.
The review found that the second-generation antipsychotics are not much better than the earlier incarnations at treating positive symptoms associated with schizophrenia. "Positive symptoms" is the umbrella term for symptoms of psychosis such as delusions and hallucinations. By contrast, negative symptoms reflect a decrease or loss of normal function including expression or speech.
Two second-generation drugs, olanzapine and risperidone, did seem to be more effective at treating negative symptoms when compared with the older haloperidol, the investigators said.
There was insufficient evidence to compare risk profiles between the two classes of drugs, the researchers said. Long-term risks of antipsychotics may include diabetes, major metabolic syndrome and a neurological disorder that causes involuntary, repetitive movements (tardive dyskinesia). Metabolic syndrome refers to a cluster of risk factors that increase risk for diabetes and heart disease.