"You shall not kindle any fire in any of your dwelling places on the Shabbat Day." (Shemot/Exodus 35:3)
Snorting coke on Shabbat is certainly no substitute for smoking, as neither are in the spirit of Shabbat.
If you cannot refrain from smoking or snorting, even on Shabbat, you may have a problem.
ShaBot says, "Kids, don't do drugs ... Especially on Shabbat!"
"The primary difference between Sefardi and Ashkenazi consonants is that the Sefardi pronunciation of the letter Taf without a vowel point is Taf, while the Ashkenazi pronunciation is Saf." (Artscroll transliteration)
But when reading the Shema, we must be careful not to soften hard consonants in this way, so Taf must be pronounced as Taf.