Transcript Addictive Medication

Addictive Medication
David Cook
University of Alberta
The agenda this afternoon
1:45pm-2:30pm
2:30pm-2:45pm
2:45pm-3:30pm
3:30pm-3:45pm
3:45pm-4:10pm
4:10pm-4:30pm
Introduction to addiction, Opioids
Break
Benzodiazepines
Break
Methylphenidate etc
Questions
Some definitions
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Drug use – taking something
Drug abuse – taking something that
results in negative consequences
Drug addiction – continued drug use
where it is blindingly obvious that drug
use is causing problems with work, home,
family life, friendships, spirituality etc.
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Abstinence syndrome (Withdrawal syndrome,
previously called “physical dependence”)
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A situation in which the body has changed so that it
behaves more normally in the presence of the drug
than its absence. That is – deprive the person of
the drug and they get sick.
Tolerance
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A situation where the user needs progressively
more of the drug to get the same effect
There are reward pathways in the brain
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Stimulation of those nerves makes us feel good
The pathway exists to reward us for actions that
are good for the individual or the species (eating,
sex etc.)
When we feel good we want to repeat the
experience
We easily become dependent on behaviours that
stimulate this pathway (gambling, music etc.)
The drugs simply activate the reward pathway!
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GABA (Alcohol, Benzodiazepines etc.)
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Opiods (Heroin etc.)
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Dopamine (Amphetamines and Cocaine)
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Acetylcholine (Nicotine)
The drugs work at the most fundamental
survival level
Consequences of repeated drug use are:
The pathway starts to turn itself off!
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Increased dose to obtain the same effect
Reduction or absence in the effect of “normal” reward
stimuli
After abstention NOTHING activates the pathway!
After abstention there will be an abnormal emphasis
on getting the reward pathway working
Key point about brain chemistry
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Attempts to abstain from drugs are
difficult because the user has rewired
the brain. Expecting the user to be
able to stop drug use and immediately
regain normal attitudes is unrealistic.
The healing process is real and may
be prolonged.
Narcotics, Opiates, Opioids,
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Narcotics is an old term for these drugs, often
used for legal purposes
Opiates are compounds that are chemically
related to morphine
Opioids are ANY compounds that interact with
the opioid receptor
Opium poppy
Photo: Opium.Org
Photo: CIA
Scraping off the resin
Photo: CIA
Opium gum
Photo: CIA
Heroin
Photo: CIA
Where does it come from?
Opium/Morphine/Heroin
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These are by far the best pain relieving drugs
we have!
They have been known for more than 3000
years as agents that relieve pain, cough and
diarrhoea
Addiction to the drugs has been known for
almost as long as the pain relieving properties
have been known
Pain
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What causes it
How the body
responds to it
How we control it
Sir William Osler
“The greatest service
a physician can render
to his patients is in the
alleviation of pain”
Pain has two components: 1
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The pain itself which results from
nerves near the site of the pain
transmitting information.
“Brain? This is your big toe. You just
stubbed me, you idiot!”
There is a threshold…
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Not all perceived touch is painful
Not all warmth is experienced as a burn
Injury releases prostaglandins - chemicals that
AMPLIFY the pain sensation
If we block the production of prostaglandins, the
pain will recede to levels that are not
experienced as pain.
This is how Aspirin® and Tylenol® work
The second part is how the pain is
interpreted. This is MUCH more
complicated!
It hurts!
It hurts – but its worth it!
It hurts but it is a profound religious
experience
It hurts but it turns me on!
Pain is sensed by nerve endings…
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Two sorts of pain fibres that carry messages
to the central nervous sytem:
Aδ fibres – very fast and trigger the reflex that
makes us move away from the pain in less
than 0.5 sec!
C fibres are slower but convey “it HURTS”
takes about 2 seconds
Pain hits us twice!
Neuropathic pain arises from nerve damage
The fibres do NOT go straight to
the brain
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They go to a part of the spinal cord that is called
the “Dorsal horn” via the dorsal root ganglia.
The dorsal horn
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Organizes the reflex motor response
Transmits the message to the brain that something
painful has happened via the ASCENDING
PATHWAYS
Face and neck nerves go to the brainstem
The dorsal horn can get
confused…
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The structure gets multiple inputs from different
sites. Usually it can sort them out, but
sometimes it makes a mistake.
Referred pain
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chronic pain
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How is the information sent
onwards?
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There are lots of chemical messengers in the
dorsal horn. Opioid receptors block the
transmission of information.
Thus drugs like codeine, morphine and
Demerol® have a direct pain-relieving effect
This is just part of the story…
The brain can modulate the pain
sensation
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The brain sends DESCENDING nerves to the
dorsal horn.
These nerves are only stimulated by very unusual
situations, BUT if they are stimulated, they block
the upward transmission of information.
Opioid receptors are key
This is another way in which codeine etc work.
How does the brain convert the
information into “pain”
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We really don’t know!
The drugs themselves
High-potency, short acting
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Fentanyl (Sublimaze®), Sufentanyl (Sufenta®), Alfentanyl
(Alfenta®), Oxymorphone (Numorphan®)
Analgesics
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Morphine (MS-Contin®), Heroin, Meperidine (Demerol®),
butorphanol (Stadol®), hydromorphone (Dilaudid®),
Nalbuphine (Nubain®)
Orally active
 Codeine, Oxycodone (Oxycontin®, Percodan®,
Percocet®)
All agents except codeine require a triplicate
prescription
Tylenol-3®, 292® etc.
Percocet®, Percodan®, Oxycontin®
Tylenol-3®, 292® etc.
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Why? Peaceful pleasant mild heroin-like. Often
arises from prescription
Acute risks? Minimal, although combination with
other drugs may cause problems
Long term risks? Significant dependence that is
difficult to shake. Constipation, difficulty in
providing good pain management
Real risks? Dependence
Opioid withdrawal
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Painful but not life-threatening
Craving, Restlessness, increased pain
sensitivity, nausea, cramps, muscle aches,
sleeplessness, anxiety
Pupillary dilation, sweating, hair stands on end
(“cold turkey”), increased heart rate, diarrhoea,
fever
Triggered by antagonists
Issues around opioid use
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In-patient use is almost never responsible for addiction
Outpatient use is a different story – there are lots of
excuses for long-term use
Things that are probably not helped a great deal
include:
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Fibromyalgia
Low back pain
Headache
BUT there are a few conditions in which long-term
opioid use may be the best option
Break time!
Anxiety and insomnia
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Anxiety is a useful thing, but may sometimes
became disabling.
On the basis of the effects of drugs, presumably
there are problems involving the GABA receptor
system, but we are not really sure
For most people the management of long-term
disabling anxiety involves psychotherapy
Drug use is usually a short-term solution only
Sleep
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We know a lot about sleep, but we still do not
know how it works and why we need it
Generally the body takes what sleep it needs
A cycle starts in which something causes an
interruption of normal sleep and this is followed
by worry about sleep followed by further
insomnia. A pattern of chronic arousal results.
Medication produces sleep, but it is not a
normal sleep
Non-drug management of sleep disorder
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Make sure that it it really is happening – most
insomniacs underestimate the time spent asleep
Caffeine – no caffeinated beverages after 2:00pm
Exercise
Warm drink (not caffeinated!)
Acceptance of changed sleep pattern
Relaxation exercises
Do not use bedroom for reading, TV etc
Develop a routine
Sedative-hypnotic drugs
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Benzodiazepines:Valium®, Librium®, Ativan®,
Serax®, Xanax®, Lectopam®, Versed®,
Tranxene®, Dalmane®, Mogadon®, Restoril®,
Halcion®
Others: Imovane®, Equanil®, 282 MEPs®
All these drugs have the potential to cause
addiction
ALL SEDATIVE/HYPNOTICS
All work at the
GABA
receptor and
all create the
following
series of
events:
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Decreased anxiety
Excitement/Disinhibition
Sedation
Sleep
Anesthesia
Coma
Respiratory depression
Death
ALL these drugs
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Produce rebound insomnia
Produce somnolence, impair driving and in overdose
depress breathing.
Interact with alcohol and with each other to produce
effects which are greater.
Can impair memory, particularly in the elderly
Are relatively free of damage to heart, liver, blood
pressure etc.
Make it easier to survive anxiety and stress, at the cost
of making everything bland.
Medically should only be used for longer than one
month in rare cases.
Other uses
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Sedation prior to surgery (no risk of addiction!)
Sedation in the ER after stimulant overdose
Clonazepam (Klonopin®) is used in epilepsy and
sometimes in mania – all the benzodiazepines
have some anti-seizure activity
Chlordiazepoxide (Librium®) is used to
suppress withdrawal syndrome in alcoholics
As muscle relaxants
Issues around benzodiazepine use
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The drugs are over-used, particularly in the long
term management of anxiety
They are sometimes used because the doctor
feels a need to do something to alleviate the
patient's distress; the patient may be better off
to change their circumstances
Withdrawal is difficult – use a physician,
because seizures can occur
The drugs do have a street value
You deserve a
break!
Stimulants - ADHD
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The drugs are methylphenidate (Ritalin®,
Concerta®, Attendade, which is optically pure dmethylphenidate), amphetamines (Dexedrine,
Adderal®, not available in Canada since Feb
2005).
They are used for:
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ADHD
Narcolepsy
All have a street value
ADHD
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Incidence is 3-5% in children. In about 80% of
thes, problems continue into the teens, and
about half have problems into adulthood.
If one plots activity vs number of children:
ADHD
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Poor attention span
Opposition-defiance disorder
Conduct disorder
Often “diagnosed” by teachers
Often over-diagnosed
A child psychiatrist can make sensible
decisions
Resistance to authority is not, by itself a sign of
ADHD
ADHD
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The cause is largely unknown
There are significant differences in the brains of
kids with ADHD
Treatment tends to normalize the brain picture
About 95% of ADHD patients improve with
medication
There are strong opinions on the value of
medication, often held by people with no
experience of the condition and no knowledge
of the literature.
What do stimulants do?
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The help the patient to concentrate
They improve tolerance for boredom and
increase the chances of finishing a task
They do not help learning as such
They improve relationships between the patient
and his/her teacher, parents and peers
The medicine is usually well-tolerated
Medication
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Complementary and alternative therapies have
usually not been subjected to appropriate
testing.
Behavioural therapy along with medication
seems to give the best results, followed closely
by medication alone. Behavioural or community
psychotherapy or guidance are less successful.
That said, there are plenty of things parents and
others can do to help the child.
Adverse effects
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Reduced appetite during the day, but no evidence
of long-term growth retardation
Difficulty falling asleep (often resolved by using a
lower dose)
VERY RARE cardiovascular problems, but the
drugs do elevate blood pressure and heart rate.
Addiction rates in treated patients are lower than in
untreated controls
In one study 25% of those receiving the drugs had
diverted the material onto the street, at least once
Addiction
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True addiction in people using the drugs for
ADHD is very rare
If the drugs are taken recreationally by someone
who does not have ADHD, they have effects like
amphetamines
Ritalin® used to be combined with the opioid
pentazocine (Talwin®) to give “Ts & Rs” or
“Poor man’s heroin”. Talwin is no longer widely
available in an injectable form, but we still see
this combination on occasion
Client issues around ADHD
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Make sure that the patient really does have ADHD
Support the use of stimulants if the child does
have ADHD
Make sure the drug is not being diverted
Key concepts in support of the patient include
emotional support and praise, clear statements of
the child’s responsibility, and the establishment of
routine.
Good nutrition and healthy sleep patterns are
important
Time for your questions on
anything we have discussed!
Thanks, and bon voyage!