There is no known early copy of "The Unfortuate Rake". The tune is known from a collection of Irish tunes published by Smollet Holden, c 1805, and it's in 'Crosby's Irish Musical Repository' 1808 (copy on my website).

The earliest copy of the song now known is "The Buck's Elegy", c 1800, and the pills are in it in the line "I'd took pila cotia, all sorts of white mercury."