Background: COX-2 inhibitors (COX-2i) have been reported to have beneficial effects on schizophrenia. This observational study assesses the association between exposure to COX-2i or/and NSAIDs and schizophrenia deterioration.
Methods: We conducted a case-control study within a cohort (n=3,485) of antipsychotic users with a schizophrenia diagnosis (ICD-9=295.x) in IMS-Lifelink, a US claims database. Case events indicating exacerbation of schizophrenia were: switching antipsychotic medication, starting combination therapy, using parenteral antipsychotics or an increasing dose. For each case one control was selected. Exposure to COX-2i/NSAIDs (current/recent/none) and cumulative exposure in Defined Daily Doses 90 days before the index/event date were assessed. Age, sex and co-medication were evaluated as confounders. Logistic regression analysis was used to assess the association.
Results: 1,443 case events occurred. For current use, no benefit on schizophrenia case events from exposure to COX-2i was found (adjusted OR 1.16; 95% CI 0.83-1.62). Instead, recent COX2i use with a duration of 0 to 93 days was associated with an increased risk for schizophrenia deterioration (adjusted OR 2.56; 95% CI 1.35-4.87). This association was strongest in rofecoxib. No relation was found for NSAIDs.
Conclusion: The use of COX-2i was not associated with a decreased risk for schizophrenia deterioration in this population.