Overdose
Raloxifene has been studied in clinical trials across a dosage range of 30 to 600 mg/day, and was well-tolerated at all dosages. Pharmacology
Pharmacodynamics
Mechanism of action
Raloxifene is a selective estrogen receptor modulator (SERM) and hence is a mixed agonist and antagonist of the estrogen receptor (ER) in different tissues. It has estrogenic activity in some tissues, such as bone and the liver, and antiestrogenic activity in other tissues, such as the breasts and uterus. Its affinity (Kd) for the ERα is approximately 50 pM, which is similar to that of estradiol. Relative to estradiol, raloxifene has been reported to possess about 8 to 34% of the affinity for the ERα and 0.5 to 76% of the affinity for the ERβ. Raloxifene acts as a partial agonist of the ERα and as a pure antagonist of the ERβ. In contrast to the classical ERs, raloxifene is an agonist of the G protein-coupled estrogen receptor (GPER) (EC50 = 10–100 nM), a membrane estrogen receptor. Clinical effects
Raloxifene has antiestrogenic effects in the mammary glands in preclinical studies. In accordance, raloxifene reduces breast density in postmenopausal women, a known risk factor for breast cancer. It does not stimulate the uterus in postmenopausal women, and results in no increase in risk of endometrial thickening, vaginal bleeding, endometrial hyperplasia, or endometrial cancer. At the same time, raloxifene has minimal antiestrogenic effect in the uterus in premenopausal women.
Raloxifene, already proven effective against Mers and Sars in preclinical tests, has been indicated as effective against SARS-CoV-2 by the “in-silico” research conducted by the consortium which has shown efficacy in countering the replication of the virus in cells. The IP for its use against SARS-CoV-2 has already been protected on May 6 2020 in the name Dompé farmaceutici, Fraunhofer Institute and KU Leuven, to facilitate the largest possible access. Raloxifene would be used in mildly symptomatic COVID-19 patients to halt the spread of infection. This result emerged from the first virtual (in silico) screening conducted on the Consortium’s supercomputers of more than 400.000 molecules (safe-in-man drugs and natural products) made available by Dompé farmaceutici and the partner Fraunhofer (IME) to the Consortium. The molecules were prioritized if in clinical stage or already on the market. 7.000 molecules with certain promising characteristics were tested. References
Further reading
Barrett-Connor E (2001). "Raloxifene: risks and benefits". Ann N Y Acad Sci. 949 (1): 295–303. Bibcode:2001NYASA.949..295B. doi:10.1111/j.1749-6632.2001.tb04036.x. PMID 11795366. S2CID 41412601. Heringa M (2003). "Review on raloxifene: profile of a selective estrogen receptor modulator". Int J Clin Pharmacol Ther. 41 (8): 331–45. doi:10.5414/cpp41331. PMID 12940590. Sporn MB, Dowsett SA, Mershon J, Bryant HU (2004). "Role of raloxifene in breast cancer prevention in postmenopausal women: clinical evidence and potential mechanisms of action". Clin Ther. 26 (6): 830–40. doi:10.1016/s0149-2918(04)90127-0. PMID 15262454. Vogel VG (2009). "The NSABP Study of Tamoxifen and Raloxifene (STAR) trial". Expert Rev Anticancer Ther. 9 (1): 51–60. doi:10.1586/14737140.9.1.51. PMC 2785111. PMID 19105706.