ROCHESTER, Minn—Use of transdermal fentanyl(Drug information on fentanyl) (Duragesic) in ambulatory cancer pain patients appears to be safe and effective, Julie E. Hammack, MD, and her colleagues from four North Central Cancer Treatment Group (NCCTG) institutions report.
Dr. Hammack's group performed an open-label pilot study of the agent in 35 patients with moderate cancer pain who had failed conventional opioid analgesia with codeine, oxycodone(Drug information on oxycodone), or pro-poxyphene.
In this 7-day trial, patients received either the 25 or 50 µg/h fentanyl patch, based on their prior daily opioid dose. Patients stopped taking their scheduled analgesics at the start of the study but were permitted to take morphine(Drug information on morphine) or hydromorphone(Drug information on hydromorphone) with or without an NSAID or acetaminophen as needed for breakthrough pain.
Of the 30 evaluable patients, mean pain scores on a visual analogue scale fell from 56 at baseline to 41 at the end of the study. The mean pain scores using a 0-4 categorical scale fell from 2.3 at baseline to 1.6.
"These data suggest that fentanyl was associated with a 24% to 29% mean reduction in the levels of pain compared to baseline," Dr. Hammack says. In addition, mean hours of sleep rose from 5.5 to 7 during the study, a 25% increase (J Pain Symptom Manage 12:234-240, 1996).
These improvements in pain and sleep did not appear to be due to increased use of rescue opioids. An apparent increase in such medications in the first 2 days of the study "likely represents the lag time in achieving analgesic serum levels with transdermal fentanyl," Dr. Hammack says. After the second day on study, the average use of rescue medications decreased.
Nearly half of patients (46%) said they were "satisfied" to "completely satisfied" with their pain relief from transdermal fentanyl; 26% were "somewhat satisfied"; 6% were "not at all satisfied"; and 23% did not respond to the question.
Only two patients discontinued the drug because of fentanyl toxicity, one due to constipation and one to hallucinations. Although stool softeners were not required by the study protocol, the researchers note that "prevention of constipation may be optimized by starting a stool softener or other laxative coincident with fentanyl."
Twenty-five patients (71%) chose to enter the continuation phase of the study, and toxicities during this phase were similar to those seen in the pilot study.
The researchers conclude that the 25 to 50 µg/h patch is a safe starting dosage in these patients, "but likely will require upward titration to obtain optimal analgesia in most patients."
Although transdermal fentanyl is "more expensive than other commonly used opioids with a similar side effect profile," the researchers say, they believe it may prove to be "a useful alternative in patients unable to tolerate oral medications or as a second-line or third-line agent in those with unmanageable adverse effects from other high-potency opioids."
Dr. Hammack's colleagues in the study were Charles Loprinzi, MD, Judith O'Fallon, PhD, and Angela Miser, MB, of the Mayo Clinic; and James Mailliard, MD, Raylene Respond, PharmD, Mary Wilwerding, RN, and Pat Fidler, RN, of Nebraska Oncology Group-Creighton University.
Also, Nicholas Reuter, MD, of the University of Nebraska Medical Center and Associates, Omaha; and John Michalak, of Siouxland Hematology-Oncology Associates, Sioux City, Iowa.
