Studying Fentanyl in Patients With Cancer

DISEASE CHARACTERISTICS:

* Diagnosis of cancer
* Inpatient at the Johns Hopkins Hospital Cancer Center undergoing pain treatment with continuous infusion fentanyl citrate for ≥ 5 days

PATIENT CHARACTERISTICS:

* Willing to change to an alternative opioid

PRIOR CONCURRENT THERAPY:

* See Disease Characteristics
* At least 72 hours since transdermal fentanyl citrate administration
* At least 12 hours since transmucosal fentanyl citrate administration
* No known requirement for continued opioid therapy with any fentanyl citrate products after discontinuation of fentanyl citrate therapy