An injectable antipsychotic medication whose effects last for three months has successfully delayed the return of schizophrenia symptoms, researchers have found. Taking the drug in this form may help people with schizophrenia who struggle to stay on treatment by enabling them to take medication less frequently.                                                                                                    

The research team, which included Adam J. Savitz, M.D., Ph.D., recipient of a NARSAD Young Investigator Grant in 2001, examined use of the long-acting antipsychotic medication paliperidone palmitate (Invega) in treating symptoms of schizophrenia such as hallucinations, delusions, and strong feelings of suspicion. The research was published online March 29th in JAMA Psychiatry.

When a person with schizophrenia cannot maintain a daily medication schedule, the drug level in his or her body can dip too low to combat symptoms, leading to relapse (return of symptoms) and an increased risk of being hospitalized. This study aimed to determine whether a dosage that would only have to be taken once every three months, rather than every day, would effectively hold off symptoms. After starting with a once-monthly dosage, patients took a three-month dosage to maintain symptom prevention and then were given randomly either placebo or the same three-month dosage every 12 weeks to see whether the medication’s positive effects would persist. (A placebo is a look-alike with inactive ingredients.)

Significantly fewer people who got the second three-month dosage experienced symptom relapse during the experimental phase of the study, compared to those taking a placebo. During this phase, the placebo group also reported more severe symptoms, while the paliperidone palmitate group’s symptoms remained constant.

The two groups also showed different patterns of side effects. The more serious side effects occurred in the placebo group: anxiety and return of other symptoms of schizophrenia. The paliperidone palmitate group more frequently experienced headaches, weight gain, common colds, as well as so-called extrapyramidal symptoms, which involve disruptions to movement.

This study did not include people with a history of substance dependence, major active medical problems, or other serious mental disorders. More research is needed to know whether less frequent dosage of long-acting injectable medication like paliperidone palmitate can help prevent relapse in these groups.



Read the abstract.