TY - JOUR
T1 - Bioequivalence of 20-mg once-daily tamoxifen relative to 10-mg twice-daily tamoxifen regimens for breast cancer
AU - Buzdar, Aman U.
AU - Hortobagyi, Gabriel N.
AU - Frye, Debra
AU - Ho, Daisy
AU - Booser, Daniel J.
AU - Valero, Vicente
AU - Holmes, Frankie A.
AU - Birmingham, Bruce K.
AU - Bui, Khanh
AU - Yeh, Chiao
AU - Plourde, Paul V.
PY - 1994/1
Y1 - 1994/1
N2 - Purpose: We studied the bioequivalence of a new once-daily regimen of tamoxifen citrate relative to the standard twice-daily regimen of tamoxifen citrate, an established antiestrogenic treatment for breast cancer. Patients and Methods: Of 30 women with breast cancer, 27 completed this open, two-period, crossover randomized trial. During one 3-month period, patients took one standard 10-mg tamoxifen tablet twice daily; during the preceding or following 3-month period, patients took one of the new 20-mg tablets once daily. Pharmacokinetic profiles and safety parameters were assessed at the end of each 3-month treatment period. Results: Overall, measured concentrations of tamoxifen and its principal active metabolite, N-desmethylta-moxifen, remained relatively constant over the 24-hour sampling periods at the end of each treatment sequence. For both compounds, the percentage differences of the geometric means for all pharmacokinetic parameters indicated bioequivalence of the once-daily regimen of tamoxifen relative to the standard twice-daily regimen. Both treatment sequences were well tolerated; reported adverse events occurred at similar frequencies with the two treatment regimens. Conclusion: The 20-mg tamoxifen tablet taken once daily was bioequivalent to the 10-mg tamoxifen tablet taken twice daily, with no difference in relative risk. The once-daily treatment is a simpler regimen and may facilitate compliance, which may enhance therapeutic outcomes during long-term treatment of breast cancer.
AB - Purpose: We studied the bioequivalence of a new once-daily regimen of tamoxifen citrate relative to the standard twice-daily regimen of tamoxifen citrate, an established antiestrogenic treatment for breast cancer. Patients and Methods: Of 30 women with breast cancer, 27 completed this open, two-period, crossover randomized trial. During one 3-month period, patients took one standard 10-mg tamoxifen tablet twice daily; during the preceding or following 3-month period, patients took one of the new 20-mg tablets once daily. Pharmacokinetic profiles and safety parameters were assessed at the end of each 3-month treatment period. Results: Overall, measured concentrations of tamoxifen and its principal active metabolite, N-desmethylta-moxifen, remained relatively constant over the 24-hour sampling periods at the end of each treatment sequence. For both compounds, the percentage differences of the geometric means for all pharmacokinetic parameters indicated bioequivalence of the once-daily regimen of tamoxifen relative to the standard twice-daily regimen. Both treatment sequences were well tolerated; reported adverse events occurred at similar frequencies with the two treatment regimens. Conclusion: The 20-mg tamoxifen tablet taken once daily was bioequivalent to the 10-mg tamoxifen tablet taken twice daily, with no difference in relative risk. The once-daily treatment is a simpler regimen and may facilitate compliance, which may enhance therapeutic outcomes during long-term treatment of breast cancer.
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U2 - 10.1200/JCO.1994.12.1.50
DO - 10.1200/JCO.1994.12.1.50
M3 - Article
C2 - 8270984
AN - SCOPUS:0028088851
SN - 0732-183X
VL - 12
SP - 50
EP - 54
JO - Journal of Clinical Oncology
JF - Journal of Clinical Oncology
IS - 1
ER -