Comparative Pharmacology
Head-to-head clinical analysis: NOLVADEX versus SOLTAMOX.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NOLVADEX versus SOLTAMOX.
NOLVADEX vs SOLTAMOX
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
NOLVADEX (tamoxifen citrate) is a nonsteroidal selective estrogen receptor modulator (SERM) that competitively inhibits estrogen binding to estrogen receptors in breast tissue, thereby blocking estrogen-mediated cell proliferation. It also has partial agonist activity in other tissues such as bone and endometrium.
Selective estrogen receptor modulator (SERM). Binds to estrogen receptors, competitively inhibiting estrogen binding. In breast tissue, acts as an antagonist; in bone and cardiovascular system, acts as an agonist.
20-40 mg orally once daily; for breast cancer, 20 mg/day. For adjuvant therapy, 20 mg/day for 5 years. For ductal carcinoma in situ, 20 mg/day for 5 years. For reduction of breast cancer incidence in high-risk women, 20 mg/day for 5 years.
300 mg orally once daily for 5 days, starting on day 1 of menses.
None Documented
None Documented
Tamoxifen: 5-7 days (terminal). N-desmethyltamoxifen (active metabolite): 14 days. Steady-state achieved in 3-4 weeks.
24-36 hours in adults; prolonged in renal impairment (up to 96 hours in ESRD). Steady-state reached in ~5 days.
Primarily fecal (65%) as conjugates; renal excretion accounts for approximately 25% as metabolites and <0.5% as unchanged drug. Biliary elimination contributes 10%.
Primarily renal (80-90% as unchanged drug); biliary/fecal excretion accounts for 10-20%.
Category C
Category C
Selective Estrogen Receptor Modulator
Selective Estrogen Receptor Modulator