Cadence, the San Diego, CA-based pharmaceutical firm said today the US Food and Drug Administration has given green light to the company’s intravenous formulation of the popular pain-killer acetaminophen, the same active ingredient found in Tylenol.

This pain relief and fever reduction therapy has been available by prescription for years in Europe, where Bristol-Myers Squibb markets the product with brand name Perfalgan. Approximately 90 million vials of IV  acetaminophen were sold in Europe in 2008. Cadence acquired the exclusive rights to  OFIRMEV in the United States and Canada in 2006 from  Bristol-Myers Squibb.

The company said they will begin selling their version of the drug, branded as Ofirmev, in the first quarter of 2011.

“IV acetaminophen is the unit market share leader among all injectable pain medications in Europe,” said Ted Schroeder, president and chief executive officer of Cadence. “We believe that Ofirmev will fill a significant gap in the United States for the treatment of pain and fever in the hospital setting.”

Ofirmev will be used as an alternative to opium-based pain killers such as morphine and as a compliment to smaller doses of those more traditional treatments.

The new therapy was approved for adults and children over 2 years old. Like the pill version, Ofirmev shouldn’t be given to patients with liver disease because of a risk of further damaging the organ.

In February this year, FDA postponed its final review of Ofirmev after regulators observed “deficiencies” during an inspection of a contractor’s manufacturing plant.

As a condition of approval, the FDA is requiring Cadence to conduct a post-market study of Ofirmev in infants and new-born babies to determine if the IV drug works in them.