Romeo and Juliet both killed themselves with poison, although it was not synthetic drugs. The poison had to be as powerful, some scholars believe that it was hemlock that sealed the fate of the two start crossed love, other are skeptical, but we will probably never know.
The methods and medicines used in Renaissance and Medieval times were very primitive compared to today's standards. medical concepts were magical and demoniacal. With no anesthetics, no knowledge of how the human body and it's functions people many times would do anything they thought would help, not necessarily what worked.
They to cure people from "evil" or the devil, people would literally open up a person's skull and then massage the brain.
Wizards (alchemist) would mix potions, trying to find eternal life , and cures to everything. For years these alchemists tried to find a way to change lead into gold, they as you probably know never suceed.
Alchemists as crazy as they may seem to us were in reality the first chemists discovering metals and mixing them etc.
Here's a poem about something that happen during the Renaissance:
Ring around the rosies,
A pocket full of posies,
We all fall down.
For hundreds of years children sang this song not knowing the horrible meaning behind it.
Song was written about the Bubonic Plague. Horrible living conditions in the cities and town helped the "Black Plague" spread killing thousands and greatly lowered the population of the world. It would cause glands to swell and caused a horrible oder in it's victims.
There was not really a sanitation system in Elizabethan England garbage was left in the street for days, rats would then get into the garbage and the rats would then spread the plague rapidly and in one great wave swept across the country side. No one was safe, but important...