Y Jing

Utilization, price, and spending trends for antidepressants in the US Medicaid Program

BACKGROUND Antidepressants are often used in the treatment of major depressive disorder and other mental illnesses, and constitute one of the most widely prescribed and costly medication classes in the US Medicaid Program. However, antidepressant utilization and price patterns within this market have not yet been adequately characterized. OBJECTIVES This study was undertaken to analyze antidepressant drug utilization and price trends and to quantify market-share competition in Medicaid. METHODS Quarterly utilization and payment data were retrieved from the national Medicaid pharmacy claims files provided by the Centers for Medicare & Medicaid Services. Quarterly per-prescription prices were estimated by dividing the payment amounts by the number of prescriptions. Descriptive time series analysis was conducted to assess the trends of utilization, expenditures, market shares, and prices from January 1991 through December 2005, for 3 major antidepressant subclasses--Selective Serotonin Reuptake Inhibitors (SSRIs), Tricyclic Antidepressants, and Other Antidepressants--as well as for individual agents within these subclasses. Using exponential smoothing models, 3-year market-share forecasts were produced. RESULTS From 1991 to 2005, the total number of antidepressant prescriptions rose 380% from 6.82 million to 32.72 million. Total expenditures on antidepressants increased from

Exposure to potentially dangerous drug-drug interactions involving antipsychotics.

159 million in 1991 to

Drug Safety Surveillance in China and Other Countries: A Review and Comparison

2.26 billion in 2004, then decreased to

Utilization and spending trends for antiretroviral medications in the U.S. Medicaid program from 1991 to 2005.

1.99 billion in 2005, following the entry of lower-priced generic fluoxetine in 2001 and generic paroxetine in 2003. The payment market share for the SSRIs increased from 40% in 1991 to 82% in 1997, then decreased to 64% in 2005. It is projected to be 64% (95% confidence interval [CI]: 51-77%) in 2008 quarter 4. CONCLUSIONS Increases in antidepressant drug expenditures were primarily because of rising utilization; however, there was also some increase in average price per prescription for many of the antidepressants studied. Switching to generic drugs may offer significant cost-saving potential.

MH2 ECONOMIC AND CLINICAL CONSEQUENCES ASSOCIATED WITH POTENTIAL DRUG-DRUG INTERACTIONS BETWEEN ANTIPSYCHOTICS AND CONCOMITANT MEDICATIONS IN PATIENTS WITH SCHIZOPHRENIA

OBJECTIVE Antipsychotic drug therapy is the cornerstone of treatment of persons with schizophrenia. Because most antipsychotics are metabolized by the hepatic cytochrome P450 system, concomitant use of an antipsychotic and medications that are competitively metabolized by the same system may cause a potentially harmful drug-drug interaction. This study used a large states Medicaid claims database to examine the proportion of patients exposed to such interactions and the risk factors associated with exposure. METHODS Claims from January 2000 through December 2003 for adult patients with a diagnosis of schizophrenia and at least one prescription for an antipsychotic (N=27,909) were examined for pairs of medications identified as potentially causing moderate or severe adverse drug effects. Logistic regression models were estimated to determine potential risk factors associated with exposure to the interaction pairs. RESULTS A total of 6,417 (23%) patients were exposed to 14,213 potentially harmful interactions; 4,725 patients had at least one exposure from the same pharmacy, and 4,032 patients were exposed by the same physician. The greatest number of exposures (N=1,353) to potentially harmful combinations involved olanzapine and haloperidol. Patients prescribed risperidone were most likely to be exposed to an interaction (13.1%), followed by patients prescribed olanzapine (10.3%), quetiapine (3.3%), and clozapine (3.2%). A higher risk of exposure was associated with being female (odds ratio [OR]=.94), being white (OR=1.43), having depression (OR=1.21), or having impulse-control disorder (OR=1.98). CONCLUSIONS Interventions by physicians and pharmacies to reduce the prescribing and dispensing of potentially harmful pairs of medications to patients with schizophrenia are recommended.

PHP34 PRINCIPAL COMPONENTS ANALYSIS OF DRUG UTILIZATION AND EXPENDITURETRENDS FOR MAJORTHERAPEUTIC CLASSES IN U.S. MEDICAID PROGRAMS

Abstract Objectives Drug safety and postmarketing surveillance have become important public health issues in China. This study reviews the relatively new drug safety surveillance system in China and compares it with the systems in the United States and Europe. Methods An extensive literature review was conducted in the following four areas: 1) the organizational structure of the State Food and Drug Administration (SFDA) in China; 2) the development of an adverse drug reaction (ADR) monitoring system in China; 3) regulatory issues related to drug safety in China; and 4) similarities and differences between drug safety surveillance in China and surveillance in the United States and Europe. Results The SFDA oversees an extensive network of drug safety “watchdogs,” including the China National Center for ADR Monitoring and 32 regional centers throughout China. Chinas system has faced a number of recent challenges. It has had to respond quickly to the withdrawal of various high-profile drugs like Vioxx (rofecoxib) and Baycol (cerivastatin) from other markets. Together with Chinas Ministry of Health, the SFDA has faced several unique drug safety events. Three of those events, involving the injectable form of the heartleaf houttuyinia herb (Yu Xing Cao), Armillarisni A injections, and clindamycin glucose infusions (Xinfu), are discussed. The rapid development of drug safety surveillance in China is manifested in extensive organizational structure, development of large databases, and laws and regulations supporting drug safety. The two major laws are the China Drug Administration Law issued in February 2001 and the Regulation for the Administration of ADR Reporting and Monitoring issued in March 2004. The study also discusses and compares recent developments in drug safety surveillance in the United States and the European Union. These developments will most likely have implications for the Chinese system in the near future. Conclusions While postmarketing surveillance guidelines are not yet available in China, we fully expect their eventual issuance after adaptation to the particular culture and clinical practices in China.

PMH15 ANALYSIS OF POTENTIAL DRUG-DRUG INTERACTION PAIRS ASSOCIATED WITH ANTIPSYCHOTICS AMONG MEDICAID PATIENTS WITH SCHIZOPHRENIA OR BIPOLAR DISORDER

BackgroundHIV/AIDS incidence and mortality rates have decreased in the U.S. since 1996. Accompanying the longer life spans of those diagnosed with the disease, however, is a tremendous rise in expenditures on medication. The objective of this study is to describe the trends in utilization of, spending on, and market shares of antiretroviral medications in the U.S. Medicaid Program. Antiretroviral drugs include nucleoside reverse transcriptase inhibitors (NRTIs), protease inhibitors (PIs), nonnucleoside reverse transcriptase inhibitors (NNRTIs), and fusion inhibitors (FIs).MethodsUtilization and payment data from 1991 to 2005 are provided by the Centers for Medicare & Medicaid Services. Descriptive summary analyses were used to assess quarterly prescription numbers and amounts of payment.ResultsThe total number of prescriptions for antiretrovirals increased from 168,914 in 1991 to 2.0 million in 1998, and 3.0 million in 2005, a 16.7-fold increase over 15 years. The number of prescriptions for NRTIs reached 1.6 million in 2005. Prescriptions for PIs increased from 114 in 1995 to 932,176 in 2005, while the number of prescriptions for NNRTIs increased from 1,339 in 1996 to 401,272 in 2005. The total payment for antiretroviral drugs in the U.S. Medicaid Program increased from US

PMH23 A COMPARISION OF HEALTH CARE UTILIZATION AND COST OF CHILDREN AND ADOLESCENTS WITH BIPOLAR DISORDER TREATED WITH ATYPICAL ANTIPSYCHOTIC MONOTHERAPYVERSUS MOOD STABILIZER MONOTHERAPY

30.6 million in 1991 to US

PCV30 TREND ANALYSIS OF PRICE AND UTILIZATION OF STATIN DRUGS IN U.S. MEDICAID PROGRAMS

1.6 billion in 2005, a 49.8-fold increase. In 2005, NRTIs as a class had the highest payment market share. These drugs alone accounted for US

MH4 TREATMENT COST AND COMORBIDITIES ASSOCIATEDWITH OBESITY AMONG CHILDREN ANDADOLESCENTSWITH BIPOLAR DISORDER

787.9 million in Medicaid spending (50.8 percent of spending on antiretrovirals). Payment per prescription for each drug, with the exception of Agenerase®, increased, at least somewhat, over time. The relatively expensive drugs in 2005 included Trizivir® (