Ming-Chih Kao, PhD, MD on Medications & Back Pain

By Paul Henry / in , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , /

Earned his doctoral degree
in computational biology and biostatistics at
Harvard University. After graduate school, he
continued to research at NIH and earned an MD at the
University of Michigan. He has an unusual
experience as a primary care physician in San Francisco. There, the complexities of
chronic pain, its diagnosis, and its management
led him to pursue a career in pain medicine. And we’re very fortunate
to have him in the clinic. He believes the best
approach to chronic pain is both scientific
and patient-centric. And I would just like to
add he is an Assistant Professor at Stanford and he is
the Associate Chief of Clinic Operations at the Stanford
Pain Management Center. And it looks like
you’ve got your talk up. So please join me in
welcoming Dr. Kao. [APPLAUSE] We don’t have it on this side. I don’t have it on– OK. [INAUDIBLE] Which one does the– Over here– Which one does the– –it might be this one. –screen extension? Might be this one. You have five–
then, which one– the projector is
[INAUDIBLE] these. Two switches [INAUDIBLE]. [SIDE CONVERSATION] A brain tumor,
Parkinson’s, epilepsy– they can impair
the nervous system and disable normal function. But, here at Stanford,
our neuro-specialists are finding ways to address the
damage and restore activity. Through innovative techniques,
like rerouting circuits in the brain, we
can often recover function that once was lost. For a patient, it’s
like a miracle. For us, another door opens. Discover more at
stanfordhealthcare.org. OK. Well, thank you. Sorry about that. That was a little technical
issue with PowerPoint. I felt strongly about
using my own laptop because I spend a
couple of nights working on a very cool movie
I’m going to show you later. So I’m very proud of it. So I’d like to take this
opportunity to talk about the role– the proper
role, perhaps– of medications in
chronic low back pain. Now as Dr. Darnall
had mentioned, I used to work as a primary
care physician in San Francisco. And now I’m a full-time
clinician at a Stanford Pain Management Center. And I see a lot of patients
with chronic low back pain. I have strong feelings about it. I’m very passionate
about helping patients with chronic low back pain. I’d like to share some
thoughts with you today. First of all, no disclosures. So as far as chronic low
back pain and medication use in this
condition, today, I’m going to start by
talking about a problem. I think we as a society– not us, not you, but we
as a society together– have found ourselves
in trouble when it comes to medication
use in lower back pain. I’ll describe why that is,
and I’ll offer a solution. In fact, it’s a solution that
should not be surprising to you because you have heard it,
starting from this morning, all of our pain specialists. And I will come back and
talk about those solutions. And, finally, I’m
going to turn around in sort of the insider’s view
on chronic low back pain– take the perspective
of patients and offer some tips of medications in
the chronic low back pain. All right. So this is what I think of
when I think about medication use in chronic low back pain. On a society level,
this is a big sinkhole. And I think we,
together as a society, have found ourselves in trouble. And this is the kind of hole
where we find ourselves in. And for the next
10 minutes or so, I’d like to describe
why I think this way. And I will offer a
solution at the end. So as Dr. Mackey had
said this morning, chronic low back pain is
the most common chronic pain condition in the United States. The 28% figure that Dr. Mackey
has cited is replicated here. This came from a nationally
representative survey performed by the CDC. And it found that, among
adults 18 years or older– civilian, non-institutionalized
population– about 28% of them reported chronic low back pain
lasting more than three months. Now 28% is just a number. Exactly how big is that? So if we asked all the patients
with chronic low back pain to most westward– to
move towards California– a couple of things would happen. First, our housing prices
would get even more amazing. And, second of all, it’s
going to fill– overfill– California. As for the required,
28% of the US population is going to fill California,
Oregon, Washington, Arizona, Nevada, and New Mexico. That’s 66 million– that’s
28% of the United States population. And that is a
significant number. That’s one in four Americans. Compare that against the number
of primary care physicians in the United States. There are only 400,000– 400,000 primary care
physicians actively practicing in the United States. That’s half of the San
Francisco population– only 400,000. So if you divide
those two numbers, you find that each primary care
physician is now responsible for, on average, 165 patients
with chronic low back pain. Does anyone have an idea how
many patients a primary care physician would see? It’s about 800 on a
typical practice– up to 1,500 or 2,000 in the
more aggressive practices. And 165 will constitute a
significant portion of that. And not only do
we see this happen in increasing
proportions with patients with chronic low back pain,
when the CDC calls them, we also see that the patients
show up in primary care clinics more and more so with
chronic low back pain. This started at about 2.5% in
1997, and now is at about 5% of visits in 2009. So, by one measure, I wanted
to describe a problem. So, by one measure,
this is a big problem just by virtue of its size. Just by virtue of its size. Here’s the other
very cool movie. I hope it’s coming through. All right. So this is our lower
back, and these are all the important
anatomic structures that we know of in
medicine in the lower back. And I’m almost amazed
because each time– each month– when I
open up the journals, there’s always a case report or
two describing yet another way to explain low
back pain, perhaps, on other anatomic
structures involved. And, perhaps, that
could cause someone to have lower back pain. And it’s altogether highly
complex of a problem. There are just
categorically different ways of explaining low back pain. It could be neuropathic,
arthritic, discogenic, inflammatory, myopathic,
or ligamentis. And there are hundreds of
ways to explain low back pain. So, therefore, our
job as clinicians is, first of all, to
figure out if they’re important to diagnose,
that’ll explain the back pain. Tease it out, and help
the patient with it. This will involve clinical
history, [INAUDIBLE] quite involved. Reviewing of records. Performance of significant
number of diagnostic studies, including– and I have to
imagine many in the audience have had things like
X-ray, MRIs, CT– each of which, it would
reveal different aspects of the lower back or
other ways of explaining chronic low back pain. And what’s important, I think,
for patients to realize, is that this is highly complex. And it does take
time to go through these diagnostic studies. It does take time to
synthesize the data. At the end of the
day, we may not have a black and white answer. And, oftentimes,
we find ourselves– as a field and as
clinician and patients– having to go through a
series of therapeutic trials. We try different medications. We try different
interventional procedures. And I mention this
because I find this is important for
patients to understand. It does take time, when it
comes to medical approach to chronic low back pain
to tease things apart and to find the right solution. So the complexity list– the second dimension of this
big problem we’re facing. So, finally, I
wanted to demonstrate that back pain treatment is
oftentimes misunderstood. Back pain treatment with
medication, I should say, is oftentimes misunderstood. Has anyone here ever
been offered medications, like hydrocodone, oxycodone? Yeah. So this is oftentimes taken as,
perhaps, a first-line treatment for chronic low back pain. You can see the data from
the CDC in the charts that more and more patients
are getting opiate medication prescriptions at primary care
clinics around the country, from about 20% in 1999
to about 40% in 2009. So that’s about a
doubling of the range. So many patients
like you have been offered opiate medications, like
hydrocodone, like oxycodone. So I guess the
question is, so what? Why is that a problem? Well, even the
opiate medications are really great medications
for acute issues, like after a surgery,
after a fracture. We have found, in scientific
studies more and more so each and every
month, we’re finding– revealing, really–
issues of the chronic use of opiate medications,
for pain, in general, and perhaps even more so
in chronic low back pain. Some of these side effects,
or adverse effects, are very well appreciated,
like on the left-hand side– things like constipation,
things like sedation. Other adverse effects are
not so well-recognized. And I’d like to just
take a little time to go through each
and every one of them. OK. So starting from the top is a
phenomenon called tolerance. Tolerance is where the body,
after having been exposed to opiate medications
is now so used to it that the same dose
of opiate medications that were given before are
no longer effective. And the patient
needs larger doses to achieve some type of
additional pain relief. And I see heads are
nodding in the audience. A very, very common observation. And what I see in
clinic is patients who end up in this cycle
of dose escalation, increasing their dose,
develop new tolerance– increase the dose again,
develop new tolerances. Endless cycle. And it’s a cycle that
I would like to avoid. Another observation
is a mechanism called physical dependence. This is where the body– it’s
the flip side of tolerance, where the body is now so used
to having opiate medications. Now suppose you reduce the dose,
or suppose you skipped a dose– the body basically
reacts against it. Patient feels uncomfortable. Patient starts having
withdrawal symptoms. And that’s an unpleasant state
patients find themselves in. OK. So there are several other
not very well understood appreciated adverse effects,
like increased risk of fall, problems– this is secondary to the
sedation– dizziness, and a decreased– more like a prolonged reaction
time that comes with opiate use. Patients are more likely
to get into car accidents. This is studied much more so
in Europe than in the states. But they have found patients who
are taking opiates long term, taking large doses, may place
themselves at risk on the road. There’s a risk of
drug interactions– many antibiotics
and many sedative medications can interact
with opiate medications, placing patients at risk. And two very important– and I really need
to emphasize this– adverse effects of
chronic opiate use is reduced immunity and
reduced hormonal function. So reduced immunity means your
cells, your immune system, does not react as well as
it should to infections, placing patients at
greater risk of infections. And [INAUDIBLE] hormones
typically involve testosterone and estrogen. And
patients on large dose opiates will complain of things
like erectile dysfunction and sexual dysfunction. So thanks for your patience. I really wanted to
go over that list, because this is the
important aspect of misunderstood part of
medication use in pain management of low back pain. So, in contrast to
that, there are really only about 20 opiate
medications in pain. We, in the pain clinic, work
with about 207 medications. So opiate medications are
just 10% of what we do. And there are many,
many other opiate– excuse me– many other
non-opiate medications that are oftentimes
overlooked by other providers. These would be things like
neurotransmitter medications– medications like duloxetine,
gabapentin, pregabalin. Other nerve medications,
muscle medications, anti-inflammatory medications,
and hormonal medications– each one of these is
a good alternative to opiate medications. And when we work with patients
with chronic low back pain, because of all the side effects
we went through earlier, we like to avoid
the use of opiates. And then optimize
their medications, like these I’ve listed here. Oh. So the– there should be
about 200 medications. OK. So there should have been
about 200 medications flying through the screen just now,
but maybe it flew by too fast. We didn’t see that. OK. Well, so, OK. In relation to that, how
complex is does pain medicine? Just want to take a few minutes,
so this is a very interesting– this is what I do, this
is what Dr. Mackey does, in terms of pain medicine. And we find it
fascinating when we start cataloging how
complex our field really is. We’re working with, for
example, 108 important muscles of the body that
contribute to pain– 70-something nerves that
can contribute to pain. There are lots of
psychosocial factors that contribute to pain. About 400 different diagnoses
we need to work with. And, finally, choose
from 200 medications and 230 different
interventional procedures. Altogether, if we
really counted it, the number of possible
medication regimens is about the number of
atoms in the universe. But it’s something we can
handle at the pain clinic. Yes, sure. OK. So we have now
described what I believe is a hole our society
has thrown ourselves in. We know chronic low
back pain and medication use of this condition is a big
problem by virtue of the size, by virtue of the complexity,
by virtue of the misconceptions that are out there. So it’s a big problem. So how do we overcome this? Well, if we’re in the
hole, do we keep digging? Or should we somehow
climb out of this hole? So, again, really, the solution
is right there in front of you. The solution you
have already heard– started from this morning. Oh. Oh. Yes, that is the solution. That’s the simple version of it. No, actually, this
is the solution. That was the problem. Now here are the solutions. These are all the things
you heard about this morning and this afternoon– non-narcotic
medications, meditation, cognitive behavioral therapy. We identify parts
of the pain cycle that are affected
in all patients with pain, in patients
with chronic low back pain. We target those areas
in a team approach. And we help patients with pain. This is the solution
to medication use in chronic low back pain and
mulitmodal pain management. Another aspect of
this is to realize– remember earlier when we talked
about physical dependence, it’s very hard. Even though I understand and
patients understand opiate pain medications cause problems,
it is sometimes quite hard to come off of
opiate medications. It’s a problem that’s
well understood by us– we have a lot of
experience working with patients with this issue. And we have developed
specialized programs for it. And this, just like earlier, is
going to be interdisciplinary. It’s going to be
physicians, psychologists, physical therapists who
work with patients who are, should I say, stuck
on these medications, by optimizing their
non-narcotic medications, gradually reducing their
opiate medications, and then managing their
withdrawal symptoms. We even have an
inpatient program that’s in hospital–
it’s intensive, about a week stay,
where we help patients reduce their opiate
medications and plug in to a intensive
interdisciplinary pain management program. OK so that was my insider’s
perspective on the medication use in chronic low back pain. I’m going to switch
gears a little bit and just take a step back, and
offer some tips on medication use from a patient’s perspective
in chronic low back pain. I need to note that I’m
very happy to be here to talk about a topic that
I feel very strongly about. But, ultimately, I need
to say that this is not medical advice. I am talking in
generalities today. And if you plan to make any
changes to your medications, I would advise that you
chat with your physician. And everyone’s entitled
to a second opinion. And we’re available at the
Stanford Pain Management Center as well. All right. So the four tips I’d like
to discuss is, first of all, many patients have
this concern– the pain medicines
who hide their pain, therefore causing problems. The second concern patients
has about side effects that’s very reasonable– I will discuss
that a little bit. Third is about how
medications work. And what are their effects? And this is a little bit
subtle, so I will take some time to talk about it later. And, lastly, I always
remind all of my patients to do not forget other
aspects of their health. Do not forget other
aspects of their health. OK. So, first of all,
do pain medications really hide the pain,
therefore, causing problems? Patients who say, well, what
if I cannot detect some type of tissue injury, therefore,
causing more problems? And this could be catastrophic. The thing I’d
remind our patients is that non-opiate
medications are excellent, but they usually just
reduce the pain level and do not remove pain. There would still be
pain sensation that could be protective in nature. So the question now becomes,
if it doesn’t remove pain, why do we even take it? Why bother paying for the
medication, setting an alarm, taking the medication
on a daily basis if it doesn’t remove pain? From pain medicine’s
perspective, it is very important
to reduce pain signal. As Dr. Mackey had mentioned
earlier today, in the process called central sensitization. And here’s some animation– there we go. All right. So on the top is a
normal nerve transduction from the left to the right. On the right is the brain
and the spinal cord. And we send one signal over
to the brain and spinal cord, and that’s a normal
state of affairs. But if you have an
extremely active nerve, it keeps sending signal to
the brain or the spinal cord. Our brain and
spinal cord learns, like we do on a daily basis,
it learns about pain too. So over time, this
repetitive trains of stimulation coming
from the nerves causes changes in the
spinal cord and the brain and, therefore,
causing chronic pain. And that’s a
pathological process. It serves no protective role. And that process called
central sensitization is something I would like
to help patients with, with these non-narcotic
medications and non-opiate medications. So it does not hide pain. It reduces central
sensitization. Another aspect of this
that’s very important is I would like
patients to participate in a solution we talked
about earlier that involves psychology, meditation,
cognitive behavior therapy, physical therapy, home
exercise program, acupuncture. We would like to help
patients participate fully in each and every one
of these modalities. And, therefore, by reducing the
level of the pain they have, that they experience, they
can participate more fully and, therefore, get a bit more
benefit from some modalities. All right. We talked about how
pain medication does not hide the pain. Now I need to talk to you
about side effects that come with non-opiate
pain medications. So every medication will have
its unique set of side effects. And I’m always
amazed at the clinic because, on a
daily basis, I will hear about unusual
reactions to otherwise very common medications we
use in the pain clinic. And this is because everyone’s
just built differently. There are three billion gene– excuse me, three billion
base pairs in a genome– and each one of us is different. We all react differently
to the medications. So what does that leave us? We’re not at the stage yet where
we can predict side effects based on the genome. I think Dr. Mackey is
working towards that with several
projects at Stanford, but we’re not there yet. So we take an empirical
approach and practical approach. We start medications
at a low dose, and we increase it slowly. And we ask patients to
pay attention to any side effects they might experience. And we react to it. React to it by either not
increasing their doses fully. React to it by changing to
another class of medications. It’s also important to know that
these non-opiate medications, in terms of their prescription,
must be individualized. At the pain clinic, there
is a very popular medication that just so happens to be
FDA-approved for weight loss, for example. And then some patients
really like that. Yeah. And other medications
will cause weight gain. It just depends on the patient’s
situation in our medication choice. OK. We talked about medications
do not hide pain. We talked about the side
effects and the individuality when it comes to side effects. I’d like to talk a little
bit about the effect of non-opiate medications. I assume most of
you in the audience have taken antibiotics before. Right? And most of you have taken blood
pressure medication– well, many people have taken
blood pressure medication. And what’s different about
these two medications? Well, antibiotics are taken just
for a few days to a few weeks. And you take it until we know
that the infection has cleared. It’s meant for an acute
and limited episode. Blood pressure medications,
on the other hand– where we know we
know hypertension is the silent killer– blood pressure medication,
on the other hand, needs to be taken
on a regular basis, for the most part, regardless
of the blood pressure. It’s taken to protect you. And chronic pain
is, in many ways, analogous to hypertension. It is a chronic condition. And medication used for
a chronic low back pain, they’re often taken like
blood pressure medications, as in we would like to,
as we discussed earlier, reduce the signal going to
the brain and spinal cord. And we would like patients to
take many of these medications on a scheduled basis. This is particularly the
case for the neurotransmitter medications. Recent research
in brain research have found that,
on a daily basis, we generate new brain cells. On a daily basis, many
of these new brain cells do not incorporate into
the brain and they die off. But what we have found in
the use of neurotransmitter medications is that they promote
the survival of these brain cells. More of these brain cells
that are born on a daily basis will now be incorporated
into the brain. So not only do we get
smarter, our mood is better and our pain is less. And that takes about a
month to actually work. So that effect
takes about a month to actually work,
whereas the side effects of many of
these medications will manifest in
day one or day two. So this is why it is important
to work with your physician, and be a little bit patient for
the effects to really kick in. All right. So, lastly, this is a
very important point. Just do not forget
about the fundamentals. The circuitry of the
brain is build such that pain signal is the most
prominent and most salient signal of them all. And, unfortunately,
for many patients suffering from chronic
pain, the signal is so overwhelming
that they overlook other aspects of their health. I recall, I think
it was a patient who missed a colonoscopy from year
to year for about 30 years. But this is an important
part of their health care. Then they neglected
their blood pressure, neglected their diabetes. These are all not
good things to happen. And that list are all– and, [INAUDIBLE]
work, by the way. So that list are all the
preventative services recommended by the Agency for
Health Research and Quality– the AHRQ– that patients
are supposed to undergo. So, as a last point, please
don’t forget the other aspects of your health, as we focus
on the chronic low back pain. All right. So, in summary, we
talked about how medication use in
chronic low back pain is a little bit problematic
because of its size, because of its
complexity, and because of misunderstood nature
of many medications in chronic low back pain. We talked about the solutions– some simple, some
not so simple– but all involving multimodal
treatments, as you have been hearing today. We talked about the four tips
for non-opiate medication use in chronic lower back pain,
starting from the fact that they do not hide pain. We talked about
how the individuals will have very
individualized side effects to the same medications. We talked about how many
non-opiate medications have an effect by inducing
the body to change, not by the medication itself, by
inducing changes in the body. So, therefore, it takes time. Therefore, it requires patience. And, lastly, the
last point, just don’t forget about other
facets of your health. And I guess just
the very last thing that we are dealing with– the
number of atoms in a universe when we choose medications. So, all right. Thank you. [APPLAUSE]

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