Pharmacology Flashcards
Topical skin medications come in what (7) forms?
- Ointment
- Cream
- Lotion
- Solution
- Gel
- Foam
- Powder
Skin absorption is a passive process primarily through ____________ route. Secondary routes are transcellular and follicular.
intercellular
What is the rate-limiting step in cutaneous drug absorption?
Stratum corneum layer of the skin that is thick and consists of dead cells.
How are drugs that penetrated the skin distributed?
- blood vessels
- lymphatic system
What are three characteristics of an “ideal” topical drug?
- low molecular mass
- adequate solubility in both oil and water
- ability of the drug to “detach” from its vehicle/medium
We categorize some topicals by potency to determine dosing. ________ is determined by clinical endpoint.
Effectiveness
Which topical agent is occlusive and what does it mean?
Ointments and occlusive bandages/wraps. Occlusive agents are usually oily substances that work by coating the stratum corneum as well as the decreasing transepidermal water loss.
How does propylene glycol affect absorption of topical drugs?
Increases the hydration of stratum corneum and enhances desqamation (shedding the outermost layer). Very effective in disorders with retention hyperkeratosis (abnormality of routine skin desquamation).
Why some topical drugs are the most effective in use right after the shower?
The skin is at its best hydration after a shower.
Body location, surface-to-mass ratio, heat, electric current, microneedling and laser are all factors that
Affect absorption of topical drugs.
Correct diagnosis, moisture level of the lesion, type of medication and the method of its delivery are factors that affect
effectiveness of the drug.
Some rare potentially life-threatening hypersensitivities to OTC acne products are caused by what ingredients?
Benzoyl peroxide and salicylic acid. FDA recommendation is to limit the use to small affected areas for 3 days to test for hypersensitivity.
What is an excipients in the medication?
An inactive substance that serves as the vehicle or medium for a drug or other active substance.
When choosing the quantity of topical drugs, 1 palm equals to? What are FTUs?
1 palm equals to 1% of body surface area. FTU - fingertip unit that equals to 500mg of product.
What are the main functions of topical corticosteroids?
Generally
Modulates the production of various proteins by inducing or inhibiting gene transcription
Anti-inflammatory and immunosuppressive
- Inhibit inflammatory processes, neutrophil and monocyte recruitment
Antimitotic
- affect cell differentiation
Vasoconstrictive
What are the general principles in selecting the potency of corticosteroids in treatment?
Super high Potency:
* Severe Dermatoses - psoriasis, severe atopic dermatitis, severe contact dermatitis
* only for non-facial/non-intertriginous
Medium-High Potency:
* Mild to moderate - non-facial/non-intertriginous
Low-Potency:
* Eyelid and genital dermatoses for limited time periods
* Large body areas
What are the rules in administering topical corticosteroids?
Daily use and limitations
- Rubbing creams and ointments
- typically twice daily (increased frequency does not improve the effect); high potency ones may be used only once daily
- low-to-high potency limit to 3 months continuous use
- ultra-high potency limit to 3 weeks continuous use
What are some advice in using topical corticosteroids?
6
- Ointments have better absorption than creams but poorer adherence
Can alternate w/ creams for convenience - Application post-shower/bath increases absorption
- Inflammation increases absorption
- Avoid fluorinated formulations on the face (rosacea/perioral dermatitis)
- Avoid ointments in hairy areas or intertriginous areas
- Taper higher potency steroids
Name one corticosteroid drug for every potency.
What are the drugs used in fighting inflammation?
5
- Oral Isotretinoin (retinoid, inhibits sebaceous gland function and keratinization)
- Oral tetracyclines (keeps bacteria in check)
3.Topical Retinoids
4.Azlelaic Acid (neutralizes free radicals)
5.Topical Dapsone (inhibits production of reactive oxygen species)
What are the drugs used in targeting Cutibacterium Acnes?
3
- Benzoyl Peroxide (disrupts vital cell components)
- Topical and Oral antibiotics
- Azelaic Acid (inhibits protein synthesis)
What are the drugs used in counteracting increased sebum production?
4
- Oral Isotretinoin
- Oral contraceptives
- Spironolactone
- Clascoterone
Which drugs target follicular hyperprolifetation and abnormal desquamation?
- Topical Retinoids
- Oral Isotretinoin
- Azelaic Acid
- Salicylic Acid
What are retinoids?
How do they work?
What are they used for?
- Biologically they have similar activity to vitamin A. They bind to retinoid receptors, bind DNA sequences and activate gene transcriptions. The product of this transcription has a pharmacological effect.
- Reduce inflammation. Systemic ones also reduce sebum production. Reduce Cutibacterium Acne. Increase collagen production. Reduce epidermal hyperplasia and pigmentation by accelerating epicermal cell turnover.
- Both inflammatory and noninflammatory acne.
