Changing "Medications that affect heart rate"

I just purchased an Apple Watch 7 to link with my iPhone 7+. Both devices are up-to-date.

I apologise for being a bit obscure, but I need to change a setting related to "Medications that affect heart rate". I was setting-up something related to BP or ECG or whatever on my watch and, from memory, it told me to do so on my iPhone. At some point I was asked whether I am taking any mediations that affect heart rate. I answered No and then later realised that I need to change it to Yes, in respect of a calcium channel blocker.

I cannot do it on my iPhone 7 'Settings' as there is no facility to make the change, even though it is showing 0. I cannot find how to do it on my Watch.

Can anyone provide advice on what I need to do and on which device?

Thankyou for you help.

Regards

Peter