Dose-effect relationship of dexamethasone on Karnofsky performance in metastatic brain tumors: a randomized study of doses of 4, 8, and 16 mg per day.

The purpose of this study was to determine whether lower doses of dexamethasone for treatment of brain tumor edema are as effective as the conventional dose of 16 mg/d. We consecutively executed two double-blind randomized trials in patients with CT-proven brain metastasis and Karnofsky scores of 80 or less. In the first series, we compared 8 mg dexamethasone per day versus 16 mg/d; in the second series, 4 mg/d versus 16 mg/d. Standardized evaluation of quality of life and side effects took place at days 0, 7, 28, and 56. We randomized a total of 96 patients and evaluated eighty-nine. The Karnofsky score improved in the 8-mg group, which had improvement of 8.0 +/- 10.1 (mean +/- SD) points at day 7 versus 7.3 +/- 14.2 points in the 16-mg group. In the second series, the 4-mg group had improvement of 6.7 +/- 11.3 points at day 7 and 7.1 +/- 18.2 points at day 28 versus 9.1 +/- 12.4 and 5.6 +/- 18.5 points in the 16-mg group. Toxic effects occurred more frequently in the 16-mg group (p < 0.03). We conclude that administration of 4 mg dexamethasone per day for treatment of brain tumor edema results in the same degree of improvement as does administration of 16 mg/d after 1 week of treatment in patients who have no signs of impending herniation. Toxic effects are dose-dependent and, during a 4-week period, occurred more frequently in patients using 16 mg/d.(ABSTRACT TRUNCATED AT 250 WORDS)