FOI release

Freedom of Information request on the yellow card reports following testosterone treatment (FOI 22/580)

Published 14 June 2022

FOI 22/580

20th April 2022

Dear

Thank you for your enquiry dated the 24th March 2022 where you requested further detail on the Yellow Card data for seizures reported whilst on testosterone treatment.

When considering the provided spontaneous Adverse Drug Reaction (ADR) data, it is important to be aware of the following points:

• A reported reaction does not necessarily mean it has been caused by the drug or vaccine, only that the reporter had a suspicion it may have. The fact that symptoms occur after use of a drug or vaccine, and are reported via the Yellow Card scheme, does not in itself mean that they are proven to have been caused by the drug or vaccine. Underlying or concurrent illnesses may be responsible and such events can also be coincidental.

• It is also important to note that the number of reports received via the Yellow Card scheme does not directly equate to the number of people who suffer adverse reactions and therefore cannot be used to determine the incidence of a reaction. ADR reporting rates are influenced by the seriousness of ADRs, their ease of recognition, the extent of use of a particular drug or vaccine and may be stimulated by promotion and publicity about a drug or vaccine. Reporting tends to be highest for newly introduced medicines during the first one to two years on the market and then falls over time. For these reasons the above data should not be used as a basis for determining incidence of side effects. During assessment we take into account of the variable levels of reporting as part of our monitoring procedures.

To note, past medical history is not a mandatory field on a Yellow Card report and therefore is not always provided. Consequently, there may be patients in these reports that have a past medical history of epilepsy but due to the lack of information we cannot determine this.

Firstly, it may be helpful to provide some information on the dictionary that we use when classifying ADR reports. MedDRA (Medical Dictionary for Regulatory Activities) is a clinically validated international medical terminology dictionary. It’s organised by System Organ Class (SOC), divided into High-Level Group Terms (HLGT), High-Level Terms (HLT), Preferred Terms (PT) and finally into Lowest Level Terms (LLT). We use this to code our ADR reports within our database.

Further to your request, I can confirm that up to the 30th March 2022 the MHRA has received a total of 7 UK, spontaneous suspected adverse drug reaction (ADR) reports of the HLGT Seizures (incl subtypes) in patients on testosterone therapy, which can also be seen on the interactive Drug Analysis Print (iDAP) for testosterone.

We have also enclosed Category 1b data on these cases which includes the following data fields relating to the above 7 ADR reports:

• Aggregated patient age
• Aggregated patient sex
• Suspect drug(s)
• Dose of suspect drug
• Route of administration
• Duration of treatment
• Suspected adverse drug reaction(s)
• Outcome of reaction
• Reaction onset times
• Patient medical history
• Year of receipt

Please find the enclosed sheet containing the Category 1b data; Table 1: 1b line listing for these reports, Table 2: patient sex as aggregate values and Table 3: patient age as aggregate values.

I hope the information provided is helpful, but if you are dissatisfied with the handling of your request, you have the right to ask for an internal review. Internal review requests should be submitted within two months of the date of this response; and can be addressed to this email address.

Yours sincerely,

FOI Team,

Vigilance and Risk Management of Medicines Division