Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: KEGG:D00950 (Norplant)
 815 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

New trials of Norplant-R-2 were halted in August 1987 because the manufacturer of the silicone component used in the core of the contraceptive implant system discontinued its production. The Dow Corning Corporation decided to stop producing the elastomer used in the 2-rod Norplant-R-2 system after the UN Environmental Protection Agency (EPA) asked for further tests on a component of the catalyst used in the manufacturing process. The EPA request was based on reports that high doses of the substance, 2-ethylhexanoic acid, may cause hepatocellular carcinoma and congenital malformations in laboratory rodents. Dow based its decision on the fact that Elastomer 382 had a very low sales volume and conducting the additional tests would be costly. Its decision will not affect studies using Norplant-R-2. The Population Council has concluded that there is no increased health risk to current users of Norplant-R-2 from the 2-ethylhexanoic acid component and does not recommend removing Norplant-R-2. The US Food and Drug Administration (FDA) does not object to continuation of the clinical trials of Norplant-R-2 now underway. Until researchers can develop an alternate elastomer, all new preintroductory clinical trials of Norplant-R implants will use the Norplant-R capsules. The evidence regarding the toxicology of Elastomer 382 has been reviewed by a toxicology group consultation held by the World Health Organization (WHO) Special Programme for Research, Development and Research Training in Human Reproduction and the USFDA. The WHO review concluded that exposure of women to the maximum possible amount of 2-ethylhexanoic acid in Norplant-R-2 presented no human toxicological risk. When the Population Council evaluated the tests leading to the EPA's request for further studies, it found that in laboratory tests using compounds related to 2-ethylhexanoic acid, the lowest doses causing cancer in rats and mice were, by body weight, 13,000 times as much per day as the total potential amount of the component in Norplant-R-2. The increased incidence of malignant tumors in rats and mice receiving high doses of structurally-related compounds was confined to cancerous growths in liver cells. The Population Council intends to file an application with the USFDA in 1988 for regulatory approval for Norplant-R in the US.
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PMID:Norplant update. 1228 Sep 54