11 June 2004
Dr Alasdair Coles
Multiple Sclerosis Society
The use of low-dose naltrexone (LDN) as a treatment for multiple sclerosis has been widely publicised on the internet and is now attracting the attention of other media.
There has been no clinical trial of LDN in MS. So what do we know about it?
Naltrexone is licensed in the UK to help treat people who are addicted to opiates, such as heroin. It does this by blocking their actions in the brain and making the drugs less pleasurable. It is only prescribed in specialised clinics and is given in doses of 50 to 150mg a day for three days a week. There have been several hundred trials of naltrexone in various other forms of addiction including alcohol, cocaine and gambling. Advocates of its use in MS suggest it should be given at a much lower dose of 3 to 4.5 mg daily, hence the term low-dose naltrexone.
Why should naltrexone work in MS?
In laboratory experiments, naltrexone increases the proliferation of immune cells. In people with AIDS, naltrexone may help standard antiretroviral drugs boost the function of the immune system. Advocates say that this would be a good thing in multiple sclerosis. However, many neurologists disagree. The standard approach to the treatment of MS is to suppress the immune system because the disease is believed to be due to excessive and inappropriate immune activity.
Current use of LDN in MS
Some people with MS in the UK may have been prescribed LDN by their own GPs. Between 300 and 400 people with MS have bought the drug from a retired GP in Wales. But no-one is collecting information on its possible benefits and side-effects. A neurologist in Dublin has used LDN in a few people with MS and found it ineffective. However, the drug’s advocates say that the wrong formulation of LDN was used.
The retired GP does not see the patients to whom he prescribes and sells the drug. He does not record any of their medical details or seek confirmation that people asking for LDN have MS. Nor does he consult with their GP or neurologist. This falls short of the normal standards for prescribing a drug in this country, where most people would expect to see the prescribing doctor and trust there was liaison between the various doctors involved in their care. Attempts to rectify these shortcomings are currently taking place.
Naltrexone and beta interferon
Advocates of LDN suggest that it does not work when taken in conjunction with beta interferon. There is no scientific basis for this. It is very unwise to give up an approved licensed treatment, which is of proven value in MS and has been used by tens of thousands of people with the disease, in favour of a drug, which has been used by a few hundred people and for which there is no evidence of benefit.
Should there be a trial of LDN in MS?
There are some striking stories about the beneficial effects of LDN for a few people with multiple sclerosis. Unfortunately, experience has repeatedly shown anecdotal evidence to be an unreliable way of gauging the true effect of a new drug in MS. The best test for LDN would be a clinical trial. However, we understand the drug’s manufacturers are not prepared to undertake one, and few neurologists would wish to conduct a trial of a drug, which boosts the immune system, when immue cells are already overactive. An alternative would be for the advocates of LDN to set up a study and resource it. There are many bodies in the UK to which people can apply for funds for clinical trials, including the MS Society. The Society would be happy to advise on drafting a grant application.
Copyright © 2004, Multiple Sclerosis Society