It could have been a doctor that you read about giving the warning.
I have only heard about a pharmacist - in fact more than one - refusing to fill the prescriptions and warning that if she took such a cocktail of drugs it would kill her.
reaching back into memory - there was a pharmacist who contacted a university expert who conference-called with HKS, Eroshevich and iirc, Anna herself, and warned them jointly and separately that the drugs Eroshevich was attempting to obtain were a ‘death cocktail’ - iirc, this was approximately shortly after Daniel had passed, about the time the deal on the bahamas house was in turmoil and ANS was househunting for the ‘pink house’ and having her electricity shut off - possibly around the time of the clown video?