Amifostine before chemotherapy: improved tolerance profile of the subcutaneous over the intravenous route.

Abstract

The i.v. administration of the cytoprotective agent amifostine is associated with reversible clinical hypotension, protracted emesis, and malaise in a various percentage of patients. We evaluated, prospectively, whether the s.c. route is a better tolerated alternative to the i.v. route in patients receiving chemotherapy. Fifty-nine patients treated with "once every 2 weeks" regimens received 1000 mg of amifostine i.v. before chemotherapy. Patients who developed protracted vomiting and malaise and/or clinical hypotension for two consecutive i.v. administrations received the same dose of amifostine s.c. for the subsequent cycles (i.v./s.c. study). In an additional cohort of 12 patients (s.c. study), 1000 mg of amifostine were given s.c. since the first chemotherapy cycle. In the i.v./s.c. study, 8 (13.5%) patients showed protracted emesis/malaise and/or clinical hypotension during the first two cycles. An additional 4 (6.6%) patients developed similar side effects during the subsequent cycles. Switching to the s.c. route, an improved tolerance was noted. In the s.c. study, a total of 76 injections was administered. Protracted vomiting or clinical hypotension was absent, and this tolerance profile was significantly better than the i.v. one (P = 0.001). There were no other systemic side effects related to the s.c. administration. Amifostine, at a dose of 1000 mg, is better tolerated when administered s.c. Switching to the s.c. route in patients with poor tolerance using the i.v. administration allows the continuation of cytoprotection with minor side effects. Although preliminary, 1000 mg of amifostine effectively protected against the lower, still more frequently administered doses of chemotherapy given once every 2 weeks.