AMSTERDAM – A large multinational study found that one in five adult patients with schizophrenia switched medications within the previous 12 weeks, mostly because of inadequate symptom control as one-third reported a relapse on the initial drug.
Tolerability issues also were important and differed between first- and second-generation antipsychotics, reported Dr. Beata Galinska-Skok of the Medical University of Bialystok in Choroszcz, Poland.
“In the long-term management of schizophrenia, around one-third of patients treated with antipsychotic drugs change their medication every year. There is a need to better understand the dynamics of switching in real-world conditions. We performed a naturalistic multinational observational survey to evaluate the parameters of treatment discontinuation and substitutions in the management of schizophrenia in every day clinical practice,” Dr. Galinska-Skok said.
The primary objective of the cross-sectional observational study conducted in 11 countries was to identify the frequency of and reasons for switching antipsychotic treatments in patients with schizophrenia. Participating physicians were community- or hospital-based psychiatrists who reflected local psychiatric practices and patient management.
The countries represented were Algeria, Greece, India, Jordan, Lithuania, Mexico, Philippines, Poland, Slovakia, Ukraine, and Vietnam.
The registry population included 23,441 adult patients (mean age 41), of whom 22,126 were analyzable. Of those, 5,128 patients (23.2%) reported a treatment switch in the previous 12 weeks and thus constituted the switch population; 3,130 consented to the study and constitute the analysis population.
The medication that was discontinued in the previous 12 weeks was a second-generation antipsychotic for 55.6% of patients and a first-generation agent for 41.8%, while 2.6% discontinued both types. After the switch, most patients received a second-generation agent (90%) either alone (72.4%) or in combination with a first-generation agent (18.3%). The remainder received a first-generation agent as monotherapy, Dr. Galinska-Skok reported.
Main Reason for Switching: Lack of Efficacy
Physicians could report more than one reason for switching. The survey found the main reason to be inadequate symptom control (79.4%), while the occurrence of adverse events was also common (55.3%). Other reasons frequently cited included poor quality of life (31.7%), relapse on medication (30.1%), poor compliance (25.3%), and patient request (18.3%). Two to six percent reported problems with drug availability, financial or life events, and comorbid medical conditions.
“Over half the changes were motivated by an adverse event,” Dr. Galinska-Skok noted. “The nature of the adverse events differed depending on the class of antipsychotic the patient was taking before the switch. Extrapyramidal symptoms and sedation were the two adverse events that most frequently motivated switching from a first-generation agent. Sedation and weight gain were the two most frequent adverse events motivating switching from a second-generation agent.”
Extrapyramidal symptoms were observed in 36% on a first-generation agent, 12% on a second-generation agent and 28% on the combination. Sedation was observed in 20%, 25% and 23%, respectively. Weight gain was problematic for 10%, 26%, and 23%, respectively. Tardive dyskinesia was observed in 15% receiving combination therapy. Less common were abnormal glucose tolerance, dyslipidemia, and sexual dysfunction.
The study was funded by Sanofi-Aventis.
Dr. Galinska-Skok reported no conflicts relevant to this study.