Hospitalization and cost after switching from atypical to typical antipsychotics in schizophrenia patients in Thailand

Tuanthon Boonlue,1,2 Suphat Subongkot,1,2 Piyameth Dilokthornsakul,3,4 Ronnachai Kongsakon,5 Oraluck Pattanaprateep,6 Orabhorn Suanchang,7 Nathorn Chaiyakunapruk3,8–10 1Clinical Pharmacy Division, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen, Thailand; 2The College of Pharmacotherapy of Thailand, Nonthaburi, Thailand; 3Center of Pharmaceutical Outcomes Research, Department of Pharmacy Practice, Faculty of Pharmaceutical Sciences, Naresuan University, Phitsanulok, Thailand; 4Center for Pharmaceutical Outcomes Research, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO, USA; 5Department of Psychiatry, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand; 6Department of Health Informatics, Ramathibodi Hospital, Mahidol University, 7Department of Pharmacy, Somdet Chaopraya Institute of Psychiatry, Bangkok, Thailand; 8School of Pharmacy, Monash University Malaysia, Selangor, Malaysia; 9School of Population Health, University of Queensland, Brisbane, Australia; 10School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA Background: Several clinical practice guidelines suggest using atypical over typical antipsychotics in patients diagnosed with schizophrenia. Nevertheless, cost-containment policy urged restricting usage of atypical antipsychotics and switching from atypical to typical antipsychotics. Objective: This study aimed to evaluate clinical and economic impacts of switching from atypical to typical antipsychotics in schizophrenia patients in Thailand. Methods: From October 2010 through September 2013, a retrospective cohort study was performed utilizing electronic database of two tertiary hospitals. Schizophrenia patients aged 18 years or older and being treated with atypical antipsychotics were included. Patients were classified as atypical antipsychotic switching group if they switched to typical antipsychotics after 180 days of continual atypical antipsychotics therapy. Outcomes were schizophrenia-related hospitalization and total health care cost. Logistic and Poisson regression were used to evaluate the risk of hospitalization, and generalized linear model with gamma distribution was used to determine the health care cost. All analyses were adjusted by employing propensity score and multivariable analyses. All cost estimates were adjusted according to 2013 consumer price index and converted to US$at an exchange rate of 32.85 Thai bahts/US$. Results: A total of 2,354 patients were included. Of them, 166 (7.1%) patients switched to typical antipsychotics. The adjusted odds ratio for schizophrenia-related hospitalization in atypical antipsychotic switching group was 1.87 (95% confidence interval [CI] 1.23–2.83). The adjusted incidence rate ratio was 2.44 (95% CI 1.57–3.79) for schizophrenia-related hospitalizations. The average total health care cost was lower in patients with antipsychotic switching (–$64; 95$459 to $332). Conclusion: Switching from atypical to typical antipsychotics is associated with an increased risk of schizophrenia-related hospitalization. Nonetheless, association with average total health care cost was not observed. These findings can be of use as a part of evidence in executing prospective cost-containment policy. Keywords: antipsychotic switching, schizophrenia, hospitalization, cost, atypical antipsychotics, typical antipsychotic

Characterization of statin-associated myopathy case reports in thailand using the health product vigilance center database

HMG-CoA reductase inhibitors [statins], a widely prescribed cholesterol-lowering therapy, are associated with muscle-related adverse events. While characteristics of such events are well documented in Western countries, little data exists for the Thai population.The aim of this study was to determine the characteristics of patients, type and dosing of statin, and to identify patterns of drug use that may be associated with such adverse events using the national pharmacovigilance database known as Thai Vigibase.Muscle-related adverse events involving statins in the Thai Vigibase from 1996 to December 2009 were identified. For each report, the following information was extracted: patient demographics, co-morbidities, detailed information of adverse event, detailed information of suspected drug, treatment and outcome, as well as causality assessment and quality of reports. Descriptive statistics were performed for all study variables.A total of 198 cases of statin-associated muscle-related adverse events were identified. Mean age was 61.4 ± 12.4 years of age and 59.6% were female. Simvastatin, atorvastatin, rosuvastatin and cerivastatin were implicated as the suspected drug in 163 (82.3%), 24 (12.1%), 10 (5.1%) and 1 (0.5%) cases, respectively. Rhabdomyolysis accounted for 55.6% of all muscle-related adverse events. Drug interactions known to enhance such toxicity of statins were identified in 40.9% of the total set of reports. Similar to studies from Western countries, fibrates, HIV protease inhibitors, non-dihydropyridine calcium channel blockers, azole antifungals and macrolides were commonly found in such cases. Interestingly, colchicine has been identified as the second most common drug interaction in our database. Case fatality rates were 0.9, 1.6 and 16.7%, when there were 0, 1 and ≥2 interacting drugs, respectively.Characteristics of muscle-related adverse events with statins in the Thai population showed some similarities and differences compared with Western countries. Such similarities included advanced age, female sex, certain co-morbidities and drug interactions. While the majority of interacting drugs are well known, a big proportion of cases of statin-colchicine interaction attributed to long-term use of colchicine in Thailand was noted and should be further investigated. Based on these results, an attempt to avoid dangerous and well-known drug interactions among statin users should be implemented nationwide