I fully expect they had a full medicine cabinet, stocked for all of life's misadventures, especially if they liked to live quietly at their property. You don't want to be ordering in, or running to town, every time something happens. I imagine most homes would have lots of OTC medications, along with some prescription meds too. I for one have pain meds, anti histamines, sleeping aids, anti-inflammatories, vitamins, lotions and potions for pains and rashes, a first aid kit, bandages, etc, etc, etc. I also have a few prescription meds for my conditions. Some in the fridge, some in the kitchen, and some in the pantry. (Why not the medicine cabinet? I don't really know. Just ease of access as I use them all daily)
The medications in question in this case are just the ones found nearby, on the bench I believe. Thyroid and BP meds are usually taken daily, so I imagine they may have been kept handy and out on the bench. As for the Tylenol, perhaps that was the med being dispensed when the medical episode happened - bad headache, quickly turns to a deadly aneurysm for example.