Impact of 5-HT₃ receptor antagonists on chemotherapy-induced nausea and vomiting: a retrospective cohort study

• Main Authors: Lin Swu-Jane, Hatoum Hind T, Buchner Deborah, Cox David, Balu Sanjeev
• Format: Article
• Language: English
• Published: BMC 2012-07-01
• Series: BMC Health Services Research
• Online Access: http://www.biomedcentral.com/1472-6963/12/215

<p>Abstract</p> <p>Background</p> <p>1^st generation 5-hydroxytryptamine receptor antagonists (5-HT₃ RAs), and palonosetron, a 2^nd generation 5-HT₃ RA, are indicated for the prevention of chemotherapy (CT)-induced nausea and vomiting (CINV) associated with moderately (MEC) and highly emetogenic CT agents (HEC). This study explores the impact of step therapy policies requiring use of an older 5-HT₃ RA before palonosetron on risk of CINV associated with hospital or emergency department (ED) admissions.</p> <p>Methods</p> <p>Patients who received cyclophosphamide post breast cancer (BC) surgery or who were diagnosed with lung cancer on carboplatin (LC-carboplatin) or cisplatin (LC-cisplatin) were selected from PharMetrics’ (IMS LifeLink) claims dataset (2005-2008). Patients were followed for 6 months from initial CT administration for CINV events identified through ICD-9-CM codes. Patients were grouped into those initiated with older, generic 5-HT₃ RAs (ondansetron, granisetron, and dolasetron) and those initiated and maintained on palonosetron throughout study follow-up. CINV events and CINV days were analyzed using multivariate regressions controlling for demographic and clinical variables.</p> <p>Results</p> <p>Eligible patients numbered 3,606 in BC, 4,497 in LC-carboplatin and 1,154 in LC-cisplatin cohorts, with 52%, 40%, and 34% in the palonosetron group, respectively. There was no significant difference between the two 5-HT₃ RA groups in age or Charlson Comorbidity Index among the two MEC cohorts (BC and LC-carboplatin). Among the LC-cisplatin cohort, palonosetron users were older with more males than the older 5-HT₃ RA group (age: 60.1 vs. 61.3; males, 66.9% vs. 56.9%). Compared to the older 5-HT₃ RAs, the palonosetron groups incurred 22%-51% fewer 5-HT₃ RA pharmacy claims, had fewer patients with CINV events (3.5% vs. 5.5% in BC, 9.5% vs. 12.8% in LC-carboplatin, 16.4% vs. 21.7% in LC-cisplatin), and had lower risk for CINV events (odds ratios 0.62, 0.71, or 0.71, respectively; p < 0.05). The BC and LC-carboplatin palonosetron groups experienced 50% and 30% fewer CINV days than the generic 5-HT₃ RA group (p < 0.05).</p> <p>Conclusions</p> <p>Patients with breast or lung cancer initiated and maintained on palonosetron were at significantly lower risk for potentially costly CINV versus those on older 5-HT₃ RAs. Further studies on impact of step therapy policy are warranted in order to minimize the clinical and economic burden of CINV.</p>