Yale 20: Opioids in Pain Management

June 14, 2024

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00:00Hi everyone. My name is Julia Joseph.
00:04I'm a current third year Internal
00:06Medicine resident at Yale New Haven
00:07Hospital and this is part two of
00:09our pain management series that I've
00:11created with the help of our palliative
00:13care faculty member, Doctor Persic.
00:15In our last video we discussed non
00:18opioid pain options and here we
00:20will focus on opioids largely again
00:23from the inpatient perspective.
00:25Shown here is
00:26The Who analgesic ladder.
00:28Our last video focused
00:30on step one analgesics.
00:32We are only going to briefly mention
00:34the Step 2 analgesics largely because
00:36they have fallen out of favor and the
00:38focus of our talk will be an intro
00:40to Step 3 analgesics that are listed here.
00:43Keep in mind that you may encounter
00:45patients who require further step up
00:47in therapy as noted here in Step 4,
00:49including PCA pumps and spinal stimulators.
00:54Our talk is divided into two parts.
00:56We will first discuss what the right
00:58drug for a patient might be by going
01:00through different types of opioids.
01:01We will then focus on dosing strategies.
01:05So the first question we want to
01:07answer is this the right drug?
01:09So let's dive in.
01:12Let's start with morphine,
01:14an old and very commonly used drug.
01:16It comes in many types of
01:18formulations including immediate
01:19and extended release, oral tablets,
01:21liquid form and sub Q amongst many others.
01:25So this allows you to use morphine
01:27in many types of patients.
01:29It's also very cheap and easily
01:31accessible for patients.
01:32So consider this when prescribing to
01:34a patient's outpatient's pharmacy.
01:36Low doses to start include two milligrams
01:40IV or five to 10 milligrams PO.
01:42Morphine is also the standard when
01:44it comes to comparing the dosing to
01:46other types of opioids where you
01:48can actually calculate a patient's
01:50daily MME requirement or morphine
01:52milligram equivalent.
01:52Finally,
01:53make sure to avoid this in patients
01:56with renal impairment because of the risk
01:58of accumulation of toxic metabolites.
02:01So patients,
02:01especially with a GFR of less than 45,
02:04make sure to avoid morphine.
02:08Oxycodone
02:09is another type of opioid that
02:10you're likely to encounter.
02:11It's a bit more potent than morphine
02:13with a ratio of two to three.
02:15It comes in immediate and
02:16sustained release forms in the
02:17common starting dose for it is
02:195 milligrams immediate release.
02:21Some data suggests
02:22that it may cause less delirium than
02:24morphine, but it's drawback is that
02:26there's No 4 formulation available.
02:28Dilaudid is much more potent than
02:31morphine with a ratio of one to four.
02:33Both PO and four formulations
02:35are available out of the three
02:37opioids we've mentioned so far,
02:39Dilaudid is much safer to use and is
02:41preferred to be used in renal patients.
02:44For starting doses,
02:45you can initially start with 0.25
02:48milligrams of IV or two milligrams PO.
02:53The next two medications that we'll
02:54talk about are ones that you're
02:56unlikely to actually prescribe,
02:58but you may care for patients
02:59who are on them.
03:00So these are some pearls
03:01that you should know.
03:02The 1st is fentanyl, which is not
03:04for patients who are opioid naive.
03:06It comes in patch form and you typically
03:09have to change the patch every 72 hours,
03:11but it takes 24 hours to
03:13reach the full effect.
03:15Like Dilaudid,
03:15it is safe to use in renal patients and
03:18is actually the preferred formulation
03:19in patients with a history of ESRD.
03:22Be aware that when using heat
03:23or patients who are spiking,
03:25high temperatures may end up having
03:27increased absorption from the patch.
03:29The patch is also not compatible with MRI,
03:32so if taken off before a study
03:34when the patient is down there,
03:36make sure it doesn't actually
03:37stay off or you may precipitate
03:39a pain crisis in your patient.
03:42You may also see patients who are on
03:44methadone that is used for chronic pain,
03:46especially for cancer pain.
03:47It's long acting and is very effective.
03:50It's safe in renal and liver patients as well
03:53because there are no active metabolites.
03:55The things to look out for is that it
03:57is associated with a prolonged QTC and
03:59has several drug drug interactions and
04:02also has a long half life if used for
04:06pain indication which is TID dosing.
04:08There is actually no special training
04:10or waiver that is required.
04:12Now, these are the weak
04:14opioids or the Step 2 opioids.
04:16If you remember from The Who
04:17ladder that was shown at the
04:19beginning of this presentation,
04:20we generally do not employ these.
04:23Codeine and hydrocodone are
04:25metabolized to morphine, which is how
04:27it provides its analgesic effect.
04:29The unpredictable metabolism, however,
04:31causes unpredictable side effects,
04:33and it's also hard to predict
04:35its analgesic effect.
04:36Tramadol or tramadol is a
04:39mixed opioid agonist in SNRI.
04:41It also carries a lot of
04:43different risks listed here.
04:45So in general,
04:46we recommend that you prescribe
04:48alternative pain options
04:49rather than ones listed here.
04:53Opioids as a class carry a lot
04:55of different adverse effects.
04:57Constipation is a very common one.
04:59So you always want to make sure
05:00your patient is on a bowel regimen.
05:02Sena and Miralax is listed
05:04here are first line.
05:05You can also prescribe peripheral
05:07MU opioid receptor antagonists
05:09or Pomoras such as methyl
05:11nitroxone if the patient
05:13is still having refractory
05:14Constipation to first line agents.
05:17But you want to make sure that your
05:18patient does not have malignant
05:20bowel involvement because it
05:21carries a risk of perforation.
05:23Nausea and pruritus or itching
05:25is also very common at the
05:27initiation of opioids.
05:29Myoclonus and opioid
05:30hyperalgesia is also reported,
05:32but usually quite rare.
05:34Somnolence and respiratory
05:36depression is a very common
05:38side effect and is one that is
05:39feared by a lot of internus.
05:41But in general, if the respiratory rate is
05:43greater than six or the patient is able
05:46to maintain O2 sets greater than 92%,
05:49you can typically monitor them and
05:51wait for the opioid to eventually wear
05:54off. You really want to try avoiding Narcan
05:56in these patients because
05:58precipitating a pain crisis can
06:01be very uncomfortable and
06:02sometimes even fatal for patients
06:04with certain comorbidities.
06:07All right, so we talked about whether
06:08the patient is on the right drug.
06:10Now, how do we know whether the
06:11patient is getting the right dose?
06:15So these are the reasonable
06:16starting doses for morphine,
06:18oxycodone and Dilaudid that is
06:19included here as a reference slide
06:22for patients who you're not sure
06:23where to start and are opioid naive.
06:28So an easy way to remember how to
06:30convert between all of these different
06:31opioids is the 1020 thirty rule.
06:3410 milligrams of four morphine
06:36equals 20 milligrams of oxycodone,
06:38which is equal to 30 milligrams of morphine.
06:41The Dilaudid dosing is not
06:42as easy as to remember,
06:43but I've included it here
06:44in case you wanted to know.
06:46So all of these are equal
06:48to 1.75 of four Dilaudid,
06:50which is equal to 7.5 of PO Dilaudid. So
06:55make sure to ask the patient about
06:57function and quality of life.
06:58So for example, what dose allows them to do
07:00a certain activity that's important to them.
07:02Make sure then that you're asking about
07:04comfort level and not just about pain.
07:06From there you should
07:08reassess the pain and adjust.
07:09If the patient is still
07:11in mild to moderate pain,
07:12increase the dose by 25 to 50%.
07:15If the patient is in moderate to severe pain,
07:18then you can increase the dose by 50 to 100%.
07:21In general, you should not increase
07:24long acting formulations by over 100%.
07:28What about dosing frequency? The first part
07:30is to decide if
07:31it's OK to keep a patient
07:33on PRN or scheduled dosing.
07:34If you notice a patient has to
07:36keep asking for pain medication,
07:38is not getting it at appropriate intervals,
07:40and is remaining in a lot of pain,
07:42then it may be best to keep the
07:44patient on a scheduled regimen.
07:45The next part is to decide
07:47based on the drug's half life.
07:49So for example, patients who are
07:51receiving IV pain medication,
07:53it may be appropriate to
07:55dose every 10 minutes.
07:56For IM it would be every 30 minutes,
07:58and for oral formulations,
07:59it could be every three to four hours.
08:02You should consider longer
08:03intervals in patients who have
08:05renal or hepatic failure.
08:07So how do we help this patient?
08:09Let's say you have a patient
08:11who's prescribed oxycodone,
08:125 milligrams every six hours PRN,
08:15and you notice that they're
08:16using all of their PRN doses.
08:17You talk to the patient and they tell you
08:19that the pain is being reduced by 80%,
08:21but the relief is only lasting 3 hours.
08:24By the time the patient is able
08:26to take the next PRN dose,
08:27their pain has escalated
08:28to an intolerable level.
08:30So in this situation,
08:31it makes sense to fix the dosing interval.
08:33Instead of the interval being every six
08:36hours, it should really be every three.
08:38You can also decide if it's worth putting
08:40the patient on a scheduled regimen
08:42instead of keeping them on APRN dosing.
08:44And eventually,
08:45it may be worth considering
08:46whether the patient should be
08:48on a long acting formulation.
08:51Finally,
08:51I've included this chart
08:52as an easy reference.
08:54It has morphine, Dilaudid,
08:57fentanyl, methadone, and oxycodone.
08:59And the chart includes
09:01the IV and PO conversions,
09:03the time of duration, its onset,
09:06and the time for peak concentration,
09:09as well as certain comments.
09:10So you can use this chart as
09:13a reference table as needed.
09:15So to summarize,
09:16morphine is a cheap opioid that comes
09:18in many types of formulations which
09:20should be avoided in renal patients.
09:22Oxycodone is associated with
09:23less delirium than morphine,
09:25but usually only the PO form
09:26is available on formulary.
09:28Dilaudid is much more potent than
09:30morphine and is safer to use in renal
09:33patients out of all three listed here.
09:35Be careful in those patients who come in
09:37with fentanyl patches as they're spiking
09:38high fevers or if they need to get an MRI.
09:41Watch out for QTC prolongation
09:43and drug drug interactions.
09:44And those patients on methadone,
09:46make sure to avoid prescribing weak
09:49opioids which include tramadol,
09:50hydrocodone, and Kodi.
09:52And finally,
09:53when deciding on a regimen,
09:54it really is based on the individual patient.
09:56So you should decide if a patient
09:58is more appropriate to be on a
10:00fixed schedule or APRN schedule
10:02and also decide the dosing interval
10:03based on the type of formulation
10:05in terms of the half life.
10:07So you can decide based on whether the
10:09patient is getting an IV form or APO regimen,
10:12for example.
10:15Finally, here are some sources that I
10:16used for my talk. Thanks for listening.