In Switzerland, health authorities provide everything online. It has a stupid name if you want to find it using Google:
ElViS. EDIT: Forgot to mention, you have to create an account and that’s something usually reserved to registered health professionals such as physicians and pharmacists in order to avoid everyone from sending in panic hype stuff.
Since an unexpected adverse reaction to a drug or similar might also be a first of its kind, there is no flowchart or the like you could use. Simply fill in the online-form on ElViS should you suspect a known or new more or less adverse reaction and authorities take it from there.
I don’t know how it works in the US but if we get a friendly visit from the local FDA-pendant, they would also give us the required information
. Maybe ask your physician or pharmacist how they handle such affairs?