On the AOL (UK) frontscreen, mention is made of a drug, which researchers claim may have potential in treating Alzheimer's Disease. The compound, PBT2, has shown promising results in mice. Patients in Sweden will now take part in a trial in humans, to see whether the drug is suitable for use in people. A more extensive trial will be started in 2007.
I tend to pour cold water on the expectations raised by this sort of promises. It is very early days. Alzheimer's Disease is an emotive subject, and I am reading at least one blog on AOL which describes the emotional pain suffered by those around a loved one who is struck down by the illness. Alzheimer's Disease is a progressive brain disorder, which is ultimately fatal. It cannot be cured; so far, the drugs used in its treatment have only served to delay further deterioration.
Before a drug can be prescribed by a doctor, it has to be proven to be "efficacious", i.e. do the job and not have side-effects disproportional to the condition being treated. This balance is best illustrated by the two extremes of the headache cure paracetamol and any chemotherapy agent for treating cancer. What happens if you don't take paracetamol? You have a headache, but it'll probably be gone the next day. What happens if you don't take the chemotherapy? You're likely to die a lot sooner than anticipated. Would you find it acceptable to be profoundly nauseated and sick, have your hair fall out and be susceptible to all sorts of infections just to cure a headache? No. Is this acceptable to tackle cancer, where the only alternative is death? I'd think so.
As noted above, new compounds are usually first tested on mice, guinea pigs and other animals. The number of laboratory animals has decreased hugely after efforts were made to find alternatives for live animals. If the drug is promising in animals then it is usually tested in volunteers and finally in groups of patients that the new medicine is likely to be used in. If anything untoward happens there, it's curtains. An extreme example was shown earlier in 2006, when six volunteers fell dangerously ill after being injected with a new compound. They required days and weeks of intensive care treatment and I'm not sure that they have all recovered.
Normally, a trial involves one group of patients receiving the new compound and another group receiving a blank (placebo) or the accepted norm of treatment, if "no treatment" is unacceptable. The patient nor the health professionals around him (doctors, nurses etc) know which one he is receiving. A trial can be halted if the new drug is working so well that withholding it from the other group would be unethical or if it is giving such catastrophic side-effects that it cannot be continued.
This is only one of several methods to try new medicines. After they have been marketed, the licensing agency asks the healthcare profession to report any untoward effects, in order that safety is kept at the highest possible level. Sometimes, this leads to a newly introduced drug being withdrawn from the market.
In the UK, the National Institute for Clinical Excellence NICE has to make recommendations to Health Authorities (England and Wales) or Health Boards (Scotland) as to the suitability of the new drug in treatment. This determines whether government will fund HA/HB to prescribe and supply the medicine. A sharp example was shown in the case of the breast cancer drug Herceptin recently. This was initially only licensed for use in the treatment of breast cancer which had not responded to first-line treatment. It was found to be effective in first line treatment, but is a heck of a lot more expensive than chemotherapy. Herceptin also only works in certain types of breast cancer. Campaigning by breast cancer support groups led to Herceptin being allowed for all stages of breast cancer.
It should be born in mind that funding for Herceptin may well have displaced funding for other, less high profile but equally devastating, illnesses which are just as costly.
The new Alzheimer's component is a few years away yet from introduction on the open market.
Any questions? Leave a comment.
Alzheimers, terrible disease. My dear Mother had it, along with cancer. She lived with me for 10 yrs before having o go to a Nrsg Home for the final 6 mos of her life. She had told me her Grandmother also had it, altho they didn't know what to call it back then. Her Mother died at an early age so we don't know if she would have gotten it. I wonder if I'll get it too? And my children?
ReplyDeleteBlessings, Sugar