Advanced Clinical Pharmacology

Pharmacology Basics Integumentary System Medications

Speaker 1: This is the lecture over the integumentary system medications. The integumentary system is made up of the skin, hair, and nails. The skin has three layers which all provide a different function and level of protection. Healthy skin is important because it provides the greatest defense to invasion disease-causing microorganisms. Integumentary medications are mostly available as topical treatments, unless it's a more severe problem which may require a systemic medication. Bacteria can wreak havoc on the skin. Acne is the most common bacterial disorder. The patient has comedones which is blackheads, and may have pustules or nodules. Topical vitamin A, or your retinoids antibiotics and oral contraceptives may be used. Topical benzoyl peroxide may be used, which inhibits bacterial growth and topical salycilic acid. If that sounds familiar, that's part of the compound that makes up aspirin. It may also be used, and that removes infected skin through shedding.

I wanted to take a second and just really emphasize the retinoids like Isotretinoin or Accutane. I think I'll call it Accutane, it's easier to say. These medications are used only for severe acne. They work by reducing the oil production that clogs the pores. A common side effect is photo sensitivity and patients must wear hats and sunscreens when they use these medications. Most importantly, though, care has to be taken with these retinoid medications because of the teratogenic effects. These are pregnancy category X. Pregnancy tests are usually performed on teen girls prior to dispensing this medication. There's an iPLEDGE Program and it requires registration of all distributors, prescribers, pharmacies, and all male and female patients prescribed Acutane. This is to ensure that all individuals know the teratogenic effects of this medication.

Lastly, for skin disorders with bacteria is rosacea. It's a type of skin irritation without pus. The patient may appear flush. It affects mostly adults. Something stress, hot temperatures, spicy foods, alcohol, these things can all aggravate symptoms. Treatment is topical medications, which is the same as for acne. Atopic dermatitis is also called eczema. It is an allergic disorder. Patients can have a scaly, itchy, skin on the face, hands, and feet. Treatment of course is to avoid those allergens, and topical corticosteroids like hydrocortisone can be used. With psoriasis, the skin cells mature abnormally fast. The dead cells and the healthy skin cells surface to be shed, but the dead skin cells don't shed quick enough. So there's a buildup of skin on the surface. Topical corticosteroids, low dose anti-histamines, salycilic acid, and phototherapy may be used.

We have seen corticosteroids like hydrocortisone used throughout a review of skin disorders. It's important to understand this class of medications because we will see them used throughout our study of pharmacology to treat not only skin disorders like psoriasis, but we'll see them used for the treatment of allergic disorders, GI disorders like colitis, arthritis, lupus, and breathing disorders, just to name a few. So let's look at this important drug. So the adrenal cortex on the kidneys makes three hormones. First is your corticosteroids, which primarily releases cortisol, a stress hormone. Mineralocorticoids release aldosterone which helps with salt and water balance, and lastly is the release of sex hormones.

So let's talk a little bit about this important hormone, cortisol. So cortisol is released in response to stress. It prepares our body for fight or flight and to spring into action. When an inflammatory cascade is started in our bodies, cortisol is part of the powerful anti-inflammatory response. Cortisol prevents the release of substances in the body that cause inflammation. Under stress, cortisol also increases blood sugar as a survival method so we can escape the threat. Putting energy into digesting lunch, preparing for [inaudible 00:04:45] optimizing the immune system, these become unimportant, these are not the priority when we're under stress. So cortisol suppresses immunity and decreases libido. Serotonin is our feel good neurotransmitter and this level is decreased with high levels of cortisol. Cortisol also helps with bone density, and when cortisol is increased, calcium absorption is decreased. Cortisol regulates metabolism of carbohydrates, proteins, and fats. And lastly cortisol, will increase sodium retention and potassium excretion.

All right. So corticosteroid medications are used when we need to decrease inflammation, because remember, it has a powerful anti-inflammatory effect. These medications are O-N-E, number one drug. They end in O-N-E like prednisone, hydrocortisone, and dexamethazone. Many skin disorders that we've reviewed use topical corticosteroid preparations, which may cause burning, itching, and irritation. Prednisone is a synthetic corticosteroid that mimics cortisol and may be taken orally or Ivy for more serious inflammations. Let's consider again what cortisol does and look at the side effects of prednisone. It should make more sense and be easier to remember. I think of sugar, salt, sex, sadness, sick, stop, and shrink bone when I think about the side effects of prednisone.

So first side effect for prednisone is hyperglycemia. Remember cortisol controls blood sugar, and we're getting more of it. With retention of salt, patients may have weight gain. Also because of the effects of metabolism and sugar libido is decreased. So for us, we have sexual dysfunction. Serotonin is lowered, so the S's for sadness. Depression may be for patients on these medications. The next S is for sick. Remember, cortisol suppresses immunity. So patients on prednisone can get sick easier. This is why patients who are always stressed can frequently become sick. Our body's natural cortisol takes a back seat when we're on these corticosteroid medications. So they must be stopped gradually so our body has a chance to kind of recover. Because of the cortisol's role in bone health and calcium, patients who take corticosteroids longterm may have an increased risk of osteoporosis.

A parasite is an organism that lives on or in a host and it gets its food from or at the expense of the host. They can cause disease in humans. Scabies is caused by a human itch mite that burrows into the skin. They're found in the webbing of fingers, and toes, and the axilla, and the groin, and they're treated with scabicides topically. Lice is a parasitic infection of the hair or body. They feed on blood and are treated with pediculicides. These are neurotoxins and may cause neurological side effects. So they have to be used as directed.

A virus is a tiny microorganism that depends on the host cell for survival. That's what makes them so difficult to kill. So we have human papillomavirus or HPV, and this is responsible for most of the cervical cancer in women and venereal warts in men and women. The treatment consists of cryosurgery to freeze the warts, and we now have an HPV vaccine to prevent this virus. Other examples of viruses are herpes simplex virus type one that's cold sores, herpes simplex type two are sexually transmitted, and herpes zoster is shingles, which causes a very painful blistery rash. HSV-1, HSV-2, and two and herpes zoster can be treated with oral antiviral medications. Antivirals generally end in V-I-R, like acyclovir.

It's important to note that acyclovir is not a cure for these disorders. The offending virus continues to live in the body between outbreaks. Most antiviral drugs don't actually kill the virus particles themselves as they do inhibit their reproduction. When we're thinking about side effects, think about V-I-R as the [inaudible 00:09:18] for vomiting, nausea, abdominal pain. I is for ill feeling, patients just don't feel well. And R is for rash and renal disease.

Speaker 2: So let's review a few fungi infections of the skin. So tinea infections. These can infect the hair, nail, skin, trunk, groin, or feet. Tinea pedis is athlete's foot. You can recognize many antifungals by A-Z-O-L-E, like clotrimazol. Candida infections are also known as yeast infections, and this can cause [inaudible 00:09:58] red rush. Antibiotics can change the delicate balance of organisms and yeast can grow too much. This can cause candida or yeast infections in the vagina. Over the counter miconazole which is a cream can be administered through vaginal applicators. Thrush is an oral candida where there are white plaques in the oral mucosa. Nystatin is usually ordered for this, and it's ordered to swish and swallow. Topical antifungals may cause stinging, pruritis, and erythema.

Burns are a condition that affect the skin. The common type of burn is first-degree. The skin is red and painful to touch and treatment is lidocaine containing topicals like solarcaine. Also running the area under cool water for 20 minutes and applying aloe vera can help. No better though, with a second-degree burn, a blister forms over the burn and is yellow in appearance. Treatment is topical antibiotic ointment and to cover with the sterile dressing. Third-degree burns affect all layers of the skin plus subcutaneous tissue and possibly muscle and bone. There is a great risk for infection and fluid loss with these burns. Emergency treatments include staining the airway and administering IV fluids. Antibiotics are given to prevent infection and analgesics are given to control pain. Medications to debris the wound and cover with sterile non-adherent dressings may be initiated. There are also medications like regranex, which may be given to stimulate new tissue granulation.

So here's the types of skin cancer. There are more than two million people who are diagnosed with skin cancer in the United States every year, and there are three different types. The most common type is a basal cell carcinoma. These rarely metastasize, which means spread. And the usual treatment is surgery or liquid nitrogen. Squamous cell carcinoma can metastasize. Usual treatment is surgical removal and possible radiation therapy. Melanoma is the most serious form of skin cancer, and they might appear on the skin suddenly without warning, or they can also develop on an existing [inaudible 00:12:17] or mole. They appear on the upper back torso, lower legs, head and neck. Malignant melanomas are an unpredictable cancer and can spread throughout the lymphatic system and the blood. Treatment consists of surgery, radiation, and chemotherapy. Early detection and treatment are very important with all three types.

As we finish, I just wanted to give you the A-B-C-Ds of melanoma. So in recognizing the changes in the skin, this is the best way to detect early melanoma. And the earlier it's detected the best we can treat it. You see ABCDs, and if you have a changing new or a different [inaudible 00:13:01], make an appointment to see a dermatologist as soon as possible. So here's the ABCs, A is for assymetry. One half is not like the other half. B is for border. There's an irregular scalloped or poorly defined border. C is for color. The color can be varied from one side to another. There are shades of tan, brown, or black, sometimes white, red, or blue. And D is for our diameter. With melanomas, they are usually greater than six millimeter, which is about the size of a pencil eraser. And when diagnosed though, they can be smaller. Well, this includes the section on integumentary medications. If you have any questions, let me know, bring them to class or to the farm cafe.