It appears that members of the Orthodox Jewish community in Williamsburg, New York are using anal caffeine suppositories to deal with withdrawal from go juice:

Jews throughout Williamsburg snapped up caffeine suppositories today, hours before the start of the Yom Kippur fast that would deprive them of the jolt — and hunger suppression — that coffee typically provides.

The day-long fast is the centerpiece of the holiest day on the Jewish calendar — but some religious Jews see a Talmudic loophole that allows them to ingest their daily dose of caffeine, albeit through a different orifice.

“It helps — you know, it’s hard to concentrate when you’re fasting and also addicted to caffeine,” said Baruch Herzfeld, an Orthodox Jew who owns a bike store in Williamsburg. “Some take it before sundown, but most take it throughout their fasting. These guys love a good loophole.”

You know, tapering off over the few weeks before is both more in keeping with the spirit Halacha.^*

^*Jewish Law.