Efficacy of Olanzapine 5 mg versus 10 mg for the Prophylaxis of Chemotherapy-Induced Nausea and Vomiting in Patients Receiving High Emetic Risk Chemotherapy without Neurokinin-1 Receptor Antagonist.

OBJECTIVE: To compare the efficacy and safety of two different dosage levels of olanzapine for the prevention of chemotherapy-induced nausea and vomiting (CINV) in patients receiving high emetic risk chemotherapy. METHODS: This study was a randomized, double-blind, controlled trial designed to show non-inferiority in the efficacy of olanzapine 5 mg compared to 10 mg in patients treated with high dose cisplatin or doxorubicin/cyclophosphamide. Non-inferiority was defined as a lower margin of the 95% confidence interval (95% CI) that not lower than the margin set at -25%. RESULT: A total of 140 patients were randomized to 5 mg group (n=70) or 10 mg group (n=70) of olanzapine. The complete response (CR) rate in the overall phase of olanzapine 5 and 10 mg was 58.6% v 62.9% (95%CI: -20.4, 11.8). The CR rate comparison between olanzapine 5 and 10 mg was 81.4% v 74.3% (95%CI: -6-6, 20.8) and 66.7% v 76.1% (95%CI: -23.5, 6.3) for the acute and delayed phase, respectively. No nausea rates in acute, delayed and overall phase were 70.0% v 68.6% (95%CI: -13.8, 16.6), 45.7% v 48.6% (95%CI: -19.4, 13.6) and 43.5% v 47.9% (95%CI: -19.2, 13.6). The rate of adverse events (AE) including somnolence were not different between the 5 and 10 mg groups. CONCLUSION: The two dosage levels of olanzapine were not different in terms of the efficacy and AE in the prophylaxis of CINV.

Drug Use Evaluation of Letrozole in Breast Cancer Patients at Regional Cancer Hospitals in Thailand.

BACKGROUND: Medication policy development in Thailand is continually promoting rational drug use. Letrozole, an endocrine therapy drug, is usually prescribed for post-menopausal status early and advanced stage breast cancer. After Ministry of Public Health announced Letrozole as compulsory licensed drug in 2009, more breast cancer patients can access to this drug at low cost especially those within universal coverage schemes. To ensure that Letrozole is rationally prescribed, the drug utilization study was conducted. OBJECTIVES: The aim of this study was to describe the appropriate use of Letrozole in breast cancer and the relationship between appropriate use and health benefit schemes. MATERIALS AND METHODS: A retrospective study to evaluate use of Letrozole in breast cancer patients was performed for six months between January - June 2010 in seven regional cancer hospitals, Thailand. All prescriptions of Letrozole were identified from pharmacy dispensing databases and prescription papers. A medical record review was also performed to evaluate appropriate use referring to the drug use evaluation criteria. The approved criterion of this study was referred from the guideline of Thai National Formulary version 2010. RESULTS: There were 681 prescriptions of Letrozole for 254 breast cancer patients with an average age of 58.6 ± 10.0 years. The patients in universal coverage scheme (UCS), civil servant medication benefit scheme (CSMBS) and social security scheme (SSS) were 77.7%, 18.5% and 8.7% respectively. 10.6% were prescribed Letrozole for the first time. Letrozole were prescribed by oncologists (82.8%). The average number of tablets per prescription was 58 ± 10. Calcium supplements were prescribed concomitant with Letrozole for 19.4%. To assess drug use evaluation criteria, 45 prescriptions were excluded because of uncompleted clinical data, 636 prescriptions were evaluated. The study showed 86 prescriptions (13.5%) with inappropriate use including 6 (0.9%) not prescribed for estrogen receptor (ER) and/or progesterone receptor (PR) positive, 31 (4.9%) not prescribed for post-menopausal and 49 (7.7%) not prescribed for an appropriate duration. Appropriate use percentages in different health benefit schemes were similar, 85.7% of CSMBS, 86.4% of SSS and 86.7% of UCS. The relationship between health benefit scheme and appropriate use of Letrozole was not significantly different, χ2 (2, N = 636) = 0.081, p > 0.05. CONCLUSIONS: The study showed inappropriate use in breast cancer patients because of non-compliance with duration, menopausal status and hormone receptor requirements. To prescribe appropriate indication did not referred to the appropriate practice along the treatment. Drug use evaluation proved very useful for detecting the sign of inappropriate use and allows immediate feedback to the stakeholder for developing medication policy in the future. Importantly, there was no significantly difference in appropriate use of Letrozole across health benefit schemes.