Pfizer Allows Community Pharmacies to Dispense Dofetilide
Dofetilide received FDA-approved labeling in 1999 for the conversion of symptomatic atrial fibrillation or flutter to normal sinus rhythm and for the maintenance of normal sinus rhythm after conversion. The products labeling requires that patients be hospitalized and closely monitored when starting therapy with dofetilide, which can cause deadly heart arrhythmias. Therapy is contraindicated in patients with severe renal impairment or a QT syndrome and during treatment with drugs known to increase the amount of dofetilide in the bloodstream.
Physicians must complete an educational program and join a registry of authorized dofetilide prescribers before ordering the drug for patients. Pfizer initially restricted inpatient distribution of the drug to hospital pharmacies that were designated "confirmed participants" in an approved educational program. All outpatient prescriptions for dofetilide were distributed through a mail-order program run by Stadtlanders Pharmacy (now CVS ProCare Pharmacy).
Lorraine Donagher, marketing manager of Pfizer's cardiovascular disease management team, said during a July 25 meeting with ASHP staff that the original restricted-distribution program for dofetilide worked well, but the process "certainly presented some barriers to patient access."
With the launch of Pfizer's new Tikosyn in Pharmacy System (TIPS), patients who have begun dofetilide therapy while in the hospital may obtain prescription refills for the drug at authorized community pharmacies.
Donagher said the enrollment process for community pharmacies is "totally different" from the process used to register hospitals that dispense the drug.
"There are no real training requirements" for community pharmacies to enroll, Donagher said. Whereas the initial dofetilide dosage is determined by trained health care providers in a hospital setting, community pharmacies will dispense only the maintenance regimen, she explained.
Before dispensing dofetilide, staff at an approved community pharmacy must consult a database to confirm that the prescription was written by a physician who has completed the required training program, Donagher said. The pharmacist must imprint the dofetilide prescription with the special stamp provided by Pfizer and then sign and date the prescription.
Donagher said about 1,100 hospitals and health systems are authorized to dispense dofetilide under Pfizer's original authorization program. The company, she said, hopes to enroll about 10,000 community pharmacies under the new program.
"Physicians are very anxious for [the TIPS program] to happen," Donagher said. She added that Pfizer, in response to physicians' requests, will focus the initial enrollment efforts on pharmacies near hospitals that use large amounts of dofetilide. Donagher noted that enrollment in the TIPS program does not obligate a community pharmacy to dispense dofetilide but allows provision of the drug when the need arises.
Pfizer mailed informational fliers in August urging community pharmacies to enroll in the TIPS program, and Donagher said the company expects those new enrollees to dispense their first prescriptions of dofetilide this month. Authorized pharmacies can obtain the product through the sole authorized wholesaler, AmerisourceBergen, or purchase dofetilide directly from Pfizer.
To request an enrollment and information kit for the TIPS program, community pharmacies should call 877-845-6796.
During an April 26 conference in Indianapolis organized by the National Patient Safety Foundation, physician Robert M. Califf of North Carolina's Duke Clinical Research Institute reported preliminary data illustrating physicians' reactions to the prescribing requirements for the antiarrhythmic drug dofetilide (Tikosyn, Pfizer).
"When dofetilide was approved to go on the market," Califf said, "the decision was made by the FDA that it should not be prescribed except in the hospital and only by doctors who . . . understand the measurements they need to make when they prescribe the drug." These measurements include calculation of a patients creatinine clearance and determination of the QT interval.
But Califf said that an older antiarrhythmic drug, sotalol, causes the same adverse effects as dofetilide but is not part of a restricted-distribution program.
Califf said his reasearch team found that "doctors most of the time prescribe dofetilide correctly, but they don't prescribe dofetilide very much" because of the burdensome requirements. In contrast, "over 70% of the time [physicians] prescribe sotalol incorrectly and dont do any of the things, by and large, that you're supposed to do for safety measurements."