Animal Anesthetic, Street Drug May Help Depression, Study Says
2006-08-07 16:43 (New York)
By Joi Preciphs
Aug. 7 (Bloomberg) -- A drug used legally to tranquilize
animals and illegally as a street hallucinogen called ``Special
K'' may give relief within hours to people whose depression
resists other treatments, a new study says.
About 70 percent of patients who got the drug, an animal
anesthetic called ketamine, had improved symptoms within a day
and 29 percent were symptom-free, according to a study to be
published today in the Archives of General Psychiatry. One in
three said the effects lasted at least a week.
``The public health implications of being able to treat
major depression this quickly would be enormous,'' said Elias A.
Zerhouni, head of the U.S. National Institutes of Health, in a
statement today.
Major depression affects more than 14 million Americans
yearly, according to the National Institute of Mental Health in
Bethesda, Maryland, which carried out the study. Patients who
are in the early stages of therapy for depression and those with
drug-resistant forms of the disorder are at high risk for
suicide or bodily harm.
In the study, researchers gave small doses of the fast
acting tranquilizer to an 18-patient study group that was
randomly assigned to receive either a dose of ketamine or an
inactive compound a week apart on two test days.
Patients experienced no ``serious adverse effects'' from
ketamine, the researchers said. ``Perceptual disturbances,''
euphoria, dizziness and increased sex drive were the most common
side effects, the study said. Most side effects stopped within
80 minutes after treatment, and none lasted beyond 110 minutes.
Delirium
When abused, ketamine is known to cause delirium, numbness,
loss of coordination, memory loss, depression and cognitive
problems, according to the U.S. National Institute on Drug Abuse
and the National Clearinghouse for Alcohol and Drug Information
Web sites. As little as 25 to 100 milligrams can cause
psychedelic effects and larger doses can cause vomiting and life
threatening convulsions.
Researchers in the depression study limited the doses used
for patients to 0.5 mg per kilogram of body weight. For example,
a 150-pound (68 kilogram) woman would have received about 34
milligrams of the drug.
Carlos Zarate, chief of the national institute's Mood
Disorders Unit, said the research team is exploring ways to
manipulate ketamine to lessen or completely eliminate the drug's
dangerous side-effects.
``The exciting thing is we now have evidence we can bring
about rapid antidepressant effects,'' Zarate said today in a
telephone interview, ``Now that we can do that very quickly, how
to do it consistently is a different story.''
Special K
Known on the street as Special K, Kat or Vitamin K,
recreational users take Ketamine for ``out-of-body'' experiences
similar to those caused by LSD and PCP use, according to the
U.S. Drug Enforcement Administration, which added ketamine to
its list of controlled substances seven years ago.
At the time, law-enforcement officials across the country
were reporting increased abuse of the drug at large-scale
parties frequented by teens and young adults, and in ``date
rape'' crimes, said Rusty Payne, a spokesman for the agency, in
a telephone interview today. More than 70 legitimate makers of
the drug are registered with the DEA, he said.
Past research in animals showed that ketamine blocks N-
methyl-D-aspartic acid, a protein that regulates glutamate, a
neurological chemical that affects electrical charges in the
brain. Dr. Zarate said past research paved the way for testing
anti-glutamatergic drugs that address neuro-degenerative
disorders such as Alzheimer's and Parkinson's Diseases.
Typical Patient
A typical patient with major depression reports at least
five or more symptoms for at least two weeks before a diagnosis
is made. Episodes usually are treated with medication,
psychotherapy or a combination of the two.
Modern depression drugs called SSRIs, which include Prozac,
Paxil, Zoloft and Effexor, and older classes of medicines called
tricyclic antidepressants, usually take weeks before patients'
symptoms improve. Sometimes, though, patients become unaffected
by the drugs over time.
--Editor: Gale.
Story illustration: For more medical-science news,
see {TNI MEDICAL SCIENCE <GO>}. For today's top health stories,
see {HTOP <GO>.}
To contact the reporter on this story:
Joi Preciphs in Washington at (1) (202) 624-1989 or
jpreciphs1@bloomberg.net.
2006-08-07 16:43 (New York)
By Joi Preciphs
Aug. 7 (Bloomberg) -- A drug used legally to tranquilize
animals and illegally as a street hallucinogen called ``Special
K'' may give relief within hours to people whose depression
resists other treatments, a new study says.
About 70 percent of patients who got the drug, an animal
anesthetic called ketamine, had improved symptoms within a day
and 29 percent were symptom-free, according to a study to be
published today in the Archives of General Psychiatry. One in
three said the effects lasted at least a week.
``The public health implications of being able to treat
major depression this quickly would be enormous,'' said Elias A.
Zerhouni, head of the U.S. National Institutes of Health, in a
statement today.
Major depression affects more than 14 million Americans
yearly, according to the National Institute of Mental Health in
Bethesda, Maryland, which carried out the study. Patients who
are in the early stages of therapy for depression and those with
drug-resistant forms of the disorder are at high risk for
suicide or bodily harm.
In the study, researchers gave small doses of the fast
acting tranquilizer to an 18-patient study group that was
randomly assigned to receive either a dose of ketamine or an
inactive compound a week apart on two test days.
Patients experienced no ``serious adverse effects'' from
ketamine, the researchers said. ``Perceptual disturbances,''
euphoria, dizziness and increased sex drive were the most common
side effects, the study said. Most side effects stopped within
80 minutes after treatment, and none lasted beyond 110 minutes.
Delirium
When abused, ketamine is known to cause delirium, numbness,
loss of coordination, memory loss, depression and cognitive
problems, according to the U.S. National Institute on Drug Abuse
and the National Clearinghouse for Alcohol and Drug Information
Web sites. As little as 25 to 100 milligrams can cause
psychedelic effects and larger doses can cause vomiting and life
threatening convulsions.
Researchers in the depression study limited the doses used
for patients to 0.5 mg per kilogram of body weight. For example,
a 150-pound (68 kilogram) woman would have received about 34
milligrams of the drug.
Carlos Zarate, chief of the national institute's Mood
Disorders Unit, said the research team is exploring ways to
manipulate ketamine to lessen or completely eliminate the drug's
dangerous side-effects.
``The exciting thing is we now have evidence we can bring
about rapid antidepressant effects,'' Zarate said today in a
telephone interview, ``Now that we can do that very quickly, how
to do it consistently is a different story.''
Special K
Known on the street as Special K, Kat or Vitamin K,
recreational users take Ketamine for ``out-of-body'' experiences
similar to those caused by LSD and PCP use, according to the
U.S. Drug Enforcement Administration, which added ketamine to
its list of controlled substances seven years ago.
At the time, law-enforcement officials across the country
were reporting increased abuse of the drug at large-scale
parties frequented by teens and young adults, and in ``date
rape'' crimes, said Rusty Payne, a spokesman for the agency, in
a telephone interview today. More than 70 legitimate makers of
the drug are registered with the DEA, he said.
Past research in animals showed that ketamine blocks N-
methyl-D-aspartic acid, a protein that regulates glutamate, a
neurological chemical that affects electrical charges in the
brain. Dr. Zarate said past research paved the way for testing
anti-glutamatergic drugs that address neuro-degenerative
disorders such as Alzheimer's and Parkinson's Diseases.
Typical Patient
A typical patient with major depression reports at least
five or more symptoms for at least two weeks before a diagnosis
is made. Episodes usually are treated with medication,
psychotherapy or a combination of the two.
Modern depression drugs called SSRIs, which include Prozac,
Paxil, Zoloft and Effexor, and older classes of medicines called
tricyclic antidepressants, usually take weeks before patients'
symptoms improve. Sometimes, though, patients become unaffected
by the drugs over time.
--Editor: Gale.
Story illustration: For more medical-science news,
see {TNI MEDICAL SCIENCE <GO>}. For today's top health stories,
see {HTOP <GO>.}
To contact the reporter on this story:
Joi Preciphs in Washington at (1) (202) 624-1989 or
jpreciphs1@bloomberg.net.
