The United States Food and Drug Administration has published a warning  about Propofol, a short-acting intravenous anesthetic agent - that Teva Pharmaceuticals (TASE, Nasdaq: TEVA) markets mainly to clinics and hospitals.

The watchdog warned about a group of patients who had experienced chills, fever and aches immediately after receiving a shot of Propofol as a local or general anesthetic.

The FDA said it had examined the ampoules of the drug used on the patients who suffered the side effects. But the tests found no evidence of bacterial infestation or toxins, the agency said.

It recommended that doctors follow the current storage and usage directions carefully and report any unusual symptoms.

Any patient who feels chills, fever or pain after receiving Propofol should be tested for bacterial infection of the blood, which can lead to death mainly among the elderly and weak, or people with compromised immune systems.

Propofol, which is marketed as Diprivan and in generic versions, is responsible for 28% of the annual sales of Sicor, which Teva bought in November 2003 for $3.4 billion.