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Treating opiate addiction, Part I:
Detoxification and maintenance
Dozens of opiates and related drugs (sometimes called opioids) have
been extracted from the seeds of the opium poppy or synthesized in
laboratories. The poppy seed contains morphine and codeine, among other
drugs. Synthetic derivatives include hydrocodone (Vicodin), oxycodone
(Percodan, OxyContin), hydromorphone (Dilaudid), and heroin (diacetylmorphine).
Some synthetic opiates or opioids with a different chemical structure
but similar effects on the body and brain are propoxyphene (Darvon),
meperidine (Demerol), and methadone. Physicians use many of these drugs
to treat pain.
Opiates suppress pain, reduce anxiety, and at sufficiently high doses
produce euphoria. Most can be taken by mouth, smoked, or snorted, although
addicts often prefer intravenous injection, which gives the strongest,
quickest pleasure. The use of intravenous needles can lead to infectious
disease, and an overdose, especially taken intravenously, often causes
respiratory arrest and death.
Addicts take more than they intend, repeatedly try to cut down or stop,
spend much time obtaining the drug and recovering from its effects, give
up other pursuits for the sake of the drug, and continue to use it despite
serious physical or psychological harm. Some cannot hold jobs and turn
to crime to pay for illegal drugs. Heroin has long been the favorite
of street addicts because it is several times more potent than morphine
and reaches the brain especially fast, producing a euphoric rush when
injected intravenously. But prescription opiate analgesics, especially
oxycodone and hydrocodone, have also become a problem.
In anyone who takes opiates regularly for a long time, nerve receptors
are likely to adapt and begin to resist the drug, causing the need for
higher doses. The other side of this tolerance is a physical withdrawal
reaction that occurs when the drug leaves the body and receptors must
readapt to its absence. This physical dependence is not equivalent to
addiction. Many patients who take an opiate for pain are physically dependent
but not addicted: The drug is not harming them, and they do not crave
it or go out of their way to obtain it.
Detoxification
For some addicts, the beginning of treatment is detoxification — controlled
and medically supervised withdrawal from the drug. (By itself, this is
not a solution, because most addicts will eventually resume taking the
drug unless they get further help.) The withdrawal symptoms — agitation;
anxiety; tremors; muscle aches; hot and cold flashes; sometimes nausea,
vomiting, and diarrhea — are not life-threatening, but are extremely
uncomfortable. The intensity of the reaction depends on the dose and
speed of withdrawal. Short-acting opiates, like heroin, tend to produce
more intense but briefer symptoms.
No single approach to detoxification is guaranteed to be best for all
addicts. Many heroin addicts are switched to the synthetic opiate methadone,
a longer-acting drug that can be taken orally or injected. Then the dose
is gradually reduced over a period of about a week. The anti-hypertensive
(blood pressure lowering) drug clonidine is sometimes added to shorten
the withdrawal time and relieve physical symptoms.
Methadone maintenance
Since the 1970s, professionals who care for opiate addicts have reluctantly
recognized that many of them will not or cannot stop taking the drug.
The solution is maintenance — dispensing opiates under medical
supervision. More than 100,000 American addicts are now using methadone
as a maintenance treatment. Although it is still politically controversial,
this practice has better scientific support than any other treatment
for any kind of drug or alcohol addiction.
Because there is a risk of diversion to the illicit market, addicts
must come to specialized clinics for methadone, which they take daily
in liquid form. A single dose lasts 24–36 hours, and there are
few side effects. Some methadone clinics also provide other medical and
social services.
Addicts who switch from illicit opiates to methadone avoid the highs
and lows and the medical risks of intravenous injection and the criminal
behavior that supports it. Studies show that they are less depressed,
more likely to hold a job and maintain a family life, less likely to
commit crimes, and less likely to contract HIV or hepatitis. Methadone
can be continued indefinitely, or the dose can be gradually reduced in
preparation for withdrawal. It has been estimated that about 25% of patients
eventually become abstinent, 25% continue to take the drug, and 50% go
on and off methadone repeatedly.
Buprenorphine
A promising approach to maintenance is the partial opioid agonist buprenorphine.
This drug is taken three times a week as a tablet held under the tongue.
It occupies opiate nerve receptors and produces a mild opiate-like effect.
At higher doses, it continues to produce the same weak effect while displacing
more potent drugs. In a person who is physically dependent on opiates,
buprenorphine causes a withdrawal reaction. There is some risk of abuse
if the tablet is dissolved and injected, so buprenorphine has been made
available in combination with the short-acting opiate antagonist naloxone,
which has little effect when absorbed under the tongue but neutralizes
the effect of injected opiates.
The main advantage of this combination, sold under the name Suboxone,
is that patients do not have to come to clinics to take it, because there
is no illicit market and no danger of diversion. Since 2002, individual
physicians with proper training and certification have been allowed to
prescribe buprenorphine in their offices for patients to take home.
April 2005 Update
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