The Chinese State Food and Drug Administration (SFDA) advised patients to be cautious when using the drug Celebrex for treating osteoarthritis.

The warning follows the release of a study that shows the medicine might raise the risk of heart attacks.

The risk of heart trouble was 3.4 times greater for patients taking 400 milligrams of Celebrex twice daily than those using other medication such as amylum, the study, by US manufacturer Pfizer, reveals.

Celebrex was introduced to China in September 2000 for treatment of osteoarthritis at doses of 100 milligrams to 200 milligrams a day.

However, Pfizer revealed one trial of the study shows an increased cardiovascular risk over placebo, while another trial revealed no greater cardiovascular risk.

It said the risk study is on-going and has no plans to pull the painkiller off the market.

In China, the medicine is still available over the counter.

"Pfizer is taking immediate steps to fully understand the results and rapidly communicate new information to regulators, physicians and patients around the world," said Hank McKinnell, Pfizer chairman and chief executive officer.

The SFDA says that it will closely follow every step of the safety tests of the drug and has asked Pfizer to report the latest information of the evaluation.

"Although the medicine has not been included by any medical insurance systems and should be paid in full by patients in China, its use is popular," said Shi Zhencai, a doctor at the China-Japan Friendship Hospital.

"With a price of seven yuan (80 US cents) per tablet, the drug is quite effective in easing pain caused by arthrosis diseases," Shi said.

However, Shi said he has not treated any cases of heart attack from patients who have been taking the medicine for several years.

"Heart attacks might be caused by a long-term use and a big dose," Shi says.

He said he is now quite cautious and careful when recommending the medicine.

Shi's views were echoed by officials from SFDA who advised doctors to consider "alternative therapy" to Celebrex and take appropriate medical action.

Shi said two months ago Merck & Co recalled Vioxx, a similar arthritis drug, from the market as a study found it doubled the incidence of heart attack and stroke.

(China Daily December 22, 2004)