TIME: Almanac 1990/1990 Time Magazine Compact Almanac, The (1991)(Time).iso/time/121189/12118900.065

Text File | 1990-09-22 | 6KB | 96 lines

MEDICINE, Page 104

Can Drugs Cure Drug Addiction?

Researchers are developing new treatments to battle abuse

By Andrew Purvis


    When methadone was first introduced 24 years ago, it was hailed
as a magic bullet aimed at the heart of heroin addiction. A neat,
clean medical solution to a social problem. It has proved to be
something less than that. Methadone is a treatment, not a cure, for
addiction, and an imperfect one at that. But for some 100,000 of
the country's half-million heroin addicts, it offers an alternative
to shooting up as well as the possibility of a productive life.

    With the crack epidemic spiraling out of control and the
continuing threat of AIDS transmission through needle sharing, the
research community and government leaders are showing new interest
in medical approaches to drug addiction. After nearly a decade of
relative neglect under the "Just Say No" Reagan Administration, the
Federal Government has sharply increased funding to the National
Institute on Drug Abuse, which sponsors almost all of the world's
drug-abuse research. In the past year NIDA's medications and
basic-research budget jumped 50%, to $75 million, and Congress
promises similar increases in the future. "It's the Manhattan
Project for chemists in the war on drugs," declares Duncan Taylor,
a senior researcher at Bristol-Myers.

    The most promising of several drugs to combat addiction that
are being tested is buprenorphine, a pain reliever that in early
trials has shown clear advantages over methadone as a treatment for
heroin addiction. Under development by a team at Yale University,
the drug, like methadone, induces a generalized feeling of
contentment rather than heroin's precipitate rush and euphoria. It
is at least as effective as methadone in easing physical withdrawal
and reducing cravings, and it is significantly more potent in
blocking heroin's high if the addict tries to shoot up again.
Unlike methadone, buprenorphine is relatively nonaddictive and
carries almost no risk of overdose. In one trial of 41 addicts on
methadone maintenance, it cut the number of those who continued to
take heroin to just over half and eased 18 off opiates altogether.

    As a bonus, buprenorphine seems radically to suppress the urge
to take cocaine, which is abused by an estimated 70% to 80% of
heroin addicts. Methadone also tends to reduce coke use, but less
dramatically. While methadone may wean half of those treated from
cocaine, buprenorphine could slash the number of coke abusers to
almost nil, says Yale researcher Thomas Kosten. A Harvard study of
rhesus monkeys habituated to using coke found that daily doses of
buprenorphine led the monkeys to kick the habit completely.

    Other medications being used for psychiatric or neurological
conditions are also showing some promise. Flupenthixol, currently
prescribed overseas for schizophrenia, seems to soften the "crash,"
a unique combination of depression and craving that follows one
cocaine binge and typically leads to another round. In preliminary
trials on a group of ten Bahamian crack addicts seeking treatment,
researchers from Yale found that even low doses kept users off
cocaine for the two-month duration of the trial. Another drug,
carbamazepine, long taken to prevent seizures, has proved to be
moderately effective against cocaine craving. In tests this year,
six of 13 people taking the drug stopped using cocaine and the
remaining seven reduced their intake about two-thirds. Researchers
got the idea for using this antiseizure drug after hearing reports
that low doses of cocaine triggered mini-seizures in some animal
brains and that this "kindling" in the brain might be linked to
craving. By next year, NIDA expects to have eight to twelve
antiaddiction medications in clinical trials.

    Still, scientists are not expecting miracles, particularly in
battling cocaine addiction. Unlike heroin, which acts on the
pain-killing endorphin system alone, cocaine engages three separate
neurotransmitter systems: those based on dopamine, serotonin and
norepinephrine. Taken together, these networks govern the human
ability to experience pleasure, from watching a sunrise to having
sex. Blocking all these pleasure centers -- as methadone blocks the
heroin high -- would literally take the joy out of life, says
Yale's Kosten. "We'd turn out automatons." Addicts trying to quit
cocaine go through a stage called anhedonia, a sort of spiritless
limbo that typically drives the user to take the drug again. At
best, researchers can hope for a patchwork of drugs to block
discrete stages of cocaine withdrawal, such as craving and
depression.

    It is far from clear that the new drugs will succeed even in
this limited way. None have been tested in a full-scale trial
designed to mimic the conditions addicts encounter on the street.
Buprenorphine, which is one of the furthest along in testing, is
unlikely to receive approval before 1992. Scientists also readily
concede that medical therapy fails to address the underlying
psychological and social causes of drug abuse. Even if an addict
is weaned from one drug, they say, he will very often take up
another. A federal study released in August found that as many as
47% of patients at 15 methadone clinics across the country
continued to use heroin or other opiates, and up to 40% used
nonopiate drugs, usually cocaine. So scientists find themselves
aiming their magic bullet at a moving target. "We're constantly
having to treat new disease," said Marvin Snyder, director of
NIDA's medications-development program. "In five years, the problem
may not be cocaine, but some drug we haven't even heard of."