These include tamoxifen, letrozole, and anastrozole. Selective estrogen receptor modulators, including raloxifene, tamoxifen and toremifene are banned. Raloxifene has a lower risk of thromboembolism than tamoxifen. Daily use of tamoxifen or raloxifene reduce the risk of breast cancer in high-risk women. The aromatase inhibitor aminoglutethimide induces the metabolism of tamoxifen. Clomifene seems to be less effective than tamoxifen or raloxifene. The advantage of raloxifene over the triphenylethylene tamoxifen is reduced effect on the uterus. Its effectiveness is approximately equivalent to that of antiestrogen therapy with tamoxifen or aromatase inhibitors. Other SERMs, like raloxifene, are structurally distinct from tamoxifen and other triphenylethylenes. In those with severe pain tamoxifen or danazol may be used. QT prolongation was also observed with very high doses of tamoxifen. Acute overdose of tamoxifen has not been reported in humans. There is no specific antidote for overdose of tamoxifen. An experimental drug was reported which is a ferrocenyl version of tamoxifen. Tamoxifen and its metabolites undergo conjugation, including glucuronidation and sulfation.