Kornick CA, Santiago-Palma J, Khojainova N, Primavera LH, Payne R, Manfredi PL. Cancer 2001;92:3056-61

Prepared by: : Dr. Sharon Watanabe

Received during: Journal Club on the Tertiary Palliative Care Unit

Abstract:

Background: Therapeutic fentanyl blood levels are reached approximately 12-16 hours after the initial application of transdermal fentanyl patches. For this reason, fentanyl patches should not be used to treat exacerbations of cancer pain. Acute cancer-related pain can be treated with fentanyl administered by continuous intravenous infusion (CII) in combination with patient-controlled analgesia (PCA). Patients then can be switched from intravenous (IV) to transdermal fentanyl once stable pain has been achieved. The objective of the current case series was to evaluate and describe the safety and effectiveness of a method for converting hospitalized patients with cancer-related pain from IV to transdermal fentanyl. Methods: The authors prospectively evaluated 15 consecutive cancer patients during the conversion from IV to transdermal fentanyl. In all patients, a transdermal patch delivering fentanyl at a rate equivalent to that of the final continuous IV infusion was applied. The CII rate was decreased by 50% 6 hours after application of the fentanyl patch and then discontinued after another 6 hours. Demand boluses of IV fentanyl equivalent in dosage to 50-100% of the final CII rate remained available via PCA during the 24 hours after patch application. Pain intensity (on a scale of 0-10), sedation (on a scale of 0-3), and hourly PCA administration (mg/hr) were assessed and recorded immediately prior to application of the fentanyl patch and 6, 12, 18, and 24 hours thereafter. Results: Pain intensity, sedation, and hourly PCA administration appeared to remain stable throughout the transition from IV to transdermal fentanyl. Conclusions: The results of the current study demonstrate that the conversion from IV to transdermal fentanyl can be accomplished safely and effectively using a 1:1 (IV:transdermal) conversion ratio and a two-step taper of the CII over 12 hours.

Comments:

Strengths/uniqueness: This is this first published report describing the conversion of patients from intravenous to transdermal fentanyl for control of cancer pain. The prospective design and systematic assessments are strengths.

Weakness: The study was uncontrolled and unblinded, which may have biased the subjective pain ratings. As transdermal fentanyl may take as long as 48 hours to reach steady state, the 24-hour study period may have been too short to evaluate the success of the conversion.

Relevance to Palliative Care: This paper supports the use of parenteral fentanyl infusion for rapid titration in the setting of unstable cancer pain, followed by conversion to the transdermal route once pain control has been achieved. The Edmonton group has previously reported a similar practice employing subcutaneous fentanyl infusion. The study also supports the procedure of tapering the fentanyl infusion over 12 hours after the first patch application. While using a 1:1 parenteral:transdermal dose conversion ratio is reasonable, close monitoring over the first 72 hours is necessary in case dose adjustment is required.