Few pharmacies can afford to have unused and/or out-of- date medications sitting in their inventories. If the medications are oncolytic agents such as temozolomide (Temodar; Schering-Plough) or erlotinib (Tarceva; Genentech/OSI Pharmaceuticals), the problem is that much more acute.

Paul Lofholm, PharmD, who operates a 2500-square-foot pharmacy in Marin County, Ca., deals with this issue. Oncolytic agents might be included in the Ross Valley Pharmacy inventory two or three times a year. "Erlotinib comes in a bottle of 30 and if I dispense 14 of them I have $1500 worth of drug sitting on a shelf," he said.

Ross Valley Pharmacy is near the local hospital and an oncology group, said Lofholm, who is also a professor of clinical pharmacy at the University of California, San Francisco. "We are a community pharmacy and 90 percent of our business is prescriptions," he said. Of that prescription business, only 1 percent involves oral oncology drugs, up to 5 percent if hospice patients are included.

Intricacies of dispensing

There are extraordinary barriers to dispensing some of these drugs," Lofholm said. For example, filling a prescription for aprepitant (Emend; Merck) may seem simple enough, but it can be dispensed only with dexamethasone and only when the patient has had methotrexate administered in the oncologist's office. Furthermore, all three agents must be billed on the same day.

"So if the patient goes to get their chemotherapy we cannot bill their antinausea medication until the oncologist bills for the methotrexate," Lofholm said. If the physician failed to write the dexamethasone prescription or if the timing of the billing is off, Lofholm's patient is left nauseated while the pharmacy technician tries to sort it out.

Oral agents with a parenteral counterpart can be billed under Medicare Part B, "if the pharmacist knows how to bill it. Most pharmacists don't bill Medicare Part B and never have. They were never taught how to do it," Lofholm said.

Oral oncolytics that aren't billable under Medicare Part B often are covered by Medicare Part D. Then the health plans weigh in. In fact, the advent of Medicare Part D is thought to have speeded the development of oral cancer drugs to its current dizzying pace. (See "The pipeline: Oral antineoplastic agents".)

As the number of available oral cancer medications continues to increase, pharmacists must work to navigate the dispensing, billing, and reimbursement challenges that come with them. There is also concern about the safety of handling cytotoxic drugs on a regular basis.

"There are multiple drugs, accessing of multiple benefits and patient assistance programs, and a disease that is continuously morphing with the shortest durations of therapy. There is also a sense of urgency to get the drug to the patient," said Burt Zweigenhaft, CEO of Oncomed, a New York-based bio-oncology pharmacy. "It is not unusual to have multiple agents, and the reimbursement is the toughest out there." He added that since the margins on these drugs are so slim, pharmacies want to make sure they will be reimbursed.

Some of the agents are under limited distribution and may be difficult for community and retail pharmacies to obtain. "Manufacturers don't put limited distribution agreements in place so they can restrict the drug and raise the margins. They are trying to define competency, and if you don't have those competencies, they are not going to give you the drug," Zweigenhaft said.

The packaging of some agents also presents a challenge. According to Lofholm, he may have a patient who needs the first 14- or 21-day cycle of a drug that comes only in 100-count packages. If the physician changes that patient's regimen or the drug isn't tolerated, Lofholm is stuck with the remainder.

"When we dispense orals we look at dispensing weekly rather than monthly," Zweigenhaft said. If the patient pays $4,000 for a month of treatment only to find out the drug isn't tolerated after a week, $3,000 of the patient's drug benefit is wasted.

Additionally, as the average cost of oral cancer treatment approaches $43,000 and some drugs, such as trastuzumab (Herceptin; Genentech), costing $70,000, patients hit the Medicare Part D "donut hole" almost immediately. Others are turning to their pharmacists for help with patient assistance programs.