Episode #30: tamoxifen (Soltamox) | Podcast Show Notes
tamoxifen (ta MOKS I fen)
Below will be links for the full Podcast and the Drug Card for tamoxifen along with a brief summary of various points on tamoxifen.
QUESTIONS:
- True or False. When tamoxifen is metabolized the metabolite becomes less potent than tamoxifen itself.
- Which of the following is/are true about tamoxifen? Select all that apply.
- A). Metabolized via the CYP2D6 pathway
- B). Metabolized via the CYP3A4/5 pathway
- C). Has a black box warning for Uterine Malignancies
- D). Has a black box warning for Thromboembolic Events
- E). B, C, and D only.
- Describe the mechanism of action for tamoxifen?
- True or False. Tamoxifen is both cytotoxic and well absorbed.
SUMMARY:
Tamoxifen is a selective estrogen receptor modulator that comes in both a tablet and solution. The tablet comes in a 10 mg and 20 mg strength and the solution comes in a 10 mg/5 mL concentration. Tamoxifen, also known as the brand name Femara, when used in reducing the risk of Breast Cancer in high risk females the dosing is 20 mg once daily for 5 years. When used in treating Breast Cancer the dosing does vary at 20-40 mg once daily. When 40 mg is needed per day the daily dose is divided into separate doses. When tamoxifen is metabolized via the CYP2D6 and CYP3A4/5 pathways the metabolites are 30-100 times more potent than tamoxifen itself. There is a black box warning for Uterine Malignancies and Thromboembolic Events. The monitoring parameters are bone mineral density, lipid panel, CBC with platelets, ophthalmic exam, and for medication adherence. The medication can be taken with or without food.
ANSWERS:
- False. The metabolite of tamoxifen becomes “more” potent (by 30-100 times) than tamoxifen itself.
- A, B, C, and D are correct. E is incorrect because it does not include D
- Tamoxifen selectively and competitively binds to estrogen receptor modulators on tumors. The complex that is produced leads to a decrease of DNA synthesis and an inhibition of the effects of estrogen.
- False. Although tamoxifen is well absorbed it is “not” cytotoxic, it is considered cytostatic since the cells accumulate in the G0 and G1 phases.
PDF of Drug Card: tamoxifen
