May 29, 2023

Hey all welcome back to the real life pharmacology podcast i’m your host pharmacist eric christensen thank you so much for listening today before we get into the drug of the day as always go check out snag your free 31-page pdf it is a study guide of the top 200 drugs definitely a no-brainer to go through uh refresh yourself with maybe

Some things that you that you’ve long forgotten or if you’re uh just getting into pharmacy school nursing school med school and uh really want a resource to kind of help you through uh your learnings throughout college definitely go check that out free pdf gonna gonna take only your email there so with that said let’s get into the drug

Of the day today and that is duloxetine so i have covered snris previously uh but i wanted to dig a little bit deeper on this drug specifically brand name of this medication is symbalta i have seen uh the brand name drazalma before and that is a sprinkle type product of duloxetine but by and large in clinical practice you’re going to see cymbalta used most

Often this is an snri it is also technically classified as an antidepressant and anxiety medication at times mechanistically in snri we’re going to inhibit serotonin and norepinephrine reuptake so essentially increase the activities of these two neurotransmitters in the brain and that’s going to potentially help treat depression help treat anxiety help treat

Various pain syndromes and interestingly uh off label stress incontinence can also be a potential use for this medication now in clinical practice where do i see it used the most it’s going to be depression and pain syndromes by far sometimes anxiety on occasion with depression and anxiety it is important to note uh that it’s gonna take a few weeks for this

Medication to really kind of ramp up and start working so really important patient education point so they don’t get uh impatient and quit the medication too early after a few days for example if they start taking it and they don’t they’re not feeling any better we got to make sure that we’ve educated them on that point that it’s going to take a little while let’s

Talk about dosing a little bit 30 milligrams is the usual starting dose that i’ve seen utilized once a day and from there we generally titrate or go up to 60 milligrams kind of as needed now we can go up to 90 and 100 a maximum of 120 milligrams per day i will say most of the evidence most of the literature or maybe i should say lack thereof we don’t have a lot

Of evidence supporting those higher doses in being more efficacious for various disease states whether it’s you know pain syndrome like fibromyalgia or neuropathy or osteoarthritis we don’t have a ton of evidence indicating that those higher dosages are beneficial but of course as with many drugs side effects are dose dependent so as you go up to those higher

Doses you’re more and more likely to potentially run into adverse effects one more thing on the the dosage form front there is a 20 milligram dose i i do see it occasionally i’m not a huge fan of of doing the the twice a day 20 milligrams if we don’t need it it might be an option for tapering down it might be an option if patients report pain at specific times

Of the day or they feel like maybe the medication is wearing off a little bit that might be a situation where we go to that twice daily uh dosing regimen but again i i generally tend to recommend staying with the once daily you know unless there’s a good reason or significant reason not to to do it once daily as you get to higher doses then i might encourage

Um splitting that up a little bit because as i’ll talk about adverse effects gi upset can happen a little bit and we if we give all that dose if we’re bumping up to 90 or 120 if we give all that at once and we may have a little bit more likelihood of of adverse effects there so again kind of you know a little bit of a gray area as far as you know how to dose

And and that sort of thing um but by and large if we’re at 30 or 60 milligrams or lower i’m generally going to be in the boat of trying to do once daily if we can all right let’s talk about those adverse effects i mentioned uh you’re hinted at gi upset that’s definitely something i have seen in practice i believe that percentages are in the ballpark of 10 to 20

Percent so nausea looking out for things like that cns changes can happen sedation potentially insomnia in some patients dizziness uh maybe confusion in rare rare cases increase in blood pressure uh sexual dysfunction so similar to the ssris duloxetine can cause uh sexual dysfunction that is something you might want to ask about similar to ssris we can have

Discontinuation syndrome so basically withdrawal symptoms from the medication if we stop it too quickly so always a good idea to try to taper your ssris and your snris like duloxetine in this situation if we taper too quickly what you might run into is symptoms like anxiety gi upset dizziness paresthesias can happen so kind of kind of tingling sensation uh

Interestingly uh several years ago i had a rare case of uh sweating so basically i was asked to consult on a on a possible drug induced sweating situation and we actually determined that it was likely due to duloxetine so we actually restarted the drug the sweating stopped and we tapered down at a little slower rate so kind of an interesting case i wouldn’t say

That’s incredibly common that you’re going to see that but if you note that we’ve just discontinued uh an snri like duloxetine and maybe we’re at a higher dose and we discontinued it quickly keep an eye out for some of those withdrawal symptoms because they can certainly happen one question that i definitely wanted to at least mention was conversions so oftentimes

You’ll get providers that want to switch to ssris to an snri like duloxetine okay so if the patient is at a low dose so let’s say they’re on sertraline 25 milligrams and and we want to go to uh duloxetine what would i recommend in that situation i would recommend just probably stopping the ssri and you know next day or whatever starting the duloxetine at the

Usual starting dose maybe 30 milligram once a day dose there as we get to higher doses let’s say you got somebody on uh circulating 200 milligrams a day and we want to get them over to duloxetine that’s a situation where we’re probably going to do some sort of cross taper so you know maybe you drop down the the sertraline to 150 or 100 milligrams as you’re

Starting the duloxetine at 30 milligrams low dose and then kind of slowly go down with the sertraline over time and start to taper up on the duloxetine so again that’s a situation where you know kind of a cross taper is going to be involved and you’re going to want to obviously take into account that patient experience and and how aggressive do we want to get

Them up to a target dose versus you know the urgency of the situation and you know we’d maybe want to be more on the cautious side if it we don’t feel like it’s urgent that we get that dosage up too quickly so those are just kind of some things to think about and something that definitely comes up in clinical practice thinking about that crosstaper type situation

As well as kind of switching from one to the other because oftentimes in mental health disorders things like that you know drugs sometimes don’t work right away and so we often have to switch or transition to other agents there all right so let’s take a quick break from our sponsor and i’ll wrap up with drug interactions if you’re in the market for pharmacist

Board certification study material like bcps bcacp bc mtms bcgp or naplex definitely go check out store story in addition to those resources we’ve got great books on case studies drug interactions real life clinical pearls all those links can be found at store and can be beneficial for all sorts of different health care professions

That deal with medications from nurses to nurse practitioners pas physicians med students definitely you can find a lot that’s beneficial and a lot of information that’s directly from real world experience which is sometimes difficult to get so again go support the sponsor support this podcast help keep it free for all to benefit from all those resources at store story all right so finishing up with drug interactions so knowing and understanding that duloxetine has an increase in serotonin activity uh that’s one of the easiest and first things to think about you’re gonna have additive serotonin type activity so any ssri tca maoi all these drugs can have additive serotonin activity and potentially

Increase the risk for serotonin syndrome other drugs i think is some of the the migraine medications like tryptans drug like tramadol those can also have additive serotonergic type activity a true contraindication so it shouldn’t use maois with duloxetine linaselids and other drug antibiotic with maoi type activity that you generally shouldn’t use with duloxetine

And then we’ve got sip interactions that i definitely think you should be aware of so duloxetine actually inhibits sip2d6 and i’ve talked about this with other agents as well bupropion being a classic example so if you want to go back and listen to bupropion i definitely talk about that a little bit more but give you a quick summary of some drugs that can have

Their concentrations increased when duloxetine is added or increased so drugs that are broken down by sip2d6 at least partially clozapine so antipsychotic and another antipsychotic risperidone propranolol is a good example of a drug that is broken down by sip 2d6 so adding duloxetine onto that could increase propranolol concentrations again propranolol being a

Non-selective beta-blocker there interestingly tamoxifen which i believe i have covered previously is activated it’s a pro drug so it’s activated by sip 2d6 so by giving duloxetine with tamoxifen we could actually reduce the effectiveness of tamoxifen in breast cancer so some important interactions to to pay attention to there via sip2d6 now duloxetine is broken

Down in part or significantly by sip1a2 so any drug that inhibits sip1a2 could increase duoxetine concentrations and obviously be potentially more more causative of adverse effects from duloxetine that i kind of covered previously so drugs that inhibit sip 1a2 and can increase duloxetine concentrations the two classic examples ciprofloxacin antibiotic used for

Infection definitely something you’re going to see out there in practice and another kind of classic cause of drug interactions is fluvoxamine this is an ssri so hopefully we aren’t using it together with duloxetine in the first place we should generally avoid using snris and ssris i will say i have seen that combination in practice not necessarily something i

Recommend or enjoy seeing but again fluvoxamine and its sip 182 inhibitory activity could increase uh the concentrations of duloxetine there in addition to cipro like i mentioned all right so i think that’s going to wrap up the podcast for today thank you so much for listening if you enjoyed this episode leave a rating review on itunes or wherever you’re listening

Share us with friends colleagues help us grow this podcast it’s free and obviously a good review of pharmacology and of course some of those things that you actually see out there in real life so again share us leave a rating review on itunes wherever you’re listening uh support the sponsor met at store s-u-r-e um you can go snag your free audible book

At store as well uh so that’s a good way to to help support this podcast as well if you’ve got suggestions comments i want to leave a complaint concern definitely uh don’t hesitate to reach out medieducation101 or you can track me down eric christensen pharmd bcgp bcps at linkedin with that i’m going to sign off for today thanks again

For listening take care and hope you have a great rest of your day

Transcribed from video
Duloxetine Pharmacology – Real Life Pharmacology Podcast By Eric Christianson