April 1 (Reuters) - The U.S. Food and Drug Administration is relaxing its restrictions on the use of over-the-counter nicotine patches, gum and lozenges. Currently, consumers are instructed to stop smoking when they begin using a nicotine replacement product and to stop using it after 12 weeks. The FDA said on Monday it plans to remove both these restrictions in response to claims by critics that they may cause some smokers to abandon attempts to quit if they have a cigarette while on a replacement therapy. Allowing people to stay on a nicotine replacement for longer than 12 weeks may increase their chance of quitting, they say. British drugmaker GlaxoSmithKline Plc, whose nicotine replacement products include Nicorette chewing gum and the NicoDerm skin patch, commended the decision, saying it believes "this is a positive step to help more smokers quit." The FDA said nicotine patches and gum were first approved between 1984 and 1992, while nicotine lozenges and mini-lozenges were approved between 2002 and 2009. After reviewing published literature, the agency said, it has determined that the concomitant use of cigarettes and other nicotine-containing products "does not raise significant safety concerns."