UPDATE 1-Pfizer's Lyrica gets expanded approval in Japan

* Lyrica approved in Japan for peripheral neuropathic pain

* Previously approved for postherpetic neuralgia

NEW YORK, Oct 28 (Reuters) - Japanese health regulators approved Pfizer Inc's PFE.N Lyrica to treat a type of nerve pain called peripheral neuropathic pain, Pfizer said on Thursday.

Japan is the world’s second largest market for prescription medicines after the United States.

Lyrica is the first medication approved in Japan for the chronic pain condition that includes symptoms such burning, tingling and shock-like sensations, Pfizer said.

The decision by Japanese health regulators follows Japanese approval in April of Lyrica for postherpetic neuralgia, a chronic pain condition that often follows a case of shingles.

“Neuropathic pain remains an under-diagnosed condition in many parts of the world, in large part due to low awareness and understanding of the condition and the fact that there are few proven treatment options available,” Steve Romano, head of medical affairs for Pfizer’s primary care business unit, said in a statement.

Peripheral neuropathic pain may be triggered by a variety of medical conditions, including nerve injury, sciatica, fibromyalgia, diabetes, shingles, cancer, HIV infection and HIV treatment, Pfizer said.

Lyrica, which had global sales of $762 million in the second quarter for the world's largest drugmaker, is co-promoted by Eisai Co Ltd 4523.T in Japan. (Reporting by Bill Berkrot; editing by Carol Bishopric)