A £3 pill which is supposed to cut cravings for booze among binge drinkers may not actually work, researchers say. 

Nalmefene was introduced in Britain in 2014 as a drug to help curb the appetite for alcohol among problem drinkers.

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But a study published by the University of Stirling yesterday (Monday) said the research which led to the drug being prescribed in the UK was faulty. 

The study said only three trials were carried out by the drug's Danish manufacturers Lundbeck and the main focus of these trials shifted once the makers started to see different results. 

Many people also dropped out before the end of the process, the study found. 

Evidence of the pill's effectiveness was found to be weak, 

The study said the pill had a minimal effect on patients with people taking it found to only have one less drink per day on average. 

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The pill was also found to be more expensive than similar drugs and no comparison had been made with these alternatives during the trials. 

Dr Niamh Fitzgerald, a pharmacist and lecturer in alcohol studies at the University of Stirling, questioned why health watchdogs at NICE (the National Institute of Healthcare and Excellence) gave the go-ahead for the drug to be prescribed based on the evidence provided by the manufacturer. 

She said: "We found multiple problems with the way the trials for this drug were conducted. 

"We can't tell whether it's effective or not and we normally don't licence drugs unless we have really strong evidence that it is effective so that's what we're saying the evidence isn't yet strong enough 

"If the pharmaceutical company believe that it's effective then it should have continued and conducted further trials to prove that. 

"We require people to prove that the drugs are effective rather than just assume that they are based on unplanned analysis. 

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"We want to know how the system has failed in such a way that a drug with not good enough evidence has been licensed and has been recommended by NICE. 

"It's very hard to justify prescribing this drug over and above the comparator which is a generic drug which is much cheaper until such time that we can prove the drug is better than the comparator. 

"It raises questions as to how strong the regulatory system is and what other drugs are out there that may have gone through without the evidence being strong enough." 

Dr Fitzgerald is not the first to call into question the effectiveness the trials conducted into nalmefene, also known on the market as Selincro. 

In 2013, the one-a-day tablet was approved for use in Europe - but the German equivalent of NICE did not give approval for it having concluded it was inferior to similar pills. 

At the time of its decision in 2014, Professor Carole Longson of NICE said: "Alcohol dependence is a serious issue for many people. Nalmefene is clinically and cost effective." 

The drug is targeted at people who drink more than two glasses of wine a day or more than two pints of beer.

Dr Andrew Jones, medical director at Lundbeck Ltd said: "We are surprised by the conclusions of Fitzgerald and colleagues as described in the BBC article and strongly disagree.

"Robust scientific data is the reason for nalmefene being the first and only drug approved for the indication "reduction in alcohol consumption for alcohol dependent patients" and nalmefene has demonstrated a positive efficacy/safety profile for dependent drinkers.

"The European Medicines Agency (EMA) assessed the efficacy of nalmefene from three pivotal, randomized, double-blind, placebo controlled clinical trials including approximately 2,000 patients diagnosed with alcohol dependence who presented with a high drinking risk level.

"Patients enrolled in the studies drank on average 15 units per day (equivalent to approximately 1.5 bottles of wine).

"Patients treated with nalmefene combined with psychosocial intervention were able to reduce their alcohol consumption by more than 40 per cent within the first month, and by more than 60 per cent at six months.

"This corresponds to an average reduction equal to nearly one bottle of wine per day.

"The reduction of alcohol consumption in patients with high drinking risk levels was significantly greater in patients receiving nalmefene compared with patients receiving placebo at study end in all three studies and was considered clinically relevant.

"Data from the one-year study suggested continued efficacy of nalmefene beyond six months and up to one year of treatment.

"The patient criteria and endpoints in the clinical trials (heavy drinking days combined with total alcohol consumption) were required by the EMA and are internationally recognized by the WHO and professional advocacy groups.

"Moreover, nalmefene was assessed by the National Institute for Health and Clinical Excellence (NICE) and the Scottish Medicines Consortium (SMC), who both concluded that nalmefene is a cost-effective treatment for alcohol dependent patients and should be available for prescription in the NHS in England, Wales and Scotland."

A spokeswoman for the SMC yesterday (Mon) said they were "unable to comment" due to this being a "licensing issue".