A common drug that helps in diabetes management might help people trying to quit nicotine block withdrawal symptoms, finds a study.

The study led by researchers from the Johns Hopkins University, showed that metformin potentially blocks symptoms of nicotine withdrawal in rodents. The team exposed laboratory mice to a two-week regimen of nicotine and found that they displayed no withdrawal symptoms when given the diabetes drugn.

Metaformin was also found to eliminate anxiety, irritability and other withdrawal symptoms in the rodents. "Metformin, because of its long-term record of safety and relative lack of side effects, has 'real potential' as a smoking cessation aid if clinical trials confirm the findings in mice," Sangwon Kim, from the varsity. Cigarette smoking is the leading cause of preventable illness and death.

Three medicines have been approved by the US Food and Drug Administration to help people break their addiction to nicotine, but smoking cessation rates remain low -- at about 15 per cent -- even though some studies say up to 70 per cent of smokers want to quit. Current therapies include nicotine replacement, an antidepressant and a medication aimed at reducing the cravings for and pleasurable effects of cigarettes, none of which directly treats nicotine withdrawal symptoms, Kim said.

For the new study, published week in Proceedings of the National Academy of Sciences, the team focussed on activating an enzyme known as AMP-activated protein kinase, or AMPK, which -- among other roles -- stimulates the breakdown of glucose for energy. The team discovered that the AMPK pathway is activated in mammals following chronic nicotine use, but is repressed during nicotine withdrawal. They set out to find whether AMPK, stimulated by metformin, could lessen or even eliminate the symptoms of nicotine withdrawal. They found that metformin completely prevented anxious behaviors caused by nicotine withdrawal at doses that had no effect on body weight, food consumption or glucose levels.