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Antifungals – CRASH! Medical Review Series

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(Disclaimer: The medical information contained herein is intended for physician medical licensing exam review purposes only, and are not intended for diagnosis of any illness. If you think you may be suffering from any medical condition, you should consult your physician or seek immediate medical attention.)

So this will be a pretty quick talk on the antifungals there’s not a lot of fungal diseases that you need to know for the usmle and there’s not a whole lot of antifungal drugs in general that are used routinely so the antifungals are going to go over our gastro inhibitors which include easels pauline’s and l-little means we’re going to talk about ich i know camden’s

And then flu cytosine is another antifungal drug but we’re not going to spend any time talking about that but if you want to do your own research you can feel free i just don’t see that one coming up that often okay so what is an ergosterol inhibitor well what is your gastral or ghost rahl is basically cholesterol for fungus so as you know we have cholesterol

In our cells which stabilize the cell membrane it’s the same thing for fungus but they have their gastral so if you can inhibit the production of air got strahl or the function of ergosterol in any way then you can indeed cause fungal death so the three classes of your gosh draw inhibitors are easels polyenes and al elahh means okay so these are the drugs that

This this isn’t a comprehensive list of drugs these are just the most common to come up and the ones that are in blue are topical the ones that are in red are systemic so oral or iv and the ones that are in purple can be either so we have clitoral missile and ketoconazole fluconazole itraconazole pose a conical laura conical and then the poly means we have nice

Statin which nystatin is a swish and swallow so you might think that that’s oral but nystatin is not at all absorbed so it really is topical amphotericin b and that out of the ll means we have terbinafine so the azole antifungals so we’re talking about this first group here the term is all through bora con is all this these are probably the most widely prescribed

Antifungals and they have a really broad spectrum and it includes candida which is the most common fungal disease that gets treatment in the united states and it also is effective against the fungal lung diseases like histoplasmosis blastomycosis and coccidia mitosis so for skin infections that you can use topical but as far as tinea capitis or internal infections

Then you need to use one of the systemic agents so if a patient has if a patient just has athlete’s foot you can use clip trim azole the patient has candidal vaginitis you can use ketoconazole but if a patient has tinea capitis then you need to use something like it reconnaissance has a disseminated candida mia then you’re going to need to use a an iv form so

All of these drugs are pregnancy class c with the exception of oricon izl so if a woman is pregnant you really need to weigh the risks of whether or not you want to use this drug or not there’s actually really only one of two drugs that are pregnancy class b out of the antifungals which are amphotericin b and terbinafine okay so it reconnaissance or treatment for

The de mattify tosi’s so that would be like tinea capitis tinney icarus tinea pedis athlete’s foot and it’s also used for onychomycosis which is when you get the fungal infection underneath the nail fluconazole is the treatment of choice for cryptococcal meningitis and the reason for this is because it’s got a great penetration into the cerebral spinal fluid and

That’s that unique out of the other antifungals of the other hazel antifungals so so fluconazole is used as treatment for cryptococcal meningitis and it’s also used as proper laxus vorak on izl is used as treatment for invasive aspergillosis so those are three unique uses of a specific azole antifungals otherwise you just need to know when you use topical which

Is skin infections and when you use systemic which is tinea capitis and internal infections so the poly means what they do is they bind air got straw and so by binding your gas trawl they basically poke holes in the fungal cell membrane so amphotericin b is something we want to avoid and that’s because the adverse effects are significant i should note that with

The easels the adverse effects are primarily anaphylaxis and cytochrome p450 inhibition and so in general if the patient doesn’t show any allergic symptoms or they aren’t on a lot of drugs then we’re usually not concerned with amphotericin b on the other hand there’s notable hepatic toxicity and nephrotoxicity and that cumulates over time so the longer they’re on

Amphotericin b the worse it is there’s new formulations of amphotericin b called liposomal amphotericin b which reduce some of these adverse effects but they’re still there so we try not to give patients on this drug if we can avoid it so generally amphotericin b is going to be used patients with life-threatening mycoses and it does have a wide spectrum and it is

Very strong and very effective but like i said because of the adverse effects we try not to use it so when you see a pateros and bia when you’re going to prescribe a patek amphotericin b is in life-threatening cases of fungal pneumonia patients with mucormycosis which is a fungal infection of the respiratory tract particularly the upper respiratory tract patients

That have cryptococcal meningitis and in patients with disseminated infections note that fluconazole is our drug of choice for cryptococcal meningitis but in patients that have refractory cryptococcal meningitis then we go ahead and prescribe and patterson be another one of the poly and this works the same way as amphotericin b but it’s not absorbed so it doesn’t

Have nearly the it doesn’t have any of the problems that amphotericin b has as far as side-effects is nice statin and you’ve heard this drug before this drug is a swish and swallow and it’s used very frequently for or esophageal thrush so or esophageal thrush can happen if you’re on an antibiotic and all of a sudden get a candida infection of your mouth or of your

Esophagus and this is common in children i nice dan is also used as a appointment for vaginal candidiasis and for inter trigonis candida infections so it’s used topically remember swish and swallow it’s still topical because it’s not being absorbed and in general nystatin is very well tolerated so remember nystatin particularly with the or esophageal brush and

With vaginal candidiasis so the a lola means we have terbinafine and terbinafine is an oral drug and it’s administered primarily for the treatment of onychomycosis now the reason that we like to use terbinafine and onychomycosis is because it actually has been shown to be superior to it reconnaissance aim side-effects or drug interactions as it reconnaissance so

If we can use terbinafine we prefer to use to benefit the adverse effects are primarily mild gi upset and and so this should be your your treatment of choice if you’re presented with this for onychomycosis otherwise it’s reconnaissance fine but this is this is probably this this would be the best so here’s the akai no candace we have caps of fung gun micha funkin

And adju love hungin now the kind of cannons block beta glucan synthase and this is an enzyme necessary for cell wall formation and all of these are iv and they’re well tolerated and these are used for esophageal candidates more severe esophageal candidiasis invasive candidiasis and canden emia so this is kind of your middle-of-the-road antifungal if we can’t use

Our easels if they’re not if the disease is not responding to the easels but we want to avoid amphotericin be the kind of cannons are sort of our second line of choice so severe esophageal candidiasis i should say that’s not responsive to hazel’s or nystatin invasive candidiasis and candida mia if we want to avoid using amphotericin b which we usually do want to

Avoid using amphotericin b the kind of cannons are in general well tolerated and they are also pregnancy class c

Transcribed from video
Antifungals – CRASH! Medical Review Series By Paul Bolin M.D.