the condition of patients with the disease, although other reports have shown no significant effect, and treatment of scrapie in mice and sheep has also shown no effect. Possible reasons for the lack of an in vivo effect include inefficient penetration of the blood–brain barrier, as well as the existence of drug-resistant prion proteins that increase in number when selected for by treatment with mepacrine. Non-surgical sterilization for women The use of mepacrine for non-surgical sterilization for women has also been studied. The first report of this method claimed a first year failure rate of 3.1%. However, despite a multitude of clinical studies on the use of mepacrine and female sterilization, no randomized, controlled trials have been reported to date and there is some controversy over its use. Pellets of mepacrine are inserted through the cervix into a woman's uterine cavity using a preloaded inserter device, similar in manner to IUCD insertion. The procedure is undertaken twice, first in the proliferative phase, 6 to 12 days following the first day of the menstrual cycle and again one month later. The sclerosing effects of the drugs at the utero-tubal junctions (where the Fallopian tubes enter the uterus) results in scar tissue forming over a six-week interval to close off the tubes permanently. In the United States, this method has undergone Phase I clinical testing. The FDA has waived the necessity for Phase II clinical trials because of the extensive data pertaining to other uses of mepacrine. The next step in the FDA approval process in the United States is a Phase III large multi-center clinical trial. The method is currently used off-label. Many peer reviewed studies suggest that mepacrine sterilization (QS) is potentially safer than surgical sterilization. Nevertheless, in 1998 the Supreme Court of India banned the import or use of the drug, allegedly based on reports that it could cause cancer or ectopic pregnancies. Skin dye During the Second Sino-Japanese War, American Sino-American Cooperative Organization operatives yellowed their skin using mepacrine tablets in order to more closely match the skin color of their Chinese peers. See also Chloroquine Amodiaquine Pamaquine Mefloquine References External links National Institute on Aging (NIA) trial Disulfiram-like drugs Antiprotozoal agents Antimalarial agents Sterilization (medicine) Experimental methods of birth control Acridines Chloroarenes Phenol ethers Aromatic amines Diethylamino compounds