Wyeth has finally won federal regulatory approval to sell Tygacil. The antibiotic is said to have the ability to fight infections that can't be cured with the treatment with existing medications.

Wyeth says Tygacil cures a wide variety of potentially fatal infections, including those caused by E. coli bacteria. The company also claims Tygacil is indispensable in treating skin infections, ulcers, burns and abscesses.

Some analysts believe Tygacil will redefine the way the doctors treat intensive-care patients. The antibiotic is expected to produce $400 million in worldwide sales by 2010.

The drug belongs to a new class of medicines called glycylcyclines. The Food and Drug Administration is approving this type medication for the first time.

The antibiotic is being evaluated in Europe, Canada, Mexico and Taiwan.