Risperidone treatment may not be associated with an increased risk for osteoporosis-related fractures compared with other atypical antipsychotic medications, according to study results published in Acta Psychiatrica Scandinavica.
Researchers conducted a nationwide cohort study comparing the risk for osteoporosis-related fractures in patients treated with risperidone vs other atypical and typical antipsychotic medications. Investigators specifically evaluated the incidence of hip and nonhip fractures.
Patient data were collected from 5 Swedish national registries. Exclusion criteria included active cancer or pituitary tumors, according to data from the Swedish Cancer Register, or nonopen hip or femur fractures prior to the index exposure date.
The study population included 38,211 patients exposed to risperidone, 60,691 exposed to other atypical antipsychotics, and 17,445 exposed to typical antipsychotics. Mean age of the total cohort was 44±17 years among new users of atypical antipsychotics other than risperidone and 68±21 years among new users of risperidone. Compared with 6.6% of new users of atypical antipsychotics, 53.9% of new risperidone users were aged ≥75 years at the time of initial dispensing.
A total of 18.5% of risperidone users had a dementia diagnosis compared with only 2.0% of other atypical antipsychotics. Schizophrenia was the most common diagnosis among users of typical antipsychotics (6.7%); unipolar or bipolar disorder was most common among users of other atypical antipsychotics (31.6% and 9.3%, respectively). Users of typical antipsychotics (38.1%) had the highest rate of psychiatric hospitalizations within 180 days prior to index exposure.
In the adjusted analyses, investigators found no statistically significant differences in fracture risk in the risperidone group compared with the other atypical antipsychotics group (adjusted hazard ratio [aHR], 1.04; 95% CI, 0.91-1.19). There was also no difference in findings with age-stratified analyses. Among patients receiving typical antipsychotics, there was a 24% statistically significant higher fracture risk, compared with other atypical antipsychotics (aHR, 1.24; 95% CI, 1.07-1.45). After age-stratification, the risk increase remained statistically significant in the age groups of 45 to 64 (aHR, 1.56; 95% CI, 1.05-2.32) and ≥65 years (aHR, 1.21; 95% CI, 1.03-1.43).
Researchers found no statistically significant difference in fracture risk for risperidone compared with other atypical antipsychotics among patients who were treatment-naive; typical antipsychotics were associated with a statistically significant risk increase in an aggregated analysis (aHR, 1.25; 95% CI, 1.07-1.47).
Compared with other atypical antipsychotics, patients receiving risperidone did not experience a statistically significant higher risk for nonhip or femur fractures, although a moderately increased risk was noted in patients aged ≥65 years.
Study limitations included possible confounding because of the observational nature of the study, and potentially incomplete data regarding patient medication use as information was only available on prescription dispensing, not use or discontinuation.
“Results suggest that risperidone use is not associated with an elevated risk [for] osteoporosis-related fracture compared with other atypical antipsychotic agents,” the researchers concluded.
Disclosure: This study was supported by Janssen Research and Development. Please see the original reference for a full list of authors’ disclosures.
Clapham E, Bodén R, Reutfors J, et al. Exposure to risperidone versus other antipsychotics and risk of osteoporosis-related fractures: a population based study [published online September 23, 2019]. Acta Psychiatr Scand. doi:10.1111/acps.13101