Drug Interactions between Fensolvi and tamoxifen
This report displays the potential drug interactions for the following 2 drugs:
- Fensolvi (leuprolide)
- tamoxifen
Interactions between your drugs
tamoxifen leuprolide
Applies to: tamoxifen and Fensolvi (leuprolide)
GENERALLY AVOID: Long-term androgen deprivation therapy (ADT) can prolong the QT interval. Coadministration of ADT with other agents that may prolong the QT interval could also result in additive effects and an increased risk of ventricular arrhythmias including torsade de pointes and sudden death. The risk may be increased in patients with certain underlying risk factors like congenital long QT syndrome, cardiac disease, and electrolyte disturbances (e.g., hypokalemia, hypomagnesemia). Studies in young men have shown that endogenous serum testosterone levels are inversely associated with QTc (QT interval corrected for heart rate) duration. Clinical trials in men with low serum testosterone levels have reported testosterone administration being associated with a shortening of QTc. Likewise, studies using ADT have shown that it may prolong the QT interval; however, this effect may vary by drug, dose, or even each drug class that can be used to reduce testosterone levels. A clinical study comparing abarelix to a luteinizing hormone-releasing hormone agonist plus nonsteroidal antiandrogen therapy found that both therapies prolonged the mean Fridericia-corrected QT interval (QTcF) by more than 10 msec from baseline. Approximately 20% of patients in both groups had either changes from baseline QTc of >30 msec or end-of-treatment QTc values >450 msec. Similarly, a study comparing degarelix to leuprolide found that approximately 20% of patients on each drug had QT/QTc intervals >450 msec after 1 year of treatment. From baseline to end of study, the median change in QTcF was 12.3 msec for degarelix and 16.7 msec for leuprolide. Some drugs used to lower testosterone levels may also have other side effects that can predispose a patient to QT prolongation and torsade de pointes. For example, inhibitors of 17 alpha-hydroxylase/C17,20-lyase (CYP17) like abiraterone may cause hypokalemia as a result of increased mineralocorticoid levels. Clinical data on ADT prolonging the QT interval in women and children are lacking.
MANAGEMENT: The benefits of androgen deprivation therapy (ADT) should be carefully assessed against the potential risk in patients receiving other drugs known to prolong the QT interval. Electrolyte abnormalities should be corrected prior to initiating therapy, and monitoring of electrocardiograms and electrolytes may be advisable. The manufacturer's labeling as well as current clinical guidelines should be consulted for monitoring recommendations.
References
- (2002) "Product Information. Lupron (leuprolide)." TAP Pharmaceuticals Inc
- (2001) "Product Information. Zoladex (goserelin)." Astra-Zeneca Pharmaceuticals
- (2001) "Product Information. Trelstar (triptorelin)." Pharmacia and Upjohn
- (2002) "Product Information. Eligard (leuprolide)." Sanofi Winthrop Pharmaceuticals
- (2003) "Product Information. Plenaxis (abarelix)." Praecis Pharmaceuticals Inc
- Cerner Multum, Inc. "UK Summary of Product Characteristics."
- (2010) "Product Information. Vantas (histrelin)." Endo Pharmaceuticals (formally Indevus Pharmaceuticals Inc)
- (2013) "Product Information. Firmagon (degarelix)." Ferring Pharmaceuticals Inc
- Krishna KB, Fuqua JS, rogol ad, et al. (2019) "Use of gonadotropin-releasing hormone analogs in children: update by an international consortium." Horm Res Paediatr, 91, p. 357-72
- Lazzerini PE, Bertolozzi I, Acampa M, et al. (2023) Androgen deprivation therapy for prostatic cancer in patients with torsades de pointes. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7239032/
- Gagliano-Juca T, Travison TG, kantoff pw, et al. (2018) "Androgen deprivation therapy is associated with prolongation of QTc interval in men with prostate cancer." J Endocr Soc, 2, p. 485-96
- Gheorghe GS, Hodorogea AS, Ciobanu A, Nanea IT, Gheorghe ACD (2021) "Androgen deprivation therapy, hypogonadism and cardiovascular toxicity in men with advanced prostate cancer." Curr Oncol, 28, p. 3331-46
- (2023) "Product Information. Firmagon (degarelix)." Ferring Pharmaceuticals Pty Ltd
- (2020) "Product Information. Firmagon (degarelix)." Ferring Pharmaceuticals Inc
Drug and food interactions
tamoxifen food
Applies to: tamoxifen
GENERALLY AVOID: Due to their estrogenic effect, isoflavones present in soy such as genistein and daidzein may stimulate breast tumor growth and antagonize the antiproliferative action of tamoxifen. Supportive data are derived primarily from in vitro and animal studies. In vitro, low concentrations of these phytoestrogens have been found to promote DNA synthesis and reverse the inhibitory effect of tamoxifen on estrogen-dependent breast cancer cell proliferation. In contrast, high concentrations of genistein greater than 10 microM/L have been found to enhance tamoxifen effects by inhibiting breast cancer cell growth. It is not known if these high concentrations are normally achieved in humans. Plasma concentrations below 4 microM/L have been observed in healthy volunteers given a soy diet for one month or large single doses of genistein. These concentrations are comparable to the low plasma concentrations associated with tumor stimulation reported in animals. In a study of 155 female breast cancer survivors with substantially bothersome hot flashes, a product containing 50 mg of soy isoflavones (40% to 45% genistein; 40% to 45% daidzein; 10% to 20% glycitein) taken three times a day was found to be no more effective than placebo in reducing hot flashes. No toxicity or recurrence of breast cancer was reported during the 9-week study period.
Green tea does not appear to have significant effects on the pharmacokinetics of tamoxifen or its primary active metabolite, endoxifen. In a study consisting of 14 patients who have been receiving tamoxifen treatment at a stable dose of 20 mg (n=13) or 40 mg (n=1) once daily for at least 3 months, coadministration with green tea supplements twice daily for 14 days resulted in no significant differences in the pharmacokinetics of either tamoxifen or endoxifen with respect to peak plasma concentration (Cmax), systemic exposure (AUC), and trough plasma concentration (Cmin) compared to administration of tamoxifen alone. The combination was well tolerated, with all reported adverse events categorized as mild (grade 1) and none categorized as serious or severe (grade 3 or higher) during the entire study. Although some adverse events such as headache, polyuria, gastrointestinal side effects (e.g., constipation, dyspepsia), and minor liver biochemical disturbances were reported more often during concomitant treatment with green tea, most can be attributed to the high dose of green tea used or to the caffeine in green tea. The green tea supplements used were 1000 mg in strength and contained 150 mg of epigallocatechin-3-gallate (EGCG), the most abundant and biologically active catechin in green tea. According to the investigators, the total daily dose of EGCG taken by study participants is equivalent to the amount contained in approximately 5 to 6 cups of regular green tea. However, it is not known to what extent the data from this study may be applicable to other preparations of green tea such as infusions, since the bioavailability of EGCG and other catechins may vary between preparations.
MANAGEMENT: Until more information is available, patients treated with tamoxifen may consider avoiding or limiting the consumption of soy-containing products. Consumption of green tea and green tea extracts during tamoxifen therapy appears to be safe.
References
- Therapeutic Research Faculty (2008) Natural Medicines Comprehensive Database. http://www.naturaldatabase.com
- Braal CL, Hussaarts KGAM, Seuren L, et al. (2020) "Influence of green tea consumption on endoxifen steady-state concentration in breast cancer patients treated with tamoxifen." Breast Cancer Res Treat, 184, p. 107-13
Therapeutic duplication warnings
No warnings were found for your selected drugs.
Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.
See also
Drug Interaction Classification
Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan. | |
No interaction information available. |
Further information
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