March 28, 2023

Pharmacology, adverse effects, and important drug interactions for buspirone.

Well welcome back to the real-life pharmacology podcast i’m your host pharmacist erik christensen and today i’m gonna be covering buspirone which the brand name of this medication is buspar it’s generic kind of classification is an anti-anxiety type medication and i would say in clinical practice that’s probably the most common reason you’re gonna see this medication

Utilized on occasion i rarely have seen it used for depression as far as augmentation and using it with other antidepressant agents in patients who are struggling to get those symptoms under control but i would say that’s pretty rare there in general so with buspirone the mechanism of action is really not totally well understood as far as its role in managing and

Helping anxiety symptoms now there is some theories some suggested mechanism of actions that we we might think that this medication works through so when you think of a medication that might work for depression might work for anxiety we probably think of serotonergic activities so that’s one of the the main mechanisms that are educated guess or best guess is

That it is a partial agonist at five ht1 receptors potentially 5-ht 2 as well so having that agnus stimulating type activity you might hypothesize that’s the reason why we may see some anti-anxiety antidepressant type benefit with this medication now there is one other suggested mechanism that it does have some mild dopamine blocking blocking activity so i’ll

Talk about that a little bit as far as adverse effect profile and kind of a rare situation that you may come up against with dosing i think one of the bigger downsides with buspirone is that it’s got a very short half-life and so this medication is dose generally two to three times per day so in patients where you’ve got difficulty with adherence may be a very

Busy schedule that type of thing asking a patient to take a medication two or even three times a day i can be a little bit more challenging so that’s definitely more of a disadvantage with this type of medication one other disadvantage is kind of similar to let’s let’s say the ssris these buspirone takes a while to work so you’re not generally going to get get

That instant relief of anxiety you know it’s gonna take generally a few weeks to really start to show some benefit in most cases there so that can definitely be a downside advantages of buspirone compared to you know other anti-anxiety medications like benzodiazepines for example so tolerability buspirone is generally very well tolerated and particularly in our

Elderly population we don’t really run the risk of many active metabolites or those type of issues so that can be really a beneficial thing when we compare buspirone maybe to benzodiazepines for example which we should know that you know benzodiazepines have a ton of nasty side effects in geriatric patients from you know forrest a sedation to confusion and so on

And so forth there another advantage again kind of using that comparison of benzodiazepines is that buspirone is not a controlled substance so you know risk of addiction depends really isn’t there quite like it is for the the benzos so just some good comparisons i think to remember with buspirone there and you know why it might be advantageous to use that medic

This medication or why it you know might not work in certain situations as well adverse effect profile again usually pretty well tolerated at least in my experience from what i’ve seen i keep an eye out for any medication that kind of works on the brain and works on those receptors looking out for any cns changes you know whether it’s dizziness sedation confusion

Those type of things maybe some mild gi adverse effects but you know it’s it’s nothing major you know not you know if you compare it to you know metformin and other drugs that have you know well known ability to cause gi upset it’s definitely nowhere near that type of frequency now a couple of things that i did want to mention that kind of tie in to the purported

Mechanism of action so serotonin agonist activity there is potential you’ll see precautions drug interactions things of that nature for serotonin syndrome so your ssris your tca and so on and so forth that could be a cumulative type effect again this is clinical reasoning looking at the patient or reusing high doses you know have they had a history of serotonin

Syndrome or something in the past assessing that patient clinically and other medications that they’re on can really help us determine okay is this likely going to be a significant issue or something we need to monitor closely or is it not going to be that big a deal the other one there have been cases of pseudo parkinson’s type symptoms akathisia that those type

Of symptoms movements disorders so keep that if you maybe have a happen to have a patient on you know cinema for parkinson’s for example or if you’re on other dopamine blocking agents you know antipsychotics things of that nature you you could potentially get a little bit of an additive effect and again it’s kind of got this potentially weak dopamine blockade and

That may lead to an increased incidence of those movement disorders again i haven’t seen this in clinical practice personally but there is some literature out there case reports and things of that like that that may indicate that this is at least possible so something to think about again something that’s not very common at all from a kinetics perspective the short

Half-life i mentioned we need frequent dosing with this medication unfortunately there is a very high first pass metabolism with buspirone as well so i think that’s just an important thing to note there so let’s take a quick break here from our sponsor and then we’ll get into drug interactions after the break if you’re a pharmacist in the market for board certification

Study material whether it be nap lex bcps ambulatory care geriatrics or medication therapy management certification i definitely go check out meta slash store sto re in addition we’ve got other professional resources as well so if you’re a you know nurse physician student in any field that requires medication education pharmacology things of that nature

We do have a couple of books on audible which you can actually get your first one for free if you’ve never tried audible so definitely a cool little perk there you can get six to eight hours of case studies and drug interactions and good clinical discussion within one of those books again you find that link along with all the other resources we have at med ed

101 dot-com / store sto re now finishing up on drug interactions muse firown’ i would say there there is definitely potential for a significant number of drug interactions the clinical relevance and and how significant that is is is maybe a little bit up for debate so buspirone is broken down by sip three a four okay so that’s ultimately going to lead to a lot of

Potential drugs that could impact that three or four enzyme and raise or lower concentrations of buspirone respectively so if you’ve got a sip three a four inhibitor just keep an eye out look out for you know signs and symptoms of adverse effects toxicity from buspirone so your classic three a-four inhibitors grapefruit juice some of the calcium channel blockers

Some of them the macrolide antibiotics like clarithromycin azole antifungals those are just some some good examples of drugs that can inhibit sip three a four and could raise concentrations of buspirone now if you’ve got an inducer onboard carbamazepine the st. john’s wort things of that nature that could potentially reduce or lower concentrations of buspirone

So in that setting you might see a patient that’s had their anxiety very well controlled on buspirone maybe we start one of these inducers and now all of a sudden they’re not controlled anymore because the concentrations have been lowered thereby this type of drug interaction so just think about some of those medications and remember that 3 a 4 is a player with

Buspirone and that we’re going to probably in most situations clinically monitor that patient and then of course the the other drug interaction i really wanted to point out was the serotonergic activity where this drug does potentially have some serotonin agonist activities so any drug that’s gonna raise serotonin your tramadol is your ssris snris we do have that

Theoretical risk however low that maybe depending upon that patient clinical situation so that’s going to wrap it up for today thanks for listening if you enjoy the the podcast you’ll definitely enjoy enjoy the free resource from a real life pharmacology com it’s a 31 page pdf of the top 200 drugs and i pick out the most important pearls that you need to know so a

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And there so take care thanks for listening and have a great rest of your day

Transcribed from video
Buspirone Pharmacology By Eric Christianson