A safe and effective method for converting patients from transdermal to intravenous fentanyl for the treatment of acute cancer-related pain.

Background: The delayed effects (12-16 hours) of transdermal fentanyl make dose titration difficult during acute exacerbations of cancer pain. Patients at the authors' institution routinely are switched from transdermal to intravenous (IV) fentanyl using a 1:1 (transdermal:IV) conversion during severe episodes of pain.

Methods: The authors evaluated nine consecutive hospitalized patients with cancer who had severe pain for up to 6 days following the conversion from transdermal to IV fentanyl. Pain intensity was rated using an 11-point (0-10) verbal numeric rating scale (NRS). All 9 patients initially reported their pain intensity with movement as >or= 8 during treatment with transdermal fentanyl. Eight patients initially reported their pain at rest as >or= 8. In each patient, all transdermal patches were removed, and a continuous infusion (CI) delivering IV fentanyl at the same hourly rate was initiated simultaneously. Demand boluses of IV fentanyl equivalent in dosage to 50-100% of the CI rate remained available by patient-controlled analgesia (PCA). Pain intensity (0-10), sedation (0-3), and hourly fentanyl requirements (micrograms per hour) were assessed and recorded immediately prior to patch removal and at least once daily after the initiation of IV fentanyl. The CI and demand boluses were titrated whenever necessary on the basis of pain intensity and supplemental PCA use.

Results: All 9 patients reported mild levels (
Conclusions: The conversion from transdermal to IV fentanyl can be accomplished safely and effectively using a 1:1 (transdermal:IV) conversion during acute exacerbations of cancer pain.