Parkinson's drugs show promise in resistant TB

* Drugs could be used to fight dangerous forms of TB

* Compounds already proven in humans

By Julie Steenhuysen

CHICAGO, July 2 (Reuters) - Drugs used to treat Parkinson's disease show promise as a new way to stem the rise of drug-resistant forms of tuberculosis, U.S. researchers said on Thursday.

They said computer models and lab experiments suggest the drugs tolcapone or Tasmar made by Valeant Pharmaceuticals (VRX.N: Quote, Profile, Research), and entacapone or Comtan made by Novartis AG (NOVN.VX: Quote, Profile, Research) have the potential to treat multiple-drug-resistant and extensively drug-resistant strains of TB.

Computer programs predicted the chemically similar drugs should interfere with the TB bacillus, and tests in lab dishes using the drug Comtan confirmed it, the researchers said.

About 1.8 million people die worldwide each year from tuberculosis and a third of the world's population -- 2 billion people -- is infected, according to the World Health Organization.

Many people unknowingly have latent infections that can turn active if their immune system becomes weakened with other infections, such as HIV.

The WHO says that of 9 million new TB cases annually, about 490,000 are multiple-drug resistant TB or MDR-TB and about 40,000 are extensively drug resistant or XDR-TB.