The British Fertility Society (BFS) understands the concern that some women must have regarding the withdrawal of this drug. The BFS would like to reassure patients on two main points:
1. On the evidence we have at the moment we do not believe that use of this drug constitutes any threat to health.
2. Patients should be reassured that changing to a different product in the middle of treatment will not adversely effect the outcome of the fertility treatment.
The BFS agrees with the view of the Committee for Safety of Medicines (CSM) that risks associated with this product are ‘incalculably small’(Reference 1).
· There is no evidence that Metrodin HP, or any other drug used in assisted conception, contains the CJD prion.
· There has been no evidence that any patient has acquired CJD after use of these drugs.
It is not possible to test for the CJD prion in these drugs which is why the company is withdrawing the drug as a precautionary measure.
There are two main types of drug used for IVF treatment. Metrodin HP is one type. This is derived from urine, and has been used for many years with an excellent safety record. The newer IVF drugs are manufactured in the laboratories by a biotechnology (recombinant) process. There are theoretical risks to both processes but these are small (Reference 2). The decision about which drug is used is usually made taking account of the financial differences between the products.
Women who have been taking Metrodin HP will be switched to a recombinant product. Women using drugs other than Metrodin HP are not being advised to change products. Women who have used Metrodin HP in the past are not being recommended to have any tests or further monitoring.
Dr Alison Murdoch, Chair of the BFS said ‘We believe that any risks associated with the use of this drug are theoretical. The CSM themselves say that the risks are ‘incalculably small’. There has never been any link shown between the use of this drug and new-variant CJD, or indeed between any IVF-related technology and CJD. We understand why the CSM have taken this decision, but in practical terms we don’t believe that patients should worry.
Any medical treatment has some associated risk, which the patient should discuss with her clinician before starting treatment. In this case we would back the CSM’s view that the risk to patients is small, but I would urge anyone who has special concerns to contact their fertility specialist’.
Reference 1: For Background information, see the briefing document on the Medicines Control Agency website (http://www.mca.gov.uk)
Reference 2: Prion transmission in blood and urine: what are the implications for recombinant and urinary-derived gonadotrophins? Reichl H, Balen A, Jansen HUMAN REPRODUCTION 17 (10): 2501-2508 2002.