Patients with Parkinson’s disease who take antipsychotics have an increased risk of mortality, according to a study presented at the International Parkinson and Movement Disorder Society (MDS) 19th International Congress in San Diego.
Among patients with Parkinson’s, 60% will experience psychosis, and 50% of those diagnosed with psychosis will be treated with antipsychotics. Additionally, 80% of those with Parkinson’s will develop dementia. Antipsychotic use has been linked to increased mortality and morbidity in the general population with dementia, and the researchers wanted to see if this risk extended to Parkinson’s patients.
The study included 7,877 matched pairs with Parkinson’s disease, one of whom was initiating antipsychotics and the other who was not. Participants were matched for age, gender, race, index year, presence of dementia, time from dementia diagnosis to index date, time from Parkinson’s diagnosis to index date, delirium, hospitalization, 3-catefory Charlson’s Comorbidity Index, and new non-psych medications within 14 days of antipsychotic prescription. The primary outcome was 180-day mortality rates.
Participants who took any antipsychotic were 2.35 times more likely to die within 180 days compared with those not taking any antipsychotics. Patients taking typical antipsychotics had a higher risk of mortality (HR=3.65) compared with those taking atypical antipsychotics (HR=2.26). The risk for specific typical antipsychotics was as follows: haloperidol (HR=5.08) and other typical (HR=1.82). The risk for specific atypical antipsychotics was as follows: olanzapine (HR=2.79), quetiapine (HR=2.16), risperidone (HR=2.46), and other atypical (HR=1.19).
Quetiapine was the most commonly prescribed antipsychotic in the study, making up approximately 70% of prescriptions. While its increased risk of mortality was relatively low compared to other antipsychotics, it still more than doubled mortality risk compared with no antipsychotic use.
The results of this study suggest that clinicians should carefully consider the risks and benefits when prescribing antipsychotics to patients with Parkinson’s disease.
The researchers suggest that further studies investigate specific cause of death in antipsychotic users in order to improve care. Additionally, further research should be made into non-pharmacologic methods of managing psychosis among Parkinson’s disease patients.