Lec. 18 - Drugs and Cosmetics Flashcards
What is the main difference in people’s skins
The amount of melanin they have
How is melanin introduced in the skin?
Melanocytes produce melanin pigment and deposit it into keratinocytes
Is skin thickness consistent across the body? How can this be utilized in terms of therapeutics?
Varies
Ex. behind the ears thinner, good place to apply patches (such as for motion sickness)
Describe psoriasis
Patches of abnormal skin, caused by high skin cell turnover rate, leaving behind keratinocytes with plaque
Name some methods of treating psoriasis
Topical:
- Corticosteroids
- Vitamin D3
Systemic:
-Retinoids
Phototherapy:
-UV light exposure
Biological:
-Monoclonal antibodies
What are the 2 types of UV rays?
What’s the difference.
UVA and UVB rays (different wavelengths, penetrate skin to different depths)
UVA -> deeper penetration
UVB -> greater exposure
What are the 3 types of cancer?
Basal cell carcinoma
Squamous cell carcinoma
Melanoma (most dangerous)
How is sunscreen strength measured?
What does it represent?
SPF -> Sun Protective Factors
Measure of how long you can stay outside vs without sunscreen
What are the minimum requirements for good sunscreen?
-Broad-spectrum (protects against UVA and UVB)
-SPF 15 in winter
SPF 30 in summer
What are problems that can occur with acne (4)?
- Occlusion of pilosebaceous duct (where hair usually comes out)
- Bacterial colonization of the duct
- Increased sebum secretion
- Inflammed sebaceous gland
Name 3 ‘types’/stages of acne
1) Oxidized sebum (blackhead)
2) Trapped sebum (whitehead)
3) Bacteria/leukocytes accumulation
Describe what happens in the case of a blackhead
Sebum is blocked, accumulates at surface of open-pore, is oxidized (causes color)
Describe what happens in the case of a whitehead
Sebum is trapped below skin
What is hyperkeratosis?
Accumulation of keratin & sebum;
Bacteria proliferates;
Leads to inflammation -> rupture
What effect can androgens have on acne?
Androgens (particularly testosterone) can cause increased sebum production
Thus, males during puberty are more vulnerable to acne
Name the 4 targets for acne treatment, what this accomplishes and name some drugs that accomplish this
1) Normalize keratinization
- Stops plugging of follicle
- Retinoids (topical or systemic administration)
2) Reduce bacteria
- No infection or inflammation
- Antibiotics
- Retinoids have (indirect) anti-bacterial effect
3) Inhibit sebaceous gland
- Sebum -> allows bacteria to grow
- Accutane (and other retinoids)
- Hormonal therapy
4) Decrease inflammation
- Corticosteroids
- NSAIDs
- Retinoids
Name 2 useful retinoids to treat acne
Tretinoin & Isotretinoin
What is a retinoid?
Vitamin A derivative
I) How do retinoids act in the body?
II) What process do they have a major role in?
I) Act as hormones and alter gene expression
II) Cellular Differentiation
How does retinol (vitamin A derivative) circulate in the body?
What attribute of retinol is the cause for this?
Retinol is not water soluble, so it binds Retinol-binding protein to circulate
Describe the pharmacodynamics of retinoids (7)
- Circulates bound to Retinol Binding protein
- Interacts with retinol receptor, enters cell
- Binds Retinoid binding protein in cell
- Enzymes convert to retinaldehyde, then retinoic acid
- Retinoic acid binds Retinoic Acid Binding Protein, transported to nucleus
- 2 Retinoic acids -> bind heterodimer receptor (RAR RXR)
- Alters gene expression
How does retinoid altering gene expression affect keratinocytes? (3)
- Decrease sebum production
- Anti-bacterial activity -> decreased inflammation
- Sebum changes (less fostering of bacterial growth)
Describe side effects of retinoids
- They are teratogen -> can cause fetal abnormalities (malformed face, intellectual disabilities)
- Isotretinoin -> inflammatory bowel disease in people with a history of intestinal disorders
What are some risks of cosmeceuticals (5)?
- Trace metals present
- Phthalates present
- Could damage skin barrier
- Possibly carcinogenic in high doses
- Possible endocrine/reproductive damage
How does herpes stay forever?
After first infection, goes into nerve ending and lies latent in trigeminal ganglion
What nomenclature is most often seen in drugs treating herpes? Give an example
Ending in -vir
Ex. Acyclovir
How do antiviral drugs work?
AcycloGTP inhibits viral DNA polymerase, preventing viral proliferation
How does hair get its pigment
Melanocytes deposit pigment in hair follicles
Describe the ‘life cycle’ of a hair
- Anagen active growth phase:
Follicle grows 2-6 years - Catagen phase:
Follicle stops growing and starts to involute at base - Telogen phase:
Hair is ready to fall out
How does pregnancy affect hair growth?
Estrogen and progesterone causes hair to stay in anagen phase longer (less hair loss)
Describe how one gets treatment to either curl (perm) or straighten hair
Hair has hydrogen and di-sulfied bonds. By breaking the di-sulfide bonds (stronger bonds) and reshaping them (replacing some H bonds) changes the structure of the hair.
What are the 3 layers of hair
Cuticle (outermost, dead cells)
Cortex
Medulla (center)
What are the differences between temporary, semi-permanent, permanent hair dyes?
Which layer of the hair is dyed.
ex. temp coats only the cuticle, semi-permanent dyes some of the cortex too
How does minoxidil work?
Increases follicular size, prolongs anagen phase of hair
How does finasteride work?
Alters 5alpha-reductase (which converts testosterone into DHT/dihydrotestosterone) preventing conversion of testosterone to DHT.
DHT normally acts in hairs causing baldness
How does fluoride act on teeth?
Strengthens mineral lattice of teeth, prevents bacterial erosion.
What does fluoride overdose do?
Causes fluorosis, causing discoloration in teeth.
Describe 2 types of gum disease
Periodontal disease:
Bacteria growth around the teeth, loosening the base
Gingivitis:
Inflammation of gingiva
How can gum disease be treated
Use of mouthwash and/or toothpaste with phenols (phenols interfere with bacteria growth and activity)
