Lecture 1: Derm Disorders (General)

What is the role of skin in drug absorption?

Protects body from harmful external agents

What are the 3 regions of the skin?

Epidermis

• Outermost, thin layer of skin

• Stratum corneum at surface

• Regulates water content of skin

• Controls drug transport into lower layers & systemic circulation

Demis

• Middle layer

• Thicker than epidermis

• Contains nerve endings, vasculature, & hair follicles

Hypodermic

• Provides nourishment & cushioning for upper 2 layers

What must a drug applied topically must be?

Released from its vehicle to exert an effect at desired site of activity

What are creams?

• Oil-in-water emulsions

• Quickly absorbed into skin

• Allows some fluid to pass

• Use on broken skin & open weeping lesions

What are gels?

• Easy to apply

• Rapidly absorbed

• “Cooling“ & drying effect

• May contain alc

  • May cause irritation or burning when applied to open lesions

What are lotions?

• Oil-in-water emulsions (more % water)

• Easy to apply in hair areas

• Can be applied over large areas

What are ointments?

• Water-in-oil emulsions

  • Contain petrolatum

• Greasy texture, high lipid content

• Provide protective film to impede evaporation of water from wound area

  • Ability to retain moisture

• Not appropriate for open lesions, puncture wounds, infected areas, or lacerations

  • Occlusive effect

  • Leads to maceration & further inflammation

  • Promote bacterial growth

What are sprays?

• Convienent

• Easy to apply to touch affected areas

• May constant propellants that can cause inflammation

• May contain alc, which can cause drying & irritation

• Application

  • Hold container 6 inches from skin

  • Spray affected areas may constant for 1-3 seconds

What are anesthetics active ingredients?

• Benzocaine

• Lidocaine

• Pramoxine

What is the MOA of anesthetics?

• Interrupt transmission of electrical impulses along nerves

• Inactivating sodium channels in sensory neurons

What are the uses for anesthetics?

• Temporary relief of pain from minor wounds, burns, & sunburns

• Relieve itching

Who can anesthetics be used in?

All but </= 2 years old

What is benzocaine 20%?

Dermoplast First Aid Spray

What is lidocaine 4%?

Alicante Severe Sunburn Gel

What is neomycin sulfate (3.5 mg); polymyxin B sulfate (10,000 units); Pramoxine HCl (10 mg)?

Neosporin & Pain Relief Dual Action Cream

What is astringents active ingredient (cosmetic)?

Aluminum acetate 5% (Burow’s solution)

What is the MOA of astringents?

• Cool & dry skin through evaporation

• Induce vasoconstriction

• Reduces blood flow to inflamed tissue

What is the use for astringents?

Decrease weeping, oozing, or discharge

What is the dosing for astringents?

• Soak affected areas May constant

  • 15-30 mins 3-4x daily

• Wet dressing or compress

  • Apply to affected areas 20-30 mins 4-6 times daily

Who can use astringents?

All but </= 2 years

What is aluminum acetate 5%?

Burow’s Solution

What is aluminum sulfate 1347 mg; calcium acetate 952 mg?

Domeboro Astringent Solution Powder Packets

What are first aid antibiotics?

• Bactiracin

• Neomycin

• Polymyxin B sulfate

What is the MOA for bacitracin?

Inhibits cell wall synthesis (gram pos bacteria)

What is the MOA for neomycin?

• Aminoglycoside antibiotic

• Inhibits protein synthesis (gram neg bacteria)

What is the MOA of polymyxin B?

Causes leakage of intracellular constituents (gram neg bacteria)

What are first aid antibiotics the only exception to?

Putting ointment on open wound/puncture

What is the use of first aid antibiotics?

• Prevention of infection in minor acute skin injuries

• Not treatment

What is the dosing of first aid antibiotics?

• Apply 1-3 times a day

• Apply to skin injury after cleansing & before applying a sterile dressing

What are most first aid antibiotics?

Ointments

What is there a higher incidence with neomycin?

Allergic contact dermatitis

Who can use first aid antibiotics?

All but < 2 years

What is bacitracin; neomycin; polymyxin B sulfate?

Neosporin

What is bacitracin; polymyxin B sulfate? (No irritating neomycin)

Polysporin

What are the first aid antiseptics antive ingredients?

• Chlorhexidine

• Hydrogen peroxide

• Povidone-iodine solution

What is the MOA of first aid antiseptics?

Destroy or inhibit growth of microorganisms in tissues

What are the uses for first aid antiseptics?

• Prevent infections

• Promote healing

Who can use first aid antiseptics?

All but <2 years

What is chlorhexidine?

Hibiclens Skin Cleanser

What is povidone-iodine?

Betadine Antiseptic Solution

What are hydrocortisone active ingredients?

Hydrocortisone 0.5% & 1% (1% more common)

What is the MOA of hydrocortisone?

• Vasoconstriction

• Reduces inflammation & pruritis

What are uses for hydrocortisone?

• Minor skin irritations

• Itching

• Rashes

What are warnings of hydrocortisone?

• Do not apply to eye & eyelids

• Do not use w/ dressings/bandages

What is the dosing of hydrocortisone?

Apply 3-4x daily

Who can use hydrocortisone?

All but <2 years

What is hydrocortisone cream 1% or 0.5%?

Cortaid Cream

What are skin protectants active ingredients (barrier)?

• Petrolatum

• White petrolatum

• Dimethicone

• Zinc oxide

• Glycerin

• Lanolin

• Cocoa butter

• Colloidal oatmeal

What are the uses of skin protectants?

• Protect injured area from irritation caused by friction & rubbing

• Prevent during of stratum corneum

• Make injured area less painful

What is the dosing of skin protectants?

Apply 2-3x daily

Who can use skin protectants?

All but <2 years

What is petrolatum?

Aquaphor Healing Ointment

What is white petrolatum?

Desitin Multi-Purpose Healing Ointment

What is glycerin?

Neutrogena Norwegian Formula Hand Cream

What is cocoa butter?

Palmer’s Cocoa Butter Formula