wk 8- inflammatory Flashcards
anti histamines
reduces the effects mediated by the chemical histamine as it competes with histamine for binding sites at the H1 receptor
histamine is released during allergic responses
antihistamines are competitive h1 receptor antagonists
what does histamine do
histamin can bind to H1, H2 H3, h4
h1- stimulates smooth muscle contraction in lungs/gastro tract, stimulates sensory nerve (pruritus and sneezing), increase vascular permeability (swelling)
all reactions of an allergy
what is urticaria
redness and swelling of the dermis causing it to to alway be itchy
caused by histamine causing small blood vessels to leak
when are anti histamines useful
acute situations
allergic skin reactions (tape, dressings)
pruritic conditions (itchiness)
for sedation before procedures
classification of anti histamines
first generation
-sedating
second generation
-less sedating
sedating anti histamines can help what
anti pruritic
anti nausea
motion sickness
sedation
adverse effects of sedating anti histamines
- dry mouth
- blurred vision
- constipation
- urinary retention
- bronchial mucous thickening
- drowsiness
sedating anti histamines are contraindicated in
glaucoma
prostatic hypertrophy
phernogen also called
promethazine
less sedating anti histamines are what
h1 antagonists that do not cross the blood brain barrier
less lipophilic and lesser anticholinergic side effects
types of 2nd gen anti histamines
desloratadine
fexofenadine
loratadine
adverse effects of less sedating anti histamines
droswiness
fatigue
headache
nausea
dry mouth
desloratadine
indicated in
allergic rhinitis
chronic urticaria
loratadine
lower potency anti histamines
indicated in
sesaonal rhinitis
urticaria
precautions in populations for anti histamines
breast feeding
pregnancy
elderly
hepatic/renal impairment (depends on drug)
fexofenadine
indicated in
allergic rhinitis
chronic urticaria
when giving an antihistamine to a child what age should they be over
2 years
topical corticosteroids effects
anti inflammatory
immunisuppressant
anti proliferative
vasoconstrictive
when to use a topical corticosteroid for inflammatory skin conditions (indications)
contact dermatitis
atopic dermatitis/ eczema
venous stasis dermatitis
psoriasis
hypergranulated ulcer
how can topical ingredients pass through the skin
- trans epidermal
- trans appendageal - through sweat glands and follicules)
factors affecting absorption of topicals
diffusion gradient
number of appendages
level of skin hydration
how often medicament applied
thickness of stratum corneum
how long and what strength of corticosteroids can podiatrists prescribe
10 day course
up to 1% potency
what conditions of the skin increases absorption
inflammed
diseased
hydrated
temperature
how do topical corticosteroids work
bind to and activate glucocorticoid receptor
what are the anti proliferative effects of corticosteorids
thinning of stratum corneum
long term use collagen and elastic fibres diminished
when to use ointment
if dry, lichenified skin- better penetration and less of an irritant
when to use cream
weepy skin- less of an irritant and less occulsive
when to use lotion
hairy areas- more appendengeals and lotions can absorb rapidly through these
how much topical corticosteroids should you apply
fingertip unit (0.5g)
when do you see the most adverse effects with corticosteroids
with long term use
ADRs of corticosteroids
-adrenal suppression
-infection (immunosuppressant)
-sodium/water retention
-swelling
-hypertension
-hyperkalemia
-delayed healing
-skin atrophy
-allergic dermatitis
-vehicle related AEs (itching, burning, irritation)
-bruising
-muscle wasting
-psychiatric effects (euphoria, depression, mood swings)
what to consider with corticosteroids
age- child or infant
potency
use of occlusion
duration- prolonged increases risk
location- thick/thin skin, appendages which all affect penetration
what is tachyplylaxis
tolerance to the action of a drug after repeated doses
reduce risk by 2 weeks on, 1 week off
what is usually the reason for drugs not workin
non compliance
misusing
what is steroid rebound phenomenon
sudden, dramatic rebound of the disease is observed after stopping therapy often more severe than previously
what potency to use
mod, potent and very potent, no need to use mild
where to use topical corticosteroids
thick lesions/plantar surface (thick skin)
how long can you use topical corticosteroids
2-3 weeks only (10 days for pods, need to involve GP if longer required)
how many times do you apply corticosteroids
once daily
when to use cortico
early evening
once in maintenance what to do?
step down to weaker steroid
what can you use corticosteroids with?
emollient
how could a first generation antihistamine interact with respiratory disorders, cardiovascular disease or concurrent CNS depressant
CVD- tachycardia as a side effect
talking about this being in exams
study
what do corticosteroids do to diabetics/ blood glucose control?
causes hyperglycameia by blocking the action of insulin
