NEW YORK (Reuters Health) Jan 27 – Among recent-onset schizophrenia patients prescribed risperidone, nonadherence rapidly leads to the return of positive symptoms, researchers report in a January 4th online paper in the American Journal of Psychiatry.
“Something that was quite striking in this study was that even brief periods of partial nonadherence lead to greater risk of relapse than what is commonly assumed,” Dr. Kenneth L. Subotnik, told Reuters Health by email.
“Schizophrenia patients often lack insight into the continued need for antipsychotic medication and either covertly or overtly stop taking some or all of their medication. This is a common clinical situation in outpatient treatment,” he pointed out.
Dr. Subotnik of the University of California, Los Angeles and colleagues studied 49 patients. The degree of antipsychotic medication adherence was rated weekly for up to 18 months following initial outpatient stabilization on risperidone.
Nondetectable levels of 9-hydroxyrisperidone were used to flag nonadherence.
Overall, 32% were considered adherent; 33% had a period of mild nonadherence. Moderate (16%) and severe (19%) nonadherence were relatively less common.
During follow-up, 13 patients had a return of psychotic symptoms meeting exacerbation or relapse criteria.
Compliance with only 50% to 75% of the prescribed medication for 2 or more consecutive weeks was associated with the return of psychotic symptoms (hazard ratio, 5.8).
“The effect of moderate nonadherence (compliance with less than 50% of the medication for more than 2 weeks but less than 4 weeks) was even more striking (hazard ratio 28.5),” say the authors, supporting the view that even partial medication nonadherence has deleterious effects.
The mean time from the beginning of nonadherence until relapse was about 2.5 months.
The researchers also came to similar conclusions when they employed alternative definitions of medication nonadherence.
Given these findings, concluded Dr. Subotnik, “Patients in the early phase of schizophrenia should be cautioned about the possible consequences of partial or relatively brief periods of antipsychotic medication nonadherence.”
By David Douglas
Reuters Health Information
Am J Psychiatry. Posted online January 4, 2011. Abstract