IS THIS THE ANSWER FOR HOPELESS DOPEHEADS?

HAVING trouble giving up that nasty marijuana habit? A drug might soon
be available that stops you getting high when you smoke dope.

Marijuana's psychoactive effect is thought to come about when its key
ingredient, tetrahydrocannabinol or THC, binds to CB1 cannabinoid
receptors in the brain. A Paris-based company, Sanofi-Synthelabo, has
now developed a compound dubbed SR141716, which prevents chemicals
from binding to these CB1 sites. A recent study looked at the drug's
effect on appetite (New Scientist, 14 April, p 6), but Marilyn Huestis
and her colleagues at the National Institute on Drug Abuse In
Baltimore, Maryland, set out to see If it could stop people getting
high.

They found that a single dose of SR1417:16 could make regular
potsmokers feel about half as stoned as usual after smoking one joint.
The participants' heart rates also Increased only half as much as normal.

Whether marijuana is truly addictive is still being debated (New
Scientist, 21 October 2000, p 23). Huestis says there is evidence that
quitting marijuana Is a problem for some people. SR141716 might help,
she-says, but its effects after repeated doses will first have to be
explored. Her group is now doing just that.

Gerard Le Fur, executive vice-president of scientific affairs at
Sanofi-Synthelabo, says appetite suppression will still be the
company's main focus for SR141716, but so much the better If it could
also help people with drug problems. The blocker might eventually be
used to treat other disorders where CB1 receptors are suspected of
playing a role, such as memory loss, Huestis adds.

More at: Archives of General Psychiatry Not 38, p 322)