Long-term observations of patients receiving transdermal fentanyl after a randomized trial

We observed 73 cancer patients receiving transdermal fentanyl for 1-29 (mean 5.5) months immediately after participation in a randomized clinical trial. Of these, 32 received fentanyl until death, 18 were lost to follow-up, 11 required alternative analgesia, and 12 withdrew for other reasons. The median first recorded dose (not necessarily the patient's first fentanyl dose) was 75 microg/h. The median final dose was 100 microg/h. All but 3 patients required <300 microg fentanyl/h. In the 16 who received fentanyl for > or =3 months until death, the median dose was unchanged (100 microg/h) 3 months before death and at death; 8/16 required no dosage change. The incidence of constipation, skin reactions, nausea, and vomiting was low. No significant respiratory depression was associated with fentanyl. Most patients (85%) and investigators (86%) rated the treatment as good or excellent. We conclude that long-term treatment with transdermal fentanyl is safe and acceptable to many cancer patients.