NEW YORK (Reuters Life!) - Every year millions of Jews fast on their holiest day, Yom Kippur, and millions of Muslims fast for the month of Ramadan -- and every year, as many as 40 percent of those fasting develop serious headaches. But given the prohibitions against taking anything by mouth, there's little these observers can do until the fast ends - nightly for Muslims, and after 25 hours for Jews.
Now, a team of researchers in Israel, reporting in the journal Headache, think they have a solution -- a cousin of Vioxx (rofecoxib), the drug Merck pulled from the U.S. market in September 2004 because it increased the risks of heart attacks and other serious complications.
The drug, etoricoxib (Arcoxia), also made by Merck, is approved in several European countries, as well as Israel, but was refused FDA approval in the United States in 2007 because it works the same way Vioxx does.
Dr. Michael Drescher, of Hartford Hospital, Connecticut, and colleagues at two hospitals in Israel recruited more than 200 volunteers before Yom Kippur in October 2008.
Just before the holiday, half of them took etoricoxib, and half were given inactive placebo pills. Neither the volunteers nor the researchers knew which was which until after the study. Among the 195 study participants who responded to a survey after the holiday, about 36 percent who took etoricoxib developed headaches, compared to about 68 percent who took the placebo.
Those who took etoricoxib also had less severe headaches, and they had an easier time fasting.
Yom Kippur headache is a well documented phenomenon but the causes are unclear. Doctors have suspected withdrawal from caffeine, nicotine, oversleeping, and dehydration.
Drescher told Reuters Health that the fast doesn't allow people to start taking medicines but "there are different folk remedies, including suppositories, but really no good solution."
In fact, there is an entire book on how to treat medical conditions during Yom Kippur, noted Dr. Edward Reichman, an associate professor of emergency medicine at New York's Albert Einstein College of Medicine, and a rabbi and medical ethicist.
Because of the 25-hour fast, Drescher's team knew they needed a headache drug that wouldn't wear off quickly. Most painkillers only last 12 hours or less, but Yom Kippur headache usually kicks in at about 15 or 16 hours.
That led Drescher and a colleague to Vioxx, which has what scientists refer to as a long half-life - 17 hours - that means it acts longer.
Before their study, however, they asked "every credible rabbinical source" possible whether taking a drug to prevent headaches would be in the spirit of the fast. They said it was, to coin a phrase, kosher.
"Rabbis told us it's not a matter of suffering," Drescher said. "It's about divorcing yourself from the day to day."
When they did a study of Vioxx during Yom Kippur in September 2004, they saw similar results to those in the current report. But within days of that study, Merck withdrew the drug.
Then the researchers came upon etoricoxib, which Drescher said has an even longer half-life and good study results.
"It's a simple yet elegant study," Reichman told Reuters Health. "It's very well-done, and addresses a need in the community."
One of the paper's authors, Dr. Rafael Torgovicky, works for Merck Sharpe & Dohme Israel, a Merck unit that funded the study. Drescher has already applied for a grant for his next project -- figuring out whether etoricoxib will work for Ramadan headaches.
Editing by Belinda Goldsmith