L18 Drugs/Cosmetics Flashcards
What is minoxidil
the first cosmeceutical for male pattern baldness
increases follicular size and anagen growth phase
women can also use (OTC)
TF: Fluoride is a drug and cosmetic
True, although it prevents tooth decay and gum disease by getting rid of microorganisms, it is also used to keep our teeth looking nice
TF: All skincare creams are considered drugs
False, some are not while others contain compounds that are classified as drugs
Why must we be careful about compounds we put on babies?
Babies have high surface to volume ratio for skin
Describe the structure of the skin
Epidermis
Dermis
Hypodermis (superficial fascia)
Describe the epidermis
outermost layer of the skin (superficial layer)
No vasculature
Hair above epidermis is comprised of dead cells
Describe the dermis
Contains the blood vessels, hair follicles, various glans (sweat and sebaceous), muscle (goose bumps), and nerve endings
What are the roles for 1. sebaceous glands and 2. nerve endings
- sebaceous glands: located besides the hair follicle, it secretes sebum which lubricates the surface of the sin
- nerve endings: they are connected to sensory receptors to sense touch, pain, and temperature
What is the main element that distinguishes the skins of different individuals
chemical structure of melanin in the skin
How are melanocytes and keratinocytes related to melanin?
melanocytes produce melanin (pigment granules) and insert it into keratinocytes via extensions
How does sunburn affect melanocytes
melanocytes increase production (increased activity due to UV light) and insertion of melanin resulting in injury (sunburn) and darker skin colour
TF: sunburn is a reaction to UV injury
True
Why does the skin produce more melanin when exposed to UV light?
UV light increases melanocyte activity thus producing more melanin
This is because melanin works to block UV light
What makes tattoos permanent?
macrophages in the dermis layer uptake the pigment
when these macrophages die, surrounding macrophages uptake the ink they release
Name 5 kinds of sensory receptors in the skin
cold, heat, pain, touch, pressure
Why are superficial cuts and burns healed with no scars?
Skin cells have a fast turnover so it can continuously repair itself and repair deficits
TF: skin structure is the same all over the body?
False
skin behind ears is thin while skin on palms or soles are thick
TF: The number and types of glands is the same in every individual
False, it varies between individuals
Why are motion sickness patches applied behind the ears or on the abdomen
the skin is thinner there, allowing for better absorption and systemic distribution of the drug
TF: most people only have skin problems once they reach adolescence
True
What is psoriasis
It is characterized by patches of abnormal skin, skin turnover is very rapid causing skin to become thicker and cells that rise to the surface to flake off (increase skin cell synthesis)
Psoriasis cases are increasing
What is the general cause for photosensitivity?
allergic reaction to certain drugs
What kinds of drugs can cause photosensitivity
antibiotics, diuretics, antipsychotics, NSAIDS, plant and herbal mixtures/remedies, retinoids
Why must sunscreen be used on cloudy days?
80% of sun rays get through light clouds, mist, fog
TF: tanning is safe if it is done sparsely
False, tanning is a reaction to injury and is not safe
tanning increases the risks of cancer and causes wrinkles
What is UV light made up of? What does this mean for the skin?
UVA and UVB (290-400 nm range)
Since they have different wavelengths, this causes them to penetrate the skin at different extents
Which penetrates the skin deeper: UVA or UVB
UVA (400nm)
TF: UVA exposure is greater than UVB exposure
False, UVB exposure is greater
TF: Only UVB causes skin damager
False, UVA can also cause injury
TF: UV damage can causes cataracts
True
TF: tanning can increase the risk of melanoma (deadliest skin cancer) by 59%
True
Why are people with freckles particularly vulnerable to UV light
There is very little pigment between the freckles thus there is less protection against UV light
What is the biggest risk of sunburn?
The variable types of skin cancer (3)
basal cell carcinoma: can be removed before carcinoma becomes larger
squamous cell carcinoma
melanoma: lethal
UV light damage includes…
premature wrinkling, broken blood vessels, pigment changes, blotches in the skin, skin cancer
What does SPF stand for?
Sun protective factors
it is a measure of efficacy used to compare potency between different sunblocks
A 30 SPF sunscreen would provide 30 times the protection of no sunscreen
Why are individuals with lighter skin more prone to sunburn
they have less melanin, thus less protection against UV rays
What does broad-spectrum sunscreen mean?
It means it blocks both UVA and UVB
What is the minimum SPF in the winter? summer?
winter: 15
summer: 30
TF: UV exposure is greater in water and snow
True
water an snow can reflect UV light (snow can reflect up to 85%) thus increasing UV exposure
What are retinoids used for?
acne
+cancer and psoriasis
What problems can occur in acne? (4)
- occlusion of pilosebaceous duct where hair follicles normally come out form
- bacterial colonization in the duct, releasing inflammatory mediators
- increased sebum secretion (during adolescence usually), sebum lubricates hair shaft, hair, scalp, skin
- inflamed sebaceous gland: comedy may rupture and release contents into dermis in severe cases
what are the different stages of acne (abnormal keratinocytes)?
A. normal hair follicle
B. Oxidized sebum (mild hyperkeratosis/acne)
- blocking the duct caused sebum to accumulate, sebum at the open end oxidizes to form blackheads
C. trapped sebum (mild hyperkeratosis/acne)
- sebum trap below the surface of the skin forms whiteheads which contains bacteria and leukocytes. Close comedo
D. Bacteria and leukocytes (severe hyperkeratosis/acne)
- bacteria accumulates in sebum which attracts WBC/leukocytes. Rupture of the comedo causes inflammation and spread
- both blackheads and whiteheads (open and close comedo) can accumulate bacteria and increase sebum accumulation
TF: Cystic/nodule acne contains sebum, bacteria and leukocytes
True
Describe cystic acne
It is characterized by long and deep nodules and presence of cysts
It is usually treated before it gets to extreme levels of severity
Like a papule/pustule but worse
TF: There are no animal models for acne
True
TF: Androgens decrease sebum secretion
False, androgens (especially testosterone) increase sebum production
What are the 4 hallmarks of acne
increased sebum, increased keratin, increased bacteria, inflammation
What are the 4 targets to reduce acne
- normalize follicular keratinization
- too much keratinization during acne (comedogenesis)
- topical retinoids, accutane - reduce bacteria, antibiotics topically or systemically
- gets rid of infection and inflammation
- benzoyl peroxide, antibiotics
- retinoids have indirect antibacterial effect
3 inhibit sebaceous gland function
- sebum is a medium for bacterial growth, it also blocks the duct
- accutane, hormonal therapy, corticosteroids
- retinoids
- contraceptives for mild acne
- decreased inflammation
- corticosteroids, NSAIDS, antibiotics, retinoids (useful for all 4)
What kinds of drugs can you use for acne? (6)
Retinoids (topical or systemic e.g. accutane)
antibiotics, benzoyl peroxide
hormonal therapy
contraceptives
corticosteroids
NSAIDS
What effects do we look for in drugs for acne?
- normalize comedogenesis (regulate keratinocyte turnover)
- inhibit sebaceous gland function
- antibacterials
- anti-inflammatory
Why are retinoids such as tretinoin and isotretinoin so powerful in treating acne
they attack multiple targets
What are some drugs that normalize comedogenesis
tretinoin (retinoid), benzoyl peroxide, isotretinoin (retinoid), sulfur, azelaic acid
What are some drugs that can inhibit sebaceous gland function/decrease sebum production
antiandrogens (spironolactone), corticosteroids (oral, in low doses), estrogen (oral contraceptives), isotretinoin (indirect effect)
What are some drugs with antibacterial effects
antibiotics, isotretinoin (retinoid), benzoyl peroxide (local)
what are some drugs with anti-inflammatory effects
NSAID (affect sebaceous gland), antibiotics (prevent neutrophil chemotaxis), corticosteroids, retinoids
Why are retinoids useful for acne
- normalize comedogenesis
- antibacterial
- anti-inflammatory
Why is benzoyl peroxide useful for acne
- normalize comedogenesis
- antibacterial
Why are sulfur and azelaic acid useful for acne
they normalize comedogenesis
Why is hormonal therapy using antiandrogens (spirolactone), corticosteroids, estrogen useful for acne
it inhibits sebum production
Why are corticosteroids useful for acne
- decrease sebum production
- anti-inflammatory
TF: Retinoids are Vitamin D derivatives
False, vitamin A derivatives
Vitamin A is a generic term for…
retinol, retinaldehyde, retinoid acid, retinoids, and related compounds
TF: Retinoids act as hormones and alter gene expression
True
What cellular process do retinoids have a major role in?
cellular differentiation
TF: Synthetic retinoids are mostly non-aromatic compounds
False, they are mostly aromatic
What differentiates third generation retinoids from previous generations?
They are more selective and less toxic
What are some very effective retinoids
tretinoin and adapalene (Differin)
TF: Isotretinoin is an OTC
False, it requires a prescription
What are retinoids used for other than acne?
psoriasis, cancer
drugs that block receptors are very useful
TF: Retinol is freely transported through the body as it is water-soluble
False, it is not water soluble. It needs to be bound to the “retinol binding protein” for movement
TF: both the retinol and RBP bind to the retinoid receptor and enter the cell
False, only the retinal binds and enters the cell. The RBP dissociates
What happens once retinol enters the cell?
Retinol is bound by cellular RBP and then converted to retinaldehyde, then retinoic acid by enzymes in the cytoplasm
How can retinol affect gene expression (pharmacodynamics at a molecular level)
- retinoid acid binds to retinoid acid binding protein to be taken to nucleus
- 2 molecules of retinoid acid bind to RAR ad RxR receptors on the nucleus causing their dimerization (heterodimer)
- dimerization causes retinoid acid response element to alter gene expression
RAR (retinoid acid receptors) and RxR (retinoid X receptor) are in which receptor family?
nuclear hormone receptor family
TF: trans retinoid binds to RXR and cis retinoid binds to RAR
false
trans - RAR
cis - RXR
TF: RXR has subtypes the includes isoforms alpha, beta, delta
False, RAR has subtypes (alpha, beta, gamma)
RXR has 1 subtype (alpha)
What are factors that determine whether the binding to nuclear hormonal retinoid receptors RAR and RXR increase or decrease gene expression
cell type
combination of dimer
agonist
Change in gene expression triggered by retinoids can lead to…
- decrease in sebum production/decrease in keratinocyte activity
- decrease in inflammation w/ antibacterial effect
- change in sebum composition (does not foster bacteria anymore)
overall decrease in acne
TF: retinoids are teratogens only at high doses
False, they are teratogens even at low doses
Can affect 1st month of pregnancy
What makes retinoids teratogenic?
Retinoids play a huge role in cell differentiation which can affect fetus development
What can retinoids cause in fetus?
malformations in face (skull, ears, jaws), kidneys, heart
psychological and intellectual development also affected
TF: Retinoids may cause GI disorders
True
Can retinoids cause inflammatory bowel disease
Yes
Interaction of retinoid with what kind of drug can cause possible GI distress?
NSAIDS
TF: Antibacterial soap for washing faces is necessary for clear skin
False, humans have natural bacteria present in their follicles
How does soap reduce transmission of colds?
it gets rid of superficial bacteria and viruses which can be transmitted
TF: Moisturizers can repair the skin
False, they lubricate skin but do not repair it
TF: Moisturizer prevents aging
False, only sunblock can prevent aging (or the signs of aging)
What is skin cream a mix of?
water, powder (active ingredient), grease/oil (for application)
TF: humans can absorb collagen and elastin through epidermis
False, epidermis is impermeable to collagen and elastin
What do advertisements include to convince you to buy an acne products
- attractive people
- doctor-approved signature
- scientific information
TF: moisturizers can fix cellulite
False,
moisturizer can only penetrate skin at its surface level while cellulite occurs at deeper levels
Most ingredients in cosmeceuticals are… (3)
preservatives (stop microbial growth), fragrances, surfactants
What makes cosmeceuticals potentially toxic?
- trace metals
(transdermal absorption increase due to damaged skin barrier) - phthalates
- parabens
What are phthalates and why are they dangerous
perfumes, lotions, nail polish, hair care
carcinogenic at high doses, endocrine disruptors, reproductive system disruptors, immunotoxicity, allergies, lowers sperm count
Why are parabens dangerous
they can disrupt the immune system
What causes cold sores?
herpes virus (DNA virus) HSV-1
- herpes nests in nerve endings of trigeminal ganglions
- it can then be triggered by stress, disease, etc. where it does through the nerve and causes a lesion
- immune system keeps it contained
Why is it problematic if you are immunocompromised if you have cold sore herpes
immune system is what keeps it contained within the mouth area/trigeminal ganglion
without it, it could spread and make it worse
Which drug is very effective against HSV-1? What does it do
Acyclovir
inhibits viral proliferation
What is acycloGTP and what does it do
it is a phosphorylated and activated form of acyclovir
It inhibits viral DNA polymerase, may also cause chain termination
How much hair do we have
5 million hairs
100 000 on head
At what rate does hair grow
6 in / year
TF: hair can grow infinitely long
False, hair usually only grows for a certain amount of time until it falls out
max is usually 3 ft
What inserts pigment into hairs?
melanocytes
What are the different layers of a hair
cuticle (outer, dead cells)
cortex (inner)
medulla (core)
Where are the live cells located in hair
base of follicles under the surface of the skin (in the matrix)
TF: There are stem cells located on the side of hair shafts
True
Why are there stem cells on the side of hair shafts
to initiate growth of new follicles after the old one falls out
In which layer of the hair is keratin located
Cortex
What is the composition of hair cortex
Keratin
protofibrils make up microfibrils which make up macrofibrils which are packed together in the cortex
What factors can affect the hairs ability to retain moisture
hair texture
humidity (more humid = more curly)
heat drying
Describe the hair growth cycle
- ‘bulge’ stem cells turnover and create new hair
- anagen active growth phase: follicle grows for 2-6 years
- Catagen/transition phase: 1-2 weeks, hair stops growing and starts to involute (fold inward) at base
- Telogen/resting phase: hair is ready to fall out
TF: beard growth increase in july
True
TF: Scalp hair sheds in winter
false, It sheds in summer
How do hormones alter hair growth?
estrogen and progesterone retains hair in anagen phase (during pregnancy)
hair goes into telogen phase after pregnancy is over so that all the hair that was supposed to be lost is shed + a few more
What can damage hair?
heat, brushing (back combing/teasing), chlorine, bleach
lacquer doesn’t damage hair as it stays on the surface and can be washed off
+UV damage
What cause hair to be curly?
They have more hydrogen and disulphide bonds
*curly hair has more of both, and its important to keep curly hair moisturized for well-defined curls ;)
Describe the order of compounds that lead to hair pigment
tyrosine -> dopa -> dopaquinone -> eumelanin or pheomelanin
TF: modifications to tyrosine is the reason behind the variety of hair colours we see in different individuals
True
What causes hair bleaching
sun (UV damage) and peroxide can damage melanin i.e. structural shift and a change in refraction of light and colour
What makes a hair dye permanent?
It penetrates into the cortex
To do so, chemical structure of hair must be disrupted
TF: bleach can cause cuticles to raise
True
How much hair do we lose per day
50-100
What are terminal hairs replaced by in male baldness?
villus (soft and thin little hairs)
Replaced and there are less of them
What makes male and female baldness different?
female baldness is only the thinning of the hair rather than the loss of hair
What is a drug that can be used to treat baldness? How does it work
Rogaine minoxidil: increases follicular size and prolongs the anagen growth phase of hair
+Finesteride and Dutasteride (alpha-reductase inhibitor, decrease DHT)
TF: Susceptibility to hair loss is the same at all part of the head
False
What is Finasteride (Propecia)? What does it do
it is used to treat baldness (more effective than minoxidil) systemically
More efficient when used before baldness becomes extensive
It inhibits the 5-reductase (which converts T to DHT) thus preventing bladness (DHT is more potent than T in its ability to make people bald lol)
How does DHT cause baldness
it acts not he nucleus of follicles to cause changes
TF: Finasteride (propecia) is teratogenic for male fetuses
True
Finasteride is used to treat hair loss in men
TF: Dutasteride is used to treat acne
False, it is used to treat baldness as it inhibit 5-reductase i.e. DHT synthesis
What are 2 hair damage products that work? How do they work
olaplex and K18 (peptide with 18 amino acids)
olaplaex: repairs damaged keratin (repairs broken disulphide bonds) by making an ionic bond and inserting itself between 2 keratin molecules
K18: relinks broken keratin strands
What is fluoride used for
prevention of cavities and gingivitis
When are primary teeth formed?
in utero
Taking which drug during pregnancy can cause tooth discolouration in baby?
tetracycline (accumulate in teeth causing discolouration)
TF: toothpaste contains abrasive compounds for whitening
True
Which drug can cause gingival hyperplasia i.e. growth of gums over teeth?
phenytoin (drug to treat seizures)
TF: fluoride is antimicrobial
true
What makes fluoride antimicrobial
it strengthens the mineral lattice of the teeth (remineralization), defending against bacterial erosion
What causes white spots on teeth?
mild floride overdose (fluorosis)
TF: 1/2 people have gum disease
False, 3/4 people have gum disease
What is periodontal disease
it is a disease that makes teeth susceptible to bacterial growth causing problems for the gums and loosening the teeth
What is gingivitis
inflammation of gingiva (gums)
red swollen gums that bleed easily
How do you treat gingivitis
mouthwash or toothpaste with phenols
phenol interferes with bacteria that cause gingivitis
