The Health Service Executive (HSE) has confirmed a new drug to treat alcoholism will be made available through the medical card and drug payment schemes.

Selincro works by blocking the part of the brain which gives drinkers pleasure from alcohol, stopping them from wanting more than one drink.

Trials have shown it can cut consumption levels by two-thirds. It is not yet known when the drug will come on stream through the HSE.

Selincro, also known as Nalmefene, is the only licensed medicine which helps people reduce their drinking rather than aiding them to stop drinking altogether.

Severe alcoholics and those who are able to cut down without help would not be eligible for the drug. It is administered orally once a day and is taken when people feel the urge to drink.

In Britain, men qualify for the treatment if they consume 7.5 units of alcohol per day - around three to four pints of standard strength lager.

While it is offered to women in the UK who consume five units a day, which amounts to around half a bottle of wine.

It has been provided to patients in Scotland since October last year.

Chair of population health medicine at Trinity College Dublin is Professor Joe Barry.

He told the Pat Kenny Show here on Newstalk that around 150,000 people in Ireland are dependent on alcohol - and use of this drug will have to be carefully monitored.