Oct 16 2003
At one time, cannabis was thought to be a harmless recreational drug but increasingly evidence shows this isn't so, if it's used habitually.
However, the medical usefulness of cannabis is now well recognised and doctors are using it to treat pain and relieve muscle spasms in multiple sclerosis.
Miriam looks at latest findings in the big debate.
There is a downside to excessive use of cannabis. It stays in the body far longer than alcohol - around two months.
You may feel "sober" long before the effects have worn off but you shouldn't operate machinery or drive for four or five days after using it, as you're likely to have an accident in this state.
Cannabis is risky for people with breathing problems such as bronchitis and asthma. Two spliffs are the tar equivalent of six to 10 cigarettes.
A US study this week found that smoking the drug harms the quality and quantity of sperm produced.
As with smoking normal cigarettes and drinking alcohol, women who use cannabis risk harming their unborn babies.
Some long-term, heavy users may get panic attacks, exaggerated mood swings, feelings of persecution and suffer short-term memory loss.
It can trigger mental problems in people who may be predisposed to them, and depression in teenagers.
Cannabis and alcohol
IT'S a bad idea to smoke cannabis and drink alcohol. The combination will dry you out and make you very unsteady on your feet; it can even make you violent.
You're also more likely to feel sick or even be sick, especially if you haven't had cannabis before.
The hangover from the combination of cannabis and alcohol can be truly nightmarish.
Don't mix with other drugs
Mixing cannabis with ecstasy or speed is particularly bad because it can make you dangerously dehydrated. Nasty side effects from using cannabis with other drugs include hallucinations, being unable to move, having a heart attack and losing consciousness.
Can cannabis cause birth defects?
There's a strong link between smoking cannabis while pregnant and a baby having abnormalities, as well as stillbirth, miscarriage and early death of a baby.
If a pregnant woman smokes cannabis, the drug enters the baby's body through the placenta.
The baby feels the same effects as the mother, but to a much greater extent, and is much more easily harmed. So never use cannabis during pregnancy.
If you use cannabis you should give it up for at least three months before trying to conceive - and that means both of you.
Although cannabis has been used in medicine for 5,000 years, just over 30 years ago the drug was classified in Britain as having no medicinal value. Now the government backs cannabis medications.
1. As a painkiller tablet
Cannabis is being studied as a painkiller after surgery in a new NHS study.
If tests show no harmful side effects, cannabis could become a standard treatment.
There are 36 hospitals signed up to help find the 400 patients needed for the Medical Research Council project.
Post-operative patients will be given four pills after surgery, two of which will be different kinds of cannabis.
The remaining patients will be given either a standard drug or a placebo.
2. As a pain-relieving spray
Cannabis could be available in the UK by the end of this year as a pain-relieving spray.
Clinical trials already show how cannabis can relieve chronic pain for many people suffering from multiple sclerosis and nerve injuries.
Even cancer sufferers and those with rheumatoid arthritis and epilepsy may benefit.
Several clinics in Britain are testing cannabis sprays and results were recently submitted to the Medicines and Healthcare Products Regulatory Agency.
A two-year study into chronic pain shows brain receptors that regulate the nervous system respond to cannabis.
How does cannabis relieve pain?
When pain is perceived by the body, cannabis receptors damp down nerve activity and so numb pain.
Cannabis is sprayed in a controlled dose under the tongue, where it works quickly because it is absorbed straight into the bloodstream, taking effect within 30 minutes.
Researchers believe benefits of the spray are far more than simply relieving pain, as it also offers patients a greatly improved quality of life.
A person suffering from long-standing, constant pain every day has a miserable life - especially if they can't sleep properly.
The cannabis spray reduces pain at night and so helps give a decent night's sleep.
Fighting Multiple Sclerosis
In clinical trials, people with multiple sclerosis found cannabis spray extremely effective in relieving pain and muscle spasms.
The preparation needs approval from the Medicines Control Agency before it becomes generally available.
The largest study of cannabis treatment for MS is being co-ordinated from Plymouth. Patients are given one of the following:
A total of 150 patients with MS and painful muscle spasm are being studied to discover whether cannabis-based medicines have any psychological impact, any impact on mental processes, mood, pain and fatigue.
The three-year study is expected to end in February 2004.
Bladder dysfunction in advanced MS
Research with a small number of people with MS and severe bladder problems has taken place at the National Hospital for Neurology and Neurosurgery in London.
Preliminary results show cannabis-based medicine improves bladder function, lessening urinary frequency, and passing of urine at night.
This study, part funded by the MS Trust, has now ended and results are
yet to be published.
Copyright © 2003, Daily Mirror