Like many Yom Kippur observers, Michael Drescher would suffer headaches caused by the holiday's 25-hour fast.

Popping an aspirin wasn't an option, since that would break the spirit of the fast. But Drescher, a physician with Hartford Hospital, has found a kosher solution. In time for Yom Kippur today, the results of his study were published this week in Headache: The Journal of Head and Face Pain. Unfortunately for U.S. observers, the FDA hasn't signed off on it.

Fasting traditionally begins on Yom Kippur at sundown and lasts until the next day, one hour after sundown. Why fasting causes headaches is unknown, but researchers believe possible causes include dehydration and withdrawal from caffeine.

"If you fast for 25 hours, it's not uncommon for people to suffer," Drescher says, adding that headaches often set in around the 16th hour.

Drescher, who divides his time between Connecticut and Israel, has been trying to find a solution for a while. A few years ago, he studied the use of the drug Vioxx for treating Yom Kippur headache (the term has been used in medical journal articles). Because the medicine's effects last for more than 25 hours, observers can take a dose before the fast begins.

It worked "extremely well" on subjects, he says, but the drug was taken off the market shortly after that due to its cadiovascular effects. So he tried again, this time with the drug Etoricoxib, a close relation to Vioxx. It also worked well: Those who took it had fewer and milder headaches than those who took placebos.

The subjects, he says, told him that they had "a more spritual experience, because they weren't suffering." He has consulted rabbis about using the medication and has been told that it doesn't break the spirit of the fasting.

The downside is that Etoricoxib isn't available in the United States. But Yom Kippur observers in Canada, Europe and Israel can fast pain-free, as the drug is avalable in their parts of the world. Drescher mentions that Celebrex, available in the United States, is similar to Etoricoxib, but he stops short of recommending it, since he hasn't done any formal studies on it.