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Welcome back to the DeepDoc.
Today we're diving into dermatologic pharmacology.
We're really going to peel back the layers, you know, look at topical agents, the nursing side of things, and basically how we treat the body's biggest organ, the skin.
So our mission is to really nail down the key kernical stuff, skin function, common problems like acne, psoriasis, and the drugs we use right on the skin.
And this stuff matters because, well, getting the application right is pretty much everything.
It really is.
The skin's complex and that dictates how we approach treatment.
It does way more than just cover us up.
We're talking six key functions, protection, sensation, temp regulation, excretion, absorption, even vitamin D synthesis, but pharmacologically.
That slightly acidic surface pH around 4 .5 to 5 .5, that's a huge first line of defense.
Okay, why is that specific pH so important for the drugs we use?
Well, because that acidity naturally fights off microbes that like things more alkaline.
So if we slap on something really alkaline or, you know, something that seals the skin off too much, we might actually mess with that natural defense.
Structurally, you've got the epidermis on top, the main barrier, and the dermis underneath, which is full of blood vessels.
And if a topical drug gets past that epidermis, it can get absorbed into the bloodstream.
Suddenly, your topical treatment is systemic, not always what you want.
Okay.
Yeah, that makes sense.
So before we even get to the actual medicine, we need to talk about how it's delivered, the vehicle.
Exactly.
Ointments versus creams, it's not just about feel, it's about occlusion.
Ointments are oil -based, they're super -occlusive, they trap moisture, really push the drug into the skin.
So perfect for those really dry, thick, scaly patches.
Perfect.
But creams, they're water -based, less greasy, much better for bigger areas or skin that's moist or weeping, you don't want to trap all that moisture.
Right, that can make things worse.
Definitely.
And then there are gels and lotions too.
Yeah, gels are often good for helping the drug penetrate.
Lotions are great because they spread easily, like on hairy areas, and don't leave that heavy feel.
Understanding that range is step one.
Okay, step one is getting the drug in.
Step two,
what are we fighting once it's there?
Let's talk topical antimicrobials when that skin barrier breaks down.
Right.
So you're often dealing with common infections, maybe impetigo, usually caused by streptococcus pyogenes or Staphylococcus aureus.
Those are the main culprits.
If we start with antibacterials, Basitracin is a big one.
It's a polypeptide antibiotic.
It's mechanism, it stops bacteria from building their cell walls.
And Basitracin, that's one we pretty much only use topically, right?
Because it can be toxic if taken systemically.
Exactly that.
We can use its power topically because we expect minimal absorption.
Got it.
Then you've got that very common OTC mix, Neomycin and Polymixin B, often with Basitracin added in, Neosporin.
Oh yeah, everyone knows Neosporin.
Super popular.
But here's the heads up.
Using these combo products for a long time can actually make you more likely to develop skin allergies to them down the road.
That's important.
What else?
Mupurosen, Bactero, treats impetigo, sure, but it's really critical use.
Inside the nose.
Inside the nose, what?
To get rid of MRSA colonization applied intranasally twice a day.
It's a major infection control tactic, especially in hospitals.
Wow.
Okay.
That's specific.
And then there's silver sulfateazine,
Silvadine.
This is the go -to for preventing and treating infections in second and third degree burns.
And why topical for burns?
Think about it.
Severe burns wipe out the local blood supply.
So systemic antibiotics taken by mouth or IV, they just can't get to the burn side effectively.
Topical is really the only way to get the drug where it's needed.
Makes sense.
Any big warnings with Silvadine?
Absolutely crucial.
Do not use it if the patient is allergic to sulfur drugs, sulfonamides, big contraindication.
Okay.
Sulfa allergy check.
Got it.
So moving from bacteria, what about fungi?
These seem like tougher fights.
They often are.
Fungal infections can be really stubborn.
They might need wicks, sometimes months of treatment.
What are the common culprits here?
Usually Candida albicans that causes candidesis like thrush or dermatophytes.
Dermatophytes cause the tinea infections, you know, ringworm,
athlete's foot, jock itch.
And the treatments?
The azoles are very common.
Clotrimazole, myconazole.
You see them everywhere.
OTC and prescription.
Good for dermatophytes and Candida issues.
Okay.
And the last antimicrobial group,
viruses, specifically herpes simplex.
Right.
Topical antivirals, things like acyclover and Pensaclover used for acute outbreaks.
But how effective are they compared to, say, oral antivirals?
Generally systemic therapy is better, but topicals have their place for immediate relief during an outbreak.
The catch.
Compliance.
A cyclover needs to be applied like six times a day.
Pensaclover every two hours while you're awake.
Wow, that's a lot.
It is.
And it's critical for them to work.
Also, super important, whoever applies it, nurse or patient, must use a glove or a finger caught.
You don't want to spread that virus around.
Good point.
Okay, let's switch gears now.
Chronic stuff.
Acne and psoriasis.
Huge issues for many people.
Absolutely.
Let's start with acne.
We're targeting that bacteria, propionic bacterium acnes.
Benzoyl peroxide is a workhorse here.
Its action is sort of multipronged.
It's antibacterial, antiseptic, drying and key term here, keratolytic.
Keratolytic, meaning it breaks down that outer skin layer.
Exactly.
It slowly releases active oxygen, which helps soften and loosen that outer horny layer of skin.
Patients usually see improvement in about four to six weeks, but they should expect some side effects, peeling, redness, maybe some warmth.
That's pretty common.
Okay.
Now,
there's a big step up from benzoyl peroxide, isn't there?
Isotretinoin.
You mentioned the IPLDG -OR program earlier.
That sounds serious.
It is extremely serious.
Oral isotretinoin, formerly known as accutane, is for severe resistant cystic acne that hasn't responded to anything else.
And here's the critical point.
It's a pregnancy category X drug.
That means it's a proven human teratogen.
Causes severe birth defects.
Category X.
Which is why we have the mandatory IPLD's risk management program.
There's zero tolerance for pregnancy risk.
Any female patient who could become pregnant must be registered in the program, use two reliable forms of contraception simultaneously during treatment, and continue for one month after stopping the drug.
Regular pregnancy tests are required.
That's incredibly strict.
And doesn't it have mental health warnings, too?
Yes.
There have been reports linking isotretinoin to depression and, tragically, suicide or suicide attempts.
It's mandatory to counsel patients and families to watch for any mood changes and report them immediately.
It puts a huge responsibility on everyone involved.
No kidding.
Okay, so that's oral isotretinoin.
What about topical retinoids like tretinoin?
Still serious, but different level of risk.
Different, yes, but still require significant caution.
Tretinoin is topical, derived from vitamin A.
It also works by speeding up epidermal cell turnover, causing that skin peeling.
It's effective, reduces fatty acids, helps with collagen, but it makes the skin extremely sensitive.
So sun protection is non -negotiable.
Absolutely non -negotiable.
Strict sunscreen use is vital.
And any kind of skin trauma needs to be avoided, especially waxing.
That's a definite no -go, can rip the skin right off.
Yikes.
Okay, let's pivot to psoriasis now, that chronic immune -driven condition.
Where do we usually start treatment?
Often with topical corticosteroids, they're really the mainstays for many inflammatory skin conditions, including psoriasis.
They work because they're anti -inflammatory, anti -itch, anti -parietic, and they constrict blood vessels, vasoconstrictive.
And does the vehicle matter here too, like ointment versus cream?
Big time.
Remember how ointments are more occlusive?
That makes them the most potent delivery system for corticosterols.
Then gels, then creams, then lotions.
Potency varies.
Okay.
Any downsides to long -term corticosteroid use?
Yes.
A key one is tachyphylaxis.
That means over time, the skin can become less responsive, and the drug doesn't work as well.
You also worry about skin thinning and other local side effects with prolonged use, especially potent ones.
Got it.
Are there other non -steroid topicals for psoriasis, maybe other retinoids?
Yes.
Tazartine is another retinoid used for plaque psoriasis, and also acne sometimes.
But, warning bells again, tazartine is also pregnancy category X.
Same level of caution as isotretinoin regarding pregnancy requires a negative pregnancy test before starting.
Okay.
Another category X.
What else?
Calcipotrine.
This one's interesting.
It's a synthetic form of vitamin D3.
Its job is to help regulate the abnormal growth of skin cells, the keratinocytes, that causes those thick psoriatic plaques, slows them down.
Vitamin D for psoriasis, interesting.
Bacteria, fungi, viruses, acne, psoriasis.
What about those creepy crawlies?
Lysine scabies.
Yes, the ectoparasites.
We need ectoparasiticidal drugs for those.
Permethrin is a common one.
It's a synthetic pyrethroid, basically a neurotoxin for lysin mites used for head lice, pubic lice, and scabies.
Treatment isn't just about putting the cream on the person, is it?
Not at all.
This is critical.
You have to treat the environment too.
Decontaminate bedding, clothing, personal items, hot water, wash in high heat, dry, or seal things in plastic bags, and you absolutely must treat close contact simultaneously, even if they don't show symptoms yet, to prevent just passing it back and forth.
Right, that makes sense.
Are there newer options?
I heard something about not needing to comb out nits anymore.
Yes, that's a huge advance.
Newer drugs like spinosad and topical ivermectin have come out.
They're a big advantage.
They kill the live lice and prevent eggs, the nits, from atching.
So that incredibly tedious time -consuming knit -combing process often isn't necessary.
Big relief for parents and kids.
That is a big deal.
Okay, shifting to a few miscellaneous agents before we wrap up the drugs.
Monoxidil, Rogaine for hair growth.
Yep, topical monoxidil, it's a vasodilator, helps increase blood flow to the follicles used for androgenetic alopecia in both men and women.
Does it work right away?
Nope.
Patience is key.
It usually takes about four months of consistent use to see results.
And a practical tip, tell patients to be careful with heat right after applying it, like from a hairdryer.
It might reduce how effective it is.
Good tip.
All right, can't talk skin without talking sunscreens.
What's the main thing to know?
The FDA requirement, SPF 15 or higher, is needed to claim a product reduces the risk of skin cancer and early skin aging, not just sunburn protection.
And critically, it must provide broad spectrum protection, meaning both UVA and UVB rays, and generally avoid using them on infants under six months.
Keep them shaded.
Okay.
Last drug, Floresil.
Sounds serious antineoplastic.
It is.
Floresil or 5 -FU is used topically for pre -cancerous lesions, specifically actinic keratosis, and also for superficial basal cell carcinomas.
I thought it was at work.
It's an anti -metabolite.
It messes with DNA and RNA synthesis, basically destroying rapidly dividing cells, like those abnormal skin cells.
The special handling needed.
Absolutely.
Because it's cytotoxic, it has to be applied carefully.
Use a non -metallic applicator or wear gloves.
If you use fingers, wash them immediately afterward to prevent absorbing it yourself.
Okay.
Wow.
That's a lot of drugs, a lot of mechanisms, a lot of warnings.
This really drives home the question, how do we put all this pharmacology knowledge into safe, effective nursing practice?
Exactly.
The nursing process is absolutely vital here.
Let's start with assessment.
Always, always check for allergies.
And the key insight.
If someone's allergic to a systemic antibiotic, like penicillin pills, assume they might react to the topical form too.
Good rule of thumb.
What else in assessment?
Consider the drug concentration, how long it'll be on the skin, the condition of the skin, is it broken, inflamed, and the size of the area you're treating.
And definitely consider age.
Very young skin and older skin are generally thinner and more permeable.
That means a higher risk of the drug getting absorbed systemically.
Right.
More absorption risk in babies than the elderly.
Okay.
Implementation.
What are the key safety must -dos when applying these?
First, always gently cleanse the area before applying.
Get rid of any old medication, crusts, or debris.
Allows for better contact.
Second, wear gloves.
Always.
This protects you, the nurse, from absorbing the medication and it also prevents you from contaminating the patient's skin.
Double protection.
Makes sense.
If you're using a lotion or solution, shake it well before use.
Make sure it's properly mixed.
And strict adherence to the prescribed method and dose is just crucial.
Tell patients,
never double up on a missed dose.
Just apply it when they remember, unless it's almost time for the next dose and just skip the missed one.
Right.
No doubling up.
And what about those really high alert drugs, the category X ones?
Constant reinforcement.
For isotretinoin, tessarotene, and also finasteride, that's an oral drug for hair loss in men.
But also category X, the risk of severe birth defects is paramount.
We need to drill this home.
Women who are or might become pregnant should not even handle crushed or broken finasteride tablets without gloves because of absorption risk.
Wow.
Okay.
What other major patient education points?
Sun protection counseling is huge, especially for on tretinoin, but really for many of these conditions.
And for drugs that can have systemic effects, even if topical, like amicumod used for warts, actinic keratosis, superficial basal cell carcinoma patients need to know what to report.
Like what kind of effects?
Systemic things that suggest it's being absorbed more than intended, like a cough, upper respiratory infection symptoms, back pain, swollen lymph nodes, lymphadenopathy.
They need to report this.
Great summary of the process points.
So let's try to boil this down.
What are the absolute main takeaways from our dive today?
I'd say three big things.
One,
choosing the right vehicle ointment.
Cream gel lotion is fundamental.
It affects penetration and suitability for the skin condition.
Two, high alert protocols like IPLG for isotretinoin and the warnings for tessarotene are non -negotiable due to severe risks like teratogenicity.
Safety first.
And three, meticulous application technique, cleansing, gloves, correct amount frequency is essential for the drug to work properly and safely.
It's not just rubbing some cream on.
Definitely not.
So what does this all mean for you, our listener?
I think it shows just how much specialized knowledge is needed even for topical meds.
From simple basitrizone to potent retinoids or antineoplastics.
The skin isn't just a barrier, it's a complex organ and a very active site for therapy with real potential for systemic impact.
Couldn't agree more.
And here's something to maybe think about.
We talked about fungal infections being stubborn.
Consider how many patients you might encounter using OTC antifungal creams for maybe athlete's foot or ringworm just for a few weeks and it keeps coming back.
How often do we really counsel them that some of these infections, these dermatophytosis, might actually need continuous treatment for several weeks, even up to a year sometimes, to truly be cured?
Understanding that timeline can really change adherence and outcomes.
It's often missed.
That's a fantastic point.
A really critical detail often overlooked.
Something definitely worth pondering.
Well, thank you for joining us for this deep dive into dermatologic pharmacology.
From the entire Last Minute Lecture team, we wish you the very best in your continued learning.