Week 4 - Therapeutics 2 Flashcards
Why Podiatrists use topical treatments
Applied directly to affected areas
lower doses required than systemically
reduces risk of interaction with other drugs
easily removed/stopped if reaction occurs
convenient for patients use
Topical treatment - DISADVANTAGES (2)
- Rely on patient to apply treatment
- patients wont use if they dont like the ‘feel’
Movement of topical medicaments through the skin (4)
- Absorption
- Penetration
- Permeation
- Reabsorption
ABSORPTION through the skin (2)
movement of topical medicament
- stratum corneaum = dead
- transport = diffusion
Factors affecting absorpton
- diffusion gradient
- no. of appendages
- level of skin hydration
- how often medicament is applied
- thickness of stratum corneum
Topical agents contain: (4)
- active ingredient (drug)
- vehicle or base (substance that helps carry it into skin)
- preservative (antibacterial/antimicrobial agent)
- stabiliser
What vehicles can be used to deliver drugs
- cream
- ointments
- lotions
- foams
- gels
- power
- sprays
- lacquer
Comparison of lotions, creams and oils
Lotions: less oil more water than cream
Creams - more runny less water
Ointments - more oil less water
Main groups of topical agents (7)
- Antiseptic
- Moisturisers
- Keratolytics
- Antifungals
- Vit D
- Corticosteroids
- Caustics
Antiseptics
chemical that stops or inhibits the growth of bacteria - kill bacteria or stop bacteria dividing
NMF
Natural moisturising factors
Function of NMFs in the skin
- Humectant - decreases transepidermal water loss
- lower skin pH - acts as a buffer against extreme pH changes
- Reduces bacterial load
Emollients vs moisturisers
Emollients - creates a seal
- lipids that occlude the skins surface
- prevent water loss
Moisturisers
- lipid emulsions that actively hydrate the skin
- humectant - draw in and hold water
Some products can have both properties
Types of emollients and moisturisers (3)
- regular skin application
- soap substitues
- bath additives
How to use emollients correctly (6)
- urea based prodcuts
- apply regularly
- avoid all soaps and use emoolient wash products
- best applied to warm, moist skin
- pumps = better then pots
- around 4-8g per day for feet
Moisturisers in practice (5)
- most dry skin conditions will benefit from a moisturiser
- best = greasiest one your patient will use
- avoid moisturisers with perfumes, colouring and sulphates (particularly for eczema)
- ointment based = more effective
- best way to relieve itch in dry skin conditions
Keratolytic agents (4)
- agents that soften, seperate and cause desquamation of the cornified epithelium or horny layer of skin - expose mycelia of infecting fungi or to treat corns, warts + other skin diseases
- Used to soften keratin
- improve the skins moisture binding capacity = beneficial in treatment of dry skin
- agents include alkali, salicylic acid, urea, lactic acid, allantoin, glycolic acid and trichloroacetic acid
Can Urea be used as a keratolytic
Yes
Caustics
strong inorganic acid or alkali or organic acid applied to soft tissue
- different caustics exert different actions on tissues
Imidazoles (Azoles)
- larger group of drugs based on their chemical structure
- work by inhibiting formation of cells walls
- primarily = fungistatic
- effective against dermatophytes, yeast and gram +vs bacteria
Allylamines
- Terbinafine
- broad spectrum antifungal agent
- fungicidal in action
Topical terbinafine
- most effective topical
- single daily application
- cure in around 1 wk
Use of topical antifungals
- used after washing skin first
- use for a min of 2 weeks after symptoms have clered due to liklihood of recurrance
- 1 finger tip unit per foot, per application
- low risk of local irritation
Corticosteriods
- Manufactured from cholesterol
- derived from 2 tissues in the human body
- modified by halogenation or esterification to enhance therapeutic uses
