Prolactin-Raising and Prolactin-Sparing Antipsychotic Drugs and the Risk of Fracture and Fragility Fracture in Patients With Schizophrenia, Dementia, and Other Disorders

Abstract

Patients who require antipsychotic drug treatment are at increased risk of fractures, including osteoporosis-related fragility fractures, for reasons related to demographics, illness-related factors, and treatment-related factors. As examples, patients with dementia may be vulnerable to falls due to cognitive and psychomotor impairment, patients with schizophrenia may be vulnerable to injury related to physical restlessness or physical aggression, and patients receiving antipsychotics may suffer falls related to sedation, psychomotor impairment, bradykinesia, or postural hypotension. Antipsychotics may also increase the risk of fracture through long-term hyperprolactinemia and resultant osteoporosis. A meta-analysis of 36 observational studies conducted in mostly elderly samples found that antipsychotic exposure was associated with an increased risk of hip fracture as well as increased risk of any fracture; the findings were consistent in almost all subgroup analyses. An observational study that controlled for confounding by indication and illness severity found that fragility fractures in patients with schizophrenia were associated with higher daily doses, higher cumulative doses, longer duration of treatment, and prolactin-raising rather than prolactin-sparing antipsychotics; in patients receiving prolactin-raising antipsychotics, the concurrent use of aripiprazole appeared protective. The absolute risks of fracture are unknown and could vary depending on patient age, patient sex, indication for antipsychotic use, nature of the antipsychotic (and associated risk of sedation, psychomotor impairment, bradykinesia, and postural hypotension), daily dose prescribed, duration of antipsychotic exposure, baseline risk of fracture, and other risk factors. Patients should therefore be individually evaluated for risk factors for falls and fractures related to sociodemographic, clinical, and treatment-related risk factors. Patients identified to be at risk should be advised about risk-mitigating strategies. If prolactin-raising antipsychotics are required in the long term, prolactin levels should be monitored and prolactin-lowering strategies should be considered. Osteoporosis should be investigated and managed, if identified, to prevent fragility fractures.