Alcohol addicts are being refused a drug because doctors have unfounded fears it is dangerous, experts have found.
Naltexone is not being given to up to 99 per cent of people who need it over fears it is toxic to the liver, researchers warn.
But there has been no evidence to support such claims, according to the ever first systematic review of its kind.
This could have ‘devastating consequences’, academics said, because dishing out the drug could reduce deaths among alcoholics.
Alcohol addicts are being refused a drug, naltexone, as doctors have unfounded fears it is toxic, experts at the University of Manchester found in a systematic review
There were 7,697 alcohol-specific deaths in the UK in 2017, or 12.2 deaths per 100,000 population, according to official figures.
The review of 89 clinical trials of naltrexone by the team at the University of Manchester was based on 11,194 participants.
The results were published in BMC Medicine.
It found no evidence of any serious side effects linked to naltrexone, which, when used, works alongside supportive therapy.
The only risk is if a person is also taking painkilling opiates, the researchers, led by Dr Monica Bolton, said.
Dr Bolton, who conducted the research as part of her Master’s degree said: ‘Though naltrexone is licensed for the treatment of alcohol addiction, it remains under-utilized.
‘And that has devastating consequences for individuals, health and social services in the UK and around the world.
‘As far as we know there is only one contraindication: painkilling opiates, such as codeine. These should not be taken with naltrexone, as it works by blocking opiates in the brain.
‘Up to 58 per cent of alcohol-dependent people in England want to reduce their drinking, and this drug could help them succeed.
‘It is cost effective and could reduce deaths.’
Until 2013, naltrexone carried a warning from the FDA for a rare side effect of liver toxicity when given in high doses, which initially came from several studies in the 1980s.
Patients in the studies, sometimes non-alcoholics, received up to 300mg of naltrexone. However, in treatment, it is used at widely varying doses from three to 250mg.
Due to reports, doctors have been reluctant to give naltrexone, according to the team.
There are four drugs used to treat alcohol dependence in the UK, including naltrexone.
Dr Alex Hodkinson, from the University of Manchester, said: ‘Previous research shows that naltrexone is prescribed to less than 0.5 per cent of those eligible.
‘And only 11.7 per cent of those diagnosed with more severe forms of alcohol dependence received relevant drug therapy in the 12 months following diagnosis.
‘Like all drugs for alcohol addiction, the chaotic nature of being an addict means this drug is simply not prescribed as much as it should be.
‘It’s also a cultural issue: there is a reluctance to prescribe one drug to combat addiction in another substance.
‘Our review also shows that fears over side-effects are unfounded.’
But Ian Hamilton, a lecturer in mental health and addiction at the University of York, told MailOnline: ‘I’m not surprised so few doctors prescribe it for people with alcohol dependency as these people are likely to have compromised liver functioning, so anything that might even be a small risk to the liver would be viewed as potentially dangerous.
‘I think naltrexone offers some promise in treatment of alcohol dependency but we need some long term follow up studies to better understand the risks and drawbacks.’
Known side effects include nausea, vomiting, abdominal pain, decreased appetite, dizziness, lethargy, headaches and sleep disorders.
Naltrexone is being investigated for a range of other conditions such as other addictions, gambling and other impulse control disorders.
Anecdotal evidence also suggests that at a very low dose, it may also be able to treat Crohn’s disease, HIV, multiple sclerosis, fibromyalgia and Chronic Fatigue Syndrome (ME/CFS).
In the UK, around 1,400 NHS prescriptions for low-dose naltrexone are issued per year while over 12,000 people have received a private prescription in the last ten years.
However, Dr Bolton argues that more research is needed to understand if the drug is effective for these conditions, and what happens over prolonged periods of time.
She said: ‘As it is safe, cheap and long out of patent, naltrexone would seem an excellent candidate for repurposing for a whole range of conditions.’