§ Mr. Carter-Jonesasked the Secretary of State for Social Services if, in view of the late discovery of the longterm effects of stilboestrol on the reproductive tracts of female children of women given this drug, the Committee on Safety of Medicines has established guidelines for the use of new drugs which may have delayed side effects; and if he will make a statement.
§ Dr. Vaughan[pursuant to his reply, 18 February 1981, c. 162.]: The licensing authority has issued guidelines for companies on animal tests required for product licence applications. These include carcinogeni-city, reproduction and, in future, mutagenicity studies, which will, as far as the current state of knowledge allows, assist in the identification of any late or delayed hazard of the type associated with stilboestrol. These guidelines take account of the advice of a working party established in 1973 by the Committee on Safety of Medicines (CSM) which gave special attention to the problem of transplacental carcinogenesis.
However, while these tests provide such reassurance as is practicable at the present time, it has to be recognised that no potent drug is completely safe and that the possibility of long-delayed adverse effects cannot be entirely ruled out until there has been extensive clinical use.
The CSM has recently reminded doctors of its support for the view that drugs should not be given during pregnancy unless they are essential.