Transcript Mechanism of Action

Dermatotherapeutics - Topical
Digital Lecture Series : Chapter 30
Dr. Pallavi Utekar-Telavane
Assistant Professor,
Department of Dermatology,
Rajiv Gandhi Medical College and
Chatrapati Shivaji Maharaj Hospital, Thane
CONTENTS
 Introduction
 Cytotoxic and Immunomodulatory
 Drug delivery
 Keratolytic agents
 Patient information
 Moisturizers
 Steroids
 Sunscreen
 Anti acne
 Depigmenting agents
 Anti-bacterial
 Anaesthetic
 Anti-fungal
 Miscellaneous
 Anti-viral
 MCQs
 Anti-parasitic
 Photo Quiz
 Calcineurin inhibitors
Introduction
 Topical therapy implies delivery of medicines at the site of the lesion
 It’s a mainstay of treatment in most dermatological disorders.
 While prescribing topical agent to the patient a physician must
consider the product itself , the disease to be treated and the patient.
Advantages and disadvantages of Topical Therapy
Advantages
Disadvantages
Reduced systemic side effects
Requires lots of counselling
Accessibility & visibility of the
therapy on skin
Expected results might not be
achieved due to lack of compliance
Few medicines which cant be used
systemically can be used topically
e.g. salicylic acid
Allergic reactions can be noted not
because of drug but because of
vehicle as well
Penetration of molecule is affected
by multiple factors which can affect
the desired results
Factors affecting drug delivery
 Age of patient: Absorption is more in neonates and children as
compared to adults
 Traumatised or diseased skin allows easier penetration
 Site of application : Absorption is better in the following sites in
descending order : mucous membrane, scrotum, eyelids, face, chest
& back, upper arms & thighs, lower arms & legs, dorsa of hands &
feet, palmar & plantar skin followed by nails.
 Potency : Higher the concentration of the drug in the topical
formulation better is the absorption and therapeutic effect.
 Vehicle used : Ointments have better penetration than creams,
lotions, gels or pastes
Factors affecting drug delivery
 Occlusion : increases hydration and temperature of stratum
corneum, thus increasing penetration of the drug.
 Hydration: Simple immersion in water for 5 min prior to application
of topical agent increases absorption.
 Frequency of application : doesn’t significantly increases
effectiveness of molecule except that for emollients.
 Quantity of drug applied has negligible effect on absorption.
 Massaging: vigorous rubbing or massaging increases the
penetration.
 Presence of hair follicles : enhances drug penetration.
Vehicle
Vehicle is the substance which brings the topical medication in contact
with the skin.
Types of vehicles :
 Liquids : Solutions , Lotions, Liniments, Suspensions
 Semisolids : Creams, ointments, Pastes, Gels
 Solids : Powders
Liquids
Solutions :
 Wet dressings : These are of 2 types Open and Closed dressings.
Solutions of choice are Normal saline, burrow’s solution, Condy’s
compresses etc.
 Bath : method used when a part or all of the body has to be treated
e.g. 8-MOP bath.
 Tinctures and Paints : these are liquid preparations which are applied
over skin or mucous membrane with a brush and left to evaporate.
Liquids
Lotions :
These are liquid or semisolid preparations and consist of solutions of
drug in water, alcohol or other liquids. On evaporation drug is deposited
on skin surface.
Liniments :
These are non aqueous solutions of drugs in oil or alcoholic solutions of
soap.
Poultices :
These are wet solid masses of particles, sometimes heated, that are
applied to diseased skin. These are used as cleansers and absorptive
agents in chronic exudative lesions such as leg ulcers.
Semisolids
Creams : These are semisolid emulsions containing two immiscible
liquids (suspension of water and oil). There are of 2 types:
 Oil in water type (O/W)
 Water in oil (W/O)
Ointments :
These are semi-solid, soft to firm, greasy preparations that carry active
ingredients in concentration of up to 40%.
They are occlusive and act as emollients.
Semisolids
Pastes : These are semisolid preparations of finely powdered material in a
greasy base, in approximately 1: 1 ratio.
Pastes protect the skin from mechanical forces, absorb moisture and aid
drying of oozing and weeping lesions.
Gels : Gels are soft, semisolid preparations, translucent to transparent in
appearance, that liquefy on contact with the skin and dry as thin, greaseless
films.
Solids
Powders :
Powders are solid preparations used to promote drying or reduce friction.
Newer Drug Delivery System
 Nanotechnology :
•
Solid or liquid lipid nanoparticles act as carriers.
•
Drugs are entrapped within lipid core matrix.
•
It improves cutaneous bioavailability as it has ability to penetrate
follicles.
 Microemulsions :
•
This is a thermodynamically stable mixture of oil and water
stabilized by surfactants.
•
Can solubilize many poorly soluble drugs.
Newer Drug Delivery System
 Liposomes :
•
These are vesicles which consist of one or more concentric lipid
bilayers separated by aqueous buffer compartment.
•
These either get adsorbed over skin and release the drugs or
penetrate via lipid rich channels.
 Microsponges :
•
These have porous beads which encloses the active drug.
•
Cosmetically better acceptance.
Instruction provided to patients






Frequency of application.
Timing of application.
Quantity for every application.
Common side effects seen with the medication.
Total duration of use.
Not to self-treat.
Quantity of application
It is described in terms of Finger Tip Unit and Hand areas.
 Finger Tip Unit (FTU) : If a cream or ointment is squeezed out of a tube
which has a nozzle of 5mm, over the distal section of an index finger from
distal skin crease to tip of finger, the amount is roughly equal to 0.5g.
Quantity of application
Site for an adult
Quantity in FTU
No. of Hand Areas
Face and Neck
2.5
5
Front and Back of Trunk 14
28
One arm
4
8
One hand
1
2
One leg
8
16
One foot
2
4
Topical Steroids
Mechanism of Action
It acts by binding to specific DNA sequence i.e. Glucocorticoid responsive
elements (GRES) and transcription of specific mRNA.
 Anti-inflammatory
 Immunosuppressive
 Anti-proliferative
 Vasoconstriction
Potency ranking of topical corticosteroids
Class 1 (Super potent)
Halobetasone Propionate (0.05%)
Clobetasol propionate (0.05%)
Class 2 (Potent)
Mometasone Furoate oint (0.1%)
Betamethasone dipropionate (0.05%)
Class 3 (Potent)
Fluticasone Propionate (0.005%) oint
Class 4 (Mid-strength)
Mometasone Furoate cream (0.1%)
Triamcinolone Acetonide oint (0.1%)
Potency ranking of topical corticosteroids
Class 5 (Mid strength)
Fluticasone Propionate cream (0.05%)
Hydrocortisone Butyrate (0.1%)
Class 6 (Mild)
Desonide (0.05%)
Fluocinolone Acetonide cream (0.01%)
Class 7 (Least potent)
Dexamethasone cream (0.1%)
Hydrocortisone (0.5%,1%, 2.5%)
Intralesional corticosteroids
 When topical applications are ineffective, few
preparations can be directly injected into the
skin lesion.
 Preferred agent : Triamcinolone acetonide.
 Properties : Long acting, small particle size,
stable at room temperature, Easy resuspension
by shaking, lesser effects on pituitary- adrenal
axis.
 Indications : Nodulocystic acne, keloid,
hypertrophic scar, prurigo nodularis, etc.
Nodulocystic Acne
Indication









Eczematous disorders
Papulosquomous disorders – Psoriasis, Lichen planus, etc.
Bullous dermatoses
Connective tissue
Neutrophilic dermatoses
Alopecia
Insect bite reaction
Photodermatoses
Pigmentary disorders – Vitiligo and many more…
Contraindications :
Absolute – h/o hypersensitivity to tropical corticosteroid.
Relative – Local untreated bact, fungal, viral, mycobact infection,
infestatation, ulceration.
Chronic Eczema
Psoriasis
Alopecia Areata
Lichen Planus
Side effects of Topical Steroids
Striae
Contact dermatitis
Telangiectasia
Tachyphylaxis
Stellate pseudoscars
Facial hypertrichosis
Hypopigmentation
Folliculitis
Fragile skin, purpura
Miliaria
Impaired wound healing
Increased susceptibility to bacterial
fungal and viral inf.
Steroid dependency
Perioral Dermatitis
Glaucoma and cataract
Rosacea
Atrophy
Topical Steroid induced
hypopigmentation
Topical steroid induced
hypopigmentation and telangiectasia
Topical steroid induced
telangiectasia
Topical steroid induced
perioral dermatitis
Intralesional steroid induced atrophy
Topical steroid induced atrophy
Tinea Incognito with striae
Acneiform Eruption
Acneiform Eruption with Hypertrichosis
Systemic side-effects of topical steroids
 Suppression of hypothalamic – pituitary – adrenal axis
 Cushing’s syndrome
 Hyperglycemia
 Intracranial hypertension
 Growth retardation in children
 Reduced bone mineral density
 Oedema
 Hypocalcemia
 Hypertension
Anti acne medicines
Class
Mechanism of Action
Retinoids :
 Block inflammatory
 Tretinoin cream
cascade
(0.025%- 0.05%)
 Decrease
 Adapalene gel (0.1%)
hyperproliferation in the
follicles
 Stimulate dermal collagen
production
Benzoyl peroxide
 Oxidising agent so direct
toxic action on P. Acne
 Lipophilic so penetrates
sebaceous follicles better
 No resistance has been
noted
Side Effects
 Causes irritation
 Are photo irritants
 Irritation,
erythema, scaling,
burning,
dryness,stinging
 Contact dermatitis
Anti acne medicines
Class
Mechanism of Action
Side Effects
Topical antibiotics
 Erythromycin (2%)
 Clindamycin (1%)
 Clarithromycin (1%)
 Azithromycin (2%)
 Nadifloxacin
 Dapsone (5%)
 Metronidazole gel
 Reduce population of P.
Acne
 Few have antiinflammatory action
 Should not be
used continuously
for 3 months for
the fear of
resistance
Azelaic Acid 10%-20%
 Antibacterial
 Anti-keratinizing effect
 Inhibit tyrosinase enzyme
 Irritation
Nicotinamide gel 4%
 Anti-inflammatory
 Not specific
Anti acne medicines
Class
Mechanism of Action
Side Effects
Salicylic Acid
 Keratolytic
 Inhibits comedogenesis
 Promote follicular
desquamation
 Lipid soluble so penetrate
sebum laden follicles
better
 Irritation,
erythema
Ivermectin gel ( used in
rosacea)
 Anti parasitic action on
Demodex folliculorum
Grade 2 Acne
Antibiotics
Name
Bacterial coverage
Mechanism of action
Bacitracin
Bactericidal against Gram
(+) and Neisseria species
Interferes with bacterial wall
synthesis; inhibition of
phospholipid receptors involved
in peptidoglycan synthesis
Polymyxin B
Bactericidal against Gram (-) Increases permeability of
bacteria only; effective
bacterial cell membrane; by
against P. aeruginosa
interacting with phospholipid
components of membrane
Neomycin
Bactericidal against Gram (+) Inhibits protein synthesis;
and Gram (-) bacteria; good binding to 30s subunit of
S. aureus coverage
ribosomal RNA
Antibiotics
Name
Bacterial coverage
Mechanism of action
Metronidaz Anaerobic bacteria,
ole (0.75parasites
1%)
Forming free radicals that
damages DNA ;
Immunomodulatory
Sodium
fusidate
(fusidic
acid) 2%
Interfere with bacterial
protein synthesis by
preventing translocation
of elongation factor G
from ribosome
Anti staphylococcal
Impetigo Contagiosa
Antibiotics
Name
Bacterial coverage
Mechanism of action
Mupirocin
Bactericidal against
methicillin-resistant
S. aureus; S. pyogenes
Inhibits bacterial RNA and
protein synthesis; occurs by
reversibly binding to bacterial
isoleucyl transfer RNA
synthetase
Retapamulin
Bacteriostatic against
S. pyogenes,
mupirocin-resistant and
methicillin-resistant
S. aureus, anaerobes
Inhibits bacterial protein
synthesis; occurs by binding to
protein L3 on 50s ribosomal
subunits
Antibiotics
Name
Bacterial coverage
Mechanism of action
Gentamicin
Bactericidal against Gram (+) Inhibits bacterial protein
and Gram (-) organisms;
synthesis; by irreversibly binding
coverage includes
to 30s ribosomal subunits
P. aeruginosa
Silver
sulfadiazine
Bactericidal against Gram (+) Binds to bacterial DNA and
and Gram (-) organisms
inhibits its replication
Antifungal Agents
Class and Prototypes
Spectrum of action
Azoles
Eg. Fluconazole, Ketoconazole,
Sertaconazole, Eberconazole ,etc.
(Fungistatic)
Dermatophytes, candida,
pityrosporum, erythrasma, some
action against staphylococcus
Allylamines
Eg. Terbinafine, naftifine
Dermatophytes (fungicidal), Candida
albicans (fungistatic)
Morpholines
Eg. Amrolfine
Onychomycosis caused by
dermatophytes, scytalidium
spp.,Scopularis spp.,dimorphic fungi,
C. Albicans, Cryptococcus neoformis,
dematiaceous fungi.
Antifungal Agents
Class and Prototypes
Spectrum of action
Benzylamines e.g. Butenafine
Dermatophyte (fungicidal), C. Albicans
(fungistatic), P. versicolor
Polyenes
Eg. Nystatin
Oral and Vaginal Candidiasis
Miscellaneous
1. Ciclopirox olamine
Dermatophytes, yeasts, molds e.g.
Scytalidium spp. Scopulariopsis spp.
2. Zinc pyrithione 1%
3. Selenium disulfide 2.5%
P. Versicolor
Sterol pathway in fungi and steps at which antifungal drug act.
Allylamines (terbinafine, naftifine)
Benzylamines (butenafine)
Tolnaftale
Acetyl
coenzyme A
Squalene
Squalene epoxide
Squalene epoxidase
Triazoles (fluconazole, itraconazole)
Imidazoles (ketoconazole)
Lanosterol
14 α Demethylase
14 α Dimethyl
Lanosterol
Amorolfine
Zymosterol
δ14-Reductasee
Amorolfine
Fecosterol
Episterol
δ7 δ8 Isomerase
Amphotericin B
Fungal cell membrane
synthesis
Griseofulvin
Fungal cell replication
Ergosterol
Antivirals
Agent
Indications
Acylovir (5%) cream
Herpes labialis, herpes genitalis
Penciclovir (1%) cream
Herpes labialis, herpes genitalis
(longer duration of activity)
Cidofovir
Human papilloma virus, herpes and
pox virus infections, Useful in HIV
positive patients
Foscarnet
In acyclovir resistant cases
Idoxuridine
Herpes simplex, herpes zoster,
human papilloma virus infections
Topical and intralesional antiviral agents
Viricidal
Cytodestructive
Immune Enhancer
Acylovir
Bleomycin
Imiquimod
Penciclovir
Podophyllin
Inteferon
Cidofovir
Trichloroacetic acid
Foscarnet
Cantharidin
Idoxuridine
Salicylic acid
5-Fluorouracil
Herpes simplex
Antiparasitic agents
Agent
Mechanism of Action
Side effects
Permethrin
(5% cream and 1%
lotion)
Acts on nerve cell
membranes of the
parasite causing paralysis
and death.
Burning, Itching,
Numbness, stinging,
tingling,
Hypersensitivity
Gamma-benzene
Hexachloride
(1% lotion)
CNS excitation,
Inhibit inositol to produce
agitation, delirium,
CNS excitation
convulsions etc.
Benzyl benzoate
(25% emulsion)
Not known
Pruritus, redness, ACD,
Seizures
Malathion
(0.5% lotion)
Cholinesterase inhibition
in a parasite
Irritation to skin
Antiparasitic agents
Agent
Mechanism of Action
Side effects
Crotamiton
(10% solution)
Not known
Pruritus, swelling,
redness
Precipitated sulfur
(6% lotion)
Kills the mite by unknown Hypersensitivity to
mechanism
sulfur
Ivermectin
(1% cream and
shampoo)
GABA-nergic action to
block chloride channels
Nil
and causes tonic paralysis
Scabies
Calcineurin Inhibitors
Prototypes :
 Tacrolimus (FK 506), Pimecrolimus
Mechanism of Action :
 Immunosuppression - by inhibiting proliferation and activation of
CD4+ T Helper cells by inhibition of cytoplasmic enzyme calcineurin.
 Immunomodulation - by inhibition of mast cell adhesion and
inhibition of mediators release from mast cells and basophils.
 Release of local neuropeptides and transmission of pain and itch.
 On Keratinocytes- increase stem cell factor release which causes
proliferation of melanoblasts and melanocytes.
Side Effects :
 Local burning, Pruritus, Infections, Risk of malignancy (Black Box
Warning)
Calcineurin Inhibitors
Indications
Contraindications
Eczemas, Atopic Dermatitis
Pregnancy
Vitiligo
Infected lesions
Facial and flexural psoriasis
Prolonged exposure to sunlight
Oral and Genital lichen Planus, Lichen
Conditions causing breach in skin
striatus, Lichen sclerosus et
barrier properties
atrophicus
Morphea, lupus
erythematosus,Bullous disorders
H/o contact sensitization
Steroid induced Rosacea, Chronic
actinic dermatitis
Pimecrolimus cream should not be
applied to mucous membrane or
eyes
Cytotoxic and Immunomodulatory agents
Imiquimod - 5% cream
 Mechanism of action
Trigger immune system to recognize the presence of a vital infection or
tumor and mounts Th1 weighted cellular immune response.
 Application : 3 times a week ( 6-10 hrs ) for 8 – 12 weeks.
 Indication : General warts, Actinic Keratoses, Molluscum
contagiosum, intraepithelial neoplasia, Bowenoid papulosis,
verrucous carcinoma, SCC etc.
 Side effects :
 Local : Erythema, irritation.
 Systemic : Fatigue, fever, myalgia, central and peripheral nervous
system disorder, Influenza like symptoms
Cytotoxic Agents
Agent
Mechanism of
Action
Indication
Bleomycin
Binds to DNA

causing cell to
accumulate in G2 
phase

5-Fluorouracil
Antimetabolite to
uracil thus block
synthesis of DNA
in hyper
proliferative
keratinocytes
Intralesional
injection
Keratoacanthom
a
Recalcitrant
warts
Genital warts
Actinic keratosis,
BCC, bowenoid
papulosis,
erythroplasia of
queyrat,
leukoplakia, etc.
Side effects
Pain swelling Raynaud’s ph.
syst
Myelosuppression
Pulm fibrosis, hyperthermia,
hypotension
Local - erythema, crusting,
scaling, pain, swelling, pruritus
hyper and hypo pigmentation
photosensitivity
Systemic - Stomatitis,
myelosuppression cardiac
toxicity, alopecia, etc.
Keratolytic Agents
 Used to treat hyperkeratosis
 These break cell to cell adhesions, thus help to remove scales
 Few of these have hydrating effect, thus used as moisturisers
 Few have anti-inflammatory, anti-ageing effect
 e.g. Salicylic acid, urea, alpha hydroxy acids such as glycolic acid,
lactic acid, coal tar etc.
Moisturizers
 Moisturizers hydrate the skin.
 Classification : Emollients and Humectants
Emollients :
These are greasy substances, which hydrate stratum corneum by forming a
greasy layer over the skin surface, thereby preventing transepidermal water
loss and retaining moisture in the skin.
E.g. Liquid paraffin, almond oil etc.
Humectants:
Humectants are the substances which hydrate stratum corneum by
absorbing water from the external environment or from deeper layers of the
skin.
E.g. Glycerin, urea, lactic acid and sodium lactate etc.
Sunscreen
Protects skin from Ultraviolet radiations
 Sun Protection Factor (SPF) :
Minimal erythema dose of UVB light with sunscreen applied
Minimal erythema dose of UVB light without sunscreen
 Broad spectrum protection :
Full spectrum UVB/UVA protection
 Water resistant sunscreen :
SPF maintained after 40 minutes of water immersion
 Waterproof sunscreen :
SPF maintained after 80 minutes of water immersion
Sunscreen
 Ingredients in sunscreen
UVB blockers
Octinoxate
Octisalate
UVA blockers
Avobenzone
Oxybenzone
Physical Blockers
Titanium dioxide
Zinc oxide
Sunscreen
Methods of Application :
 Quantity required is 2g/cm2
 30 min before exposure to sunlight
 Reapplication after every 3-4 hours
 Reapplication after swimming or sweating
Indications :
 Photodermatoses e.g. polymorphic light eruption
 Photosensitive eruptions, rosacea , etc.
 Systemic Lupus Erythematosus
 Xeroderma pigmentosum
Depigmenting Agents
Agent
Mechanism of Action
Side effects
Hydroquinone
[2% - 5%]






Inhibiting tyrosinase
thus inhibiting
conversion of dopa to
melanin
Alteration of
melanosome function
Generation of ROS


ICD and ACD
Nail discoloration
Paradoxical PIH and
surrounding
hypopigmentation
Exogenous ochronosis
Permanent depigmentation
Depigmenting Agents
Agent
Mechanism of Action
Monobenzyl ether Cytotoxic action on
of hydroquinone
melanocytes
20%
[Residual
pigmented areas in
residual vitiligo]
Retinoids
Tretinoin 0.05%
Adapalene 0.1%




Induced dispersion of
keratinocyte pigment
granules
Interference with
pigment transfer
Acceleration of
epidermal turnover
Induce desquamation
Side effects






Permanent depigmentation
Depigmentation at sites
other than those being
treated
Contact dermatitis
Erythema
Peeling in areas of
application
PIH
Depigmenting Agents
Agent
Mechanism of Action
Azelaic Acid
(9-carbondicarboxylic acid
isolated from
cultures of P.ovale)
10% and 20%


Kojic acid
(Fungal metabolite
derived from
acetobacter ,
aspergillus
Penicillium)
1% - 4%
Inhibit Tyrosinase
Side effects
ROS Scavenger capacity Burning, stinging, itching
Alteration of
hypopigmentation
mitochondrial
hypertrichosis
metabolism
Contact dermatitis, Stinging
erythema
Depigmenting Agents
Agent
Mechanism of Action
Side effects
a - Hydroxy Acids
Glycolic - 5% - 20%
Lactic - 8% - 12%


Inhibit tyrosinase
Accelerate turnover of
stratum corneum
Mild irritation, burning
sensation.
Ascorbic acid


Antioxidant
Interaction with copper
ions at tyrosinase
active site
Reduce Dopaquinone

Liquorice extract
e.g. Glabridin


Decrease tyrosinase
activity
Inhibit UVB induced
skin pigmentation
Mild irritation
Depigmenting Agents
Agent
Mechanism of Action
Side effects
Arbutin
B-Glycoside of
hydroquinone


In higher concentration greater
risk for paradoxical
hyperpigmentation
Niacinamide
(derivative of
niacin)
Inhibits melanosome
transfer from melanocytes
to keratinocytes
Inhibit tyrosinase
Inhibit melanosome
maturation
Common Indications
 Melasma, solar lentiginosis post inflammatory hyperpigmentation
 Most of these agents work best in combination
 Kligmann’s formula – This is a triple formula being used or melasma
(4% hydroquinone, 0.1% tretinoin and 0.1 % Dexamethasone)
Melasma
Topical Anaesthetic Agents
Analgesic
Indication
Side effects
Capsaicin
Acts by exhaustion of
substance P after
repeated application
Post herpetic neuralgia
pain
Redness, burning
sensation
EMLA
( Eutectic Mixture of Local
Anaesthetic creams)
50% lidocaine and 50%
prilocaine in an oil in
water emulsion
Multiple small skin
procedures e.g. Needling
and extraction,
Dermatosurgeries e.g.
Radiocautery, dermaroller
therapy
Transient skin blanching,
erythema, urticaria,
Allergic contact
dermatitis, Irritant
contact dermatitis,
purpura,
hyperpigmentation
Miscellaneous
Vitamin D derivatives (Calcipotriol) :
 Inhibits epidermal proliferation, induces differentiation and has anti-
inflammatory effects.
 Indications : Psoriasis, Morphea, etc.
Anthralin :
 Synthetic derivative of Chrysarobin.
 Affects DNA synthesis and thus reduces keratinocyte proliferation.
 Used as short contact therapy (5-10min).
 Indication : Psoriasis.
Miscellaneous
Coal Tar :
 By-product of petroleum distillation.
 Suppresses DNA synthesis in keratinocytes thus decreasing their
proliferation.
 Side effects : folliculitis, acne, allergic sensitization, staining of clothes
and phototoxicity.
Miscellaneous
Antipruritic :
 Doxepin 5% cream
H1 and H2 receptors,adrenergic, muscarinic receptor antagonism
 Menthol – upto 16%
Agonist of thermally sensitive receptor, gives cooling sensation
 Phenol low concentration (0.5 - 2%)
Acts through its anaesthetic effect.
Soothing agent :
It reduces itching burning and discomfort of skin. e.g. Calamine lotion.
Anti – perspirants
 Aluminium chloride hexahydrate , Formaldehyde soaks, Botulinum toxin
injections.
Miscellaneous
Astringents :
These are compounds used to reduce exudation.
Mechanism of action :
 Coagulating proteins
 Coagulated proteins forms a protective coat
 Reduces oozing
Examples :
 Potasium Permaganate - 1:4000 to
1:25,000 Condy’s compresses
 Aluminium acetate ( 1:10 to 1:40 ) ( Burow’s Solution )
 Silver Nitrate ( 0.1% - 0.5% )
Miscellaneous
Minoxidil :
Mechanism of action :
 Vasodilator by opening potassium channel
 Increases duration of anagen phase
 Converts vellus hairs into terminal hairs
Uses:
Androgenetic alopecia, alopecia areata, Female pattern baldness
Available as 2%, 5%, 10% solution, gel, foam.
Miscellaneous
Topical contact allergens
Mechanism of action :
 Antigen competition: Immune reaction to one antigen may inhibit
the development of immune response to another unrelated antigen.
 Also can stimulate cell mediated cell response in viral infections
Agents :
 Diphenylcyclopropenone
 Squaric acid dibutyl ester (SADBE)
 Dinitrochlorobenzene (DNCB)
Uses :
Alopecia areata, Viral warts
MCQ’s
Q.1) Which is the measure for the quantity of drug to be applied
topically?
A. Finger Tip Unit
B. Hand Area Measurement
C. Both of these
D. None of the above
Q.2) Sunscreens provide protection against
A. UVA
B. UVB
C. UVC
D. UVA and UVB
MCQ’s
Q.3) All are indications of steroids except
A. Papulosquamous disorders
B. Pemphigus vulgaris
C. Telangiectsia
D. Polymorphous light eruptions
Q.4) All are keratolytic agents except
A. Glycolic acid
B. Lactic acid
C. Uric acid
D. Salicylic acid
MCQ’s
Q.5) Following factors affect the drug delivery except
A. Time of application
B. Site of application
C. Hydration
D. Massaging before application
Q.6) 28 year old female patient complains of multiple erythematous
papules and pustules in perioral region since last 20 days which is the
medication to be avoided in this patient?
A. Clindamycin
B. Framycetin
C. Mometasone furoate
D. Silver sulfadiazine
MCQ’s
Q.7) The following drug is commonly used as a first line therapy for
melasma.
A. Salicylic acid
B. Hydroquinone
C. Benzoyl peroxide
D. Urea
Q.8) A 4 year old child presented with pustular and crusted lesions on the
chin. MRSA was isolated on pus culture. Topical therapy of choice:A. Mupirocin
B. Povidone iodine
C. Silver sulfadiazine
D. Framycetin
Photo Quiz
Q. 7) Which topical agent can be used to
treat this condition?
Q. 8) Identify the topical preparation
and describe its indications?
Thank You!