Now, morphine is what we call the "gold standard" for opioid agonists.
We use it as a standard to measure the potency of newer opioids.
Morphine has been around for a really long time and you're probably already familiar with this drug
but I wanna tell you what I mean when we say it's the gold standard
for measuring the potency of newer opioids.
Take a look at this chart in your downloadable material.
If we treated morphine, as if you took it orally as one,
now I wanna compare it to non-opioids.
Aspirin which is a non-opioid, it has 1/360th of the pain relief of morphine.
Ibuprofen which is an NSAID, something you get over-the-counter also
but it's not an opioid, has 1/222th of the pain relief of oral morphine.
Now let's look at some true opioids.
Codeine has 1/10th to 3/20th of the pain relief of an oral morphine.
Oxycodone is 1.5 so this is the first medication in our chart that's a little bit stronger than morphine oral.
Morphine IV compared to morphine oral is three times as pain relieving, okay?
So why would that be?
Well remember, when you take a medication orally, it goes through the first pass effect in your liver.
That's why it has -- it gets kinda chewed up and the pain relief's only one.
When I give morphine IV, there's no first pass effect, it goes directly into your intravascular space.
That's why it's significantly more potent than oral IV.
Methadone is something that we use to treat people who are addicted
to medications is a three to four in comparison of oral morphine. But look at that last drug.
Fentanyl IV is 100 times more potent that oral morphine.
Okay, so this chart is just -- remember it's a proximate for you
but it's a good kinda frame of reference if you're thinking
which drug is more potent or stronger,
helps you understand the concept of why morphine is the gold standard for comparison,
morphine oral and lets you see how the rest of medications kind of fall in line.
Now, the beneficial effects of morphine, what we're usually after is pain relief,
it can also help people calm down, they have a sense of well-being, it'll suppress a cough,
and sometimes sedation can be considered a beneficial effect.
Now you might consider these adverse effects for some obvious reasons.
Respiratory depression is not what we're looking for in patients.
You wanna watch them closely when a patient is taking an opioid.
Constipation again, not something patients want but opioids cause that gut to kinda slow down.
The slower the gut is, the longer the waste stays in there,
the more water that's drawn out of it, and that's why a patient ends up being constipated.
Also, they have urinary retention, it's difficult for them to completely empty their bladders.
They have orthostatic hypotension because of vasodilation.
Kinda upsets their stomach and messes with their pupils.
They have cough suppression and reduced bowel motility.
So those are some of the things that could be categorized under adverse effects.
Now you might argue for different reasons on why we would put them
in the adverse effects or the beneficial effects.
We'd all agree respiratory depression, constipation, reduced bowel motility,
those probably aren't great ones but sometimes sedation can go into either category.
Don't worry about that right now.
We're gonna give you some more summaries and application and actual practice.
Respiratory depression hands down is a problem.
Opioids can cause respiratory depression.
So, when you have a patient who's taking an opioid, your job is to monitor them closely
particularly if it is a new medication that they're taking.
So, watch their vital signs, you would expect their blood pressure to be a little bit lower.
Watch their respiratory rate.
Now not everyone who takes an opioid is gonna stop breathing
but it should get them to be relaxed and their respiratory rate will be lower.
If it's getting like 13, 12, you need to start really paying attention that we'd probably have a problem.
But here's the key.
You have to know what the patient's normal respiratory rate is before you can see
how big an impact the medication has had?
So, you wanna watch their level of consciousness and their oxygen saturation.
Alright, so I don't wanna run through that list too quickly.
If I have a patient on opioids, usually the worst-case scenario is respiratory depression
because obviously if the patient isn't breathing well,
they're not perfusing the rest of their tissues well.
So, my job as a nurse is to monitor them very closely.
Their vital signs, their respiratory rate, their level of consciousness, and their oxygen saturation.
Remember, think back to those three classic signs of opioid overdose.
Patients can actually have an opioid overdose in a hospital
if the medication we're giving them is overwhelming their body for some reason.
So obviously coma would get your attention but respiratory depression was the number two sign, wasn't it?
So, watch your patient very closely.
Now if your patient is also taking another CNS depressant, the risk is even greater.
Okay, so now here's the slide I talked about.
Remember the first slide we had with like, good or bad or we could argue either way.
These are important adverse effects and I want you to understand why.
Now, that's not gonna kill you but it's surely uncomfortable for your patients.
So, the reason they have constipation is remember that gut, that peristalsis can kinda slow down on an opioid.
Now, I don't wanna put them on another medication that's anticholinergic
because remember, an anticholinergic effect dries your eye, dries your mouth, you have urinary retention,
and your gut slows down and you end up constipated with those medications too.
So, I don't ever wanna give two medications that have the same nasty side effect like constipation.
So, make sure in your mind you have clear opioids and anticholinergic drugs
are gonna put your patient at an increased risk for constipation.
The same thing goes for urinary retention.
Opioids cause urinary retention so you don't wanna give them with anticholinergic drugs either.
Remember, dry eye, dry mouth, urinary retention, and constipation are all side effects of anticholinergic drugs.
Put those two together, opioids and anticholinergics,
we're gonna have constipation and urinary retention problems.
Orthostatic hypotension puts your patient at increased risk for fall.
So, you're gonna wanna watch them very closely.
They may also have emesis, really upset your stomach.
I know I don't like taking opioids cause it makes my GI tract just go crazy.
So, if I have to take a pain medicine, I've gotta be in severe, severe pain.
But I have to take an antiemetic with it right away.
Now, the last one on this slide is elevated intracranial pressure.
Remember that intracranial pressure is the pressure inside your head.
It's made up of your brain tissue size, cerebral spinal fluid, and blood.
That's the pressure that's exerted inside your skull.
If someone has a head injury, they have a brain bleed or a trauma
and their brain in swelling, their intracranial pressure can be elevated or it goes up.
If it goes too high, they're gonna have significant brain damage.
If the patient has a decreased respiratory drive, they take an opioid,
you know it causes respiratory depression; it might cause an elevated CO2.
So, if the patient isn't on any other respiratory support and we suppress their respirations,
they're gonna have an elevated CO2 level which can cause vasodilation
and it can continue to elevate their intracranial pressure.
Also, if someone has a head injury, giving them an opioid might kind of blunt
any possible neurological changes so that's another reason we use them with caution.