Congress Abstracts 2003

16

THE TREATMENT OF ADVANCED PROSTATE CANCER WITH KETOCONAZOLE. Patricia Fox, RN, MA, AOCN^®, and Christine Liebertz, RN, CS, MSN, AOCN^®, Memorial Sloan-Kettering Cancer Center, NY.

Ketoconazole, a well-known antifungal agent, is used as second-line hormone in the treatment of hormone-sensitive metastatic prostate cancer. Ketoconazole lowers serum testosterone levels by blocking adrenal steroidogenesis that is unaffected by luteinizing hormone-releasing-hormone analogue or orchiectomy. Response rates of 63% and a median duration of efficacy of 3.4 months have been reported. The oncology nurse plays a critical role in caring for men receiving ketoconazole for prostate cancer. Patient education regarding the administration of ketoconazole, action, side effects, and ongoing evaluation of adverse effects are of paramount importance. The oncology nurse must be knowledgeable regarding the role of ketoconazole in prostate cancer and familiar with the mechanism of action and toxicity profile of the drug.

At this NCI-designated comprehensive cancer center, the nursing staff developed a fact card to provide essential information patients need to know while taking this medication. Mechanism of action, usual dosage, optimal method of administration, side effects, and potential drug and food interactions are described. Ketoconazole is a potent inhibitor of the cytochrome P450 3A4 enzyme system. Co-administration with certain drugs may result in increased plasma concentrations of these drugs with subsequent prolonged therapeutic or adverse effects of these agents. Some medications are absolutely contraindicated in conjunction with ketoconazole therapy; others need close monitoring for toxicity secondary to concomitant administration.

Ketoconazole is initiated at a dose of 200 mg TID. The dose is doubled if the prostate specific antigen (PSA) continues to increase or if it increases after an initial response. The addition of hydrocortisone twice daily is expected to lessen the likelihood of adrenal insufficiency at this higher dose. Side effects include fatigue, nausea and vomiting, abnormal liver function, impotence, skin reactions, and diarrhea. Patients are instructed on symptoms to report and encouraged to call with any concerns.

Given the complexity of caring for these patients, the oncology nurse must be well informed. This presentation will elaborate on the use of ketoconazole in the treatment of prostate cancer and the nurse’s role in educating patients along with the nursing management strategies developed at this center.