ANAHEIM—Pharmacist assessment of palonosetron use for the prevention of emesis associated with chemotherapy has the potential to capture inappropriate use and result in cost savings, said John P. Jezak, PharmD.
Palonosetron, like the other 5-hydroxytryptamine-3 (5-HT3) antagonists, is indicated for the prevention of emesis with highly and moderately emetic chemotherapy regimens, and although it has not been proven to be superior to other 5-HT3 antagonists for preventing acute emesis, palonosetron has been shown superior for the prevention of delayed emesis, probably owing to its long half-life (approximately 40 hours), notes Jezak, a pharmacy practice resident at Dartmouth- Hitchcock Medical Center, Lebanon, New Hampshire.
5-HT3 antagonists are recommended by the National Comprehensive Cancer Network (NCCN) for use with chemotherapy that has high or moderate risk for emesis, but “the NCCN guidelines don’t really differentiate if there’s a preferential antiemetic drug for a specific clinical situation,” he said.
Palonosetron has an average wholesale price (AWP) that is 50 times greater than ondansetron, so curbing inappropriate use could result in substantial savings, he said.
He conducted a retrospective evaluation of 129 patients (involving 269 encounters) who received palonosetron at the Dartmouth-Hitchcock infusion center over a 2-month period in 2010. Each patient’s chemotherapy regimen was evaluated on the level of acute and delayed emesis potential.
The regimens considered as a risk for delayed-onset emesis, as established by the NCCN, are those containing carboplatin, cisplatin, cyclophosphamide, and doxorubicin. “We decided that any patient that had delayed-onset risk of emesis, based on the four regimens listed in the NCCN criteria, was automatically deemed appropriate for palonosetron use,” said Jezak. “The other qualifier we used is failure of another 5-HT3, such as ondansetron. It would also be appropriate to use palonosetron in this type of patient.”
Therefore, patients receiving chemotherapy regimens considered to possess either low or minimal emetic risk, experiencing no prior 5-HT3 failure, and having no risk for delayed-onset emesis were deemed inappropriate for palonosetron use. Potential interchange of palonosetron with another 5-HT3 antagonist would be appropriate for patients receiving chemotherapy regimens considered to possess either high or moderate emetic risk, experiencing no prior 5-HT3 failure, and having no risk for delayed-onset emesis.
Pharmacist intervention identified 47 cases of inappropriate palonosetron use and 17 cases for a potential 5-HT3 interchange. Preventing inappropriate use had the potential to result in a cost savings of $8792 during the 2-month study period, assuming that the actual drug acquisition cost was 65.93% below AWP.
“Ours is an outpatient facility, so we’re actually billing for this medication; we’re getting reimbursed,” said Jezak. “Each institution would have to consider the full financial impact—what is their reimbursement rate and what is their true cost for the medication?”
He said that the ease of the intervention— a simple phone call—argues for its use. “Our pharmacists are already entering the orders for these medications, so it’s just the matter of picking up the phone and suggesting the use of a medication based on the emetic risk and the patient’s history,” he said.