US beer maker Fillmore Street Brewery is launching an extra strong version of its PJ Tight Pimp Juice energy drink brand.

PJ Tight Extra-Strength Pimp Juice contains 81mg of caffeine, which makes it much stronger than the regular offering, the brewer said.

"Most of our market research indicated that our customers loved the taste of the product but didn't believe they were experiencing the added boost," said Fillmore Street Brewery president William Wooten. "We decided to heed their call for caffeine, make one of the strongest energy drinks in the industry, and still maintain the sweet, smooth taste of the original."

Launched in 2003, Pimp Juice is the number one selling hip hop energy drink worldwide, Fillmore Street claims.

The brewer has also announced that it has signed a distribution agreement with Amazon.com which will see Pimp Juice sold through the online retailer. Pimp Juice has also linked up with the software publisher and distributor Navarre Corporation.

The company also announced that it has expanded distribution for Pimp Juice in Eastern Europe and has signed a licensing deal to produce the brand in Germany.