CANNABIS - THE PROS AND CONS - WHY WEED IS STILL A WORRY

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.

MEDICAL BENEFITS

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.

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: Cannabis oil.

THC - tetrahydrocannabinol (the active ingredient in cannabis).
Placebo - dummy treatment with no active ingredient. The trial is
investigating the effect of cannabis on muscle stiffness, spasm and
mobility for MS sufferers.

Psychological factors

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.

For further reading, Drugs Info File, by Dr Miriam Stoppard is
available from Mirror Direct on 0870 07 03 200, price UKP 5.99
including postage and packing.