So let's talk a little about drug tolerance and physical
withdrawal, because there's huge misunderstanding of this issue.
Drug tolerance is the need of an increasing
dose of drug, to produce the same effect.
And it's universal amongst opioids. In fact,
with Remifentanil, which is this very short
acting drug, we can actually see
tolerance developing as we deliver
it, over a period of minutes to hours.
Tolerance is universal. You will get
tolerance to these drugs, I get tolerance to these
drugs if I take it. All patients on opioids
display physical withdrawal when they've been
on these drugs and develop tolerance,
when the drugs are discontinued. And that withdrawal
is associated usually with nausea,
sweating, sometimes anxiety, it tends
to be fairly short lived, and people
get over it and don't need further drugs.
But about 10% of individuals who develop
tolerance and are likely to show signs
of physical withdrawal, develop a craving
for the drug. And it's the craving that
defines addiction. It's the going out
of one's way, changing one's life,
losing family, losing jobs
in an effort to get more drug. That's the craving part.
And that's addiction. And it's extremely difficult
to deal with. It's the psychological
need for a drug that
has been discontinued. It's manifested by extreme
anxiety, drug seeking, self administration,
and purchase of street drugs or drugs
supplied by illegal methods. Withdrawal
of the drug is characterized by extreme anxiety,
sweating, rapid heart, vomiting, and respiratory rate,
a high respiratory rate, mental confusion or aggression,
because these individuals develop huge
tolerance to the drugs, they take huge doses.
Physical dependence on opioids is universal, and
is characterized by withdrawal. But addiction
and drug seeking are actually very uncommon
after surgery and after most traumas. Most patients
are glad to get off the opioids once they recover
from their pain, because they hate the side effects,
and they hate the cloudiness that their mind develops
while their on it. So the majority of people
are not at risk of developing