Percocet used for pain relief is a narcotic medication and prescriptions can prevent people from getting high on Percocet without medical reason.In fact, the Percocet high feeling can get you into lots of problems.
I think the formula of the perfume itself decides how fast it will spoil. My perfumes from Britney Spears Curious and Salvatore Ferragamo went bad within a year and a half. The Britney Spears one developed some precipitation and started smelling like alcohol, while the Salvatore Ferragamo just smelled plain weird.
A bad odor coming from nose is usually due to a foreign body, sinusitis, nasal polyp or even due to post nasal drip. Usually treating the cause takes care of the smell. You can try drinking plenty of fluids, using saline water for nasal irrigation, taking steam, and doing warm saline gargles.