wk 8- antifungals Flashcards
types of antimycotics
topical
1. azoles
2. allylamines
3. mopholines
4. polyene
oral
1. allylamines
2.mitosis inhibitors
3. azoles
azole antifungals
topical:
bifonazole
ketoconazole
fluconazole (oral only)
clotrimazole
oral:
itraconazole
fluconazole
allylamine antifungals
terbinafine
MOA azole
fungistatic
can be fungicidal at larger doses
interrupt the synthesis from lanosterol to ergosterol
MOA allylamines
fungicidal
interrupts the synthesis with an increase in squalene within the cell membrane and deficiency of ergosterol
nystatin MOA
fungicidal
bind to ergosterol in fungal cell membrane and causes depolarization
griseofulvin MOA
fungistatic
disrupts spindle formation during mitosis and arrests metaphase
fungal species
- trichophyton rubrum (76%)
- trichophyton interdigitale
- epidermophyton floccosum
types of tinea pedia
- interdigital
- hyperkeratotic/moccasin
- inflammatory / vesticular
- ulcerative
types of onychomycosis
tinea unguium
diagnosising tinea pedis
microscopy and culture not generally needed when starting topical therapy
culture may take up to 6 weeks
topical corticosteroid and fungal infections
used in conjunction initially if itching is severe- typically for inflammatory/vesticular tinea
removes redness but it allows the infection to spread as it decreases the immune response and therefore should not be used alone
signs of infection will return and be worse than before on withdrawal of corticosteroid - tinea incognito
treatment for plantar/hyperkeratotic/moccasin tinea
oral- ETG
treatment for inflammatory/vesicular tinea
oral
oral therapy when
- widespread
- topical hasnt worked
- topical corticosteroid used inappropriately
- on scalp, palms or soles
- inflammatory, hyperkeratotic, vesicular in nature
types of oral therapy
- azole
fluconazole
itraconazole
2.allymadine
terbinafine
griseofulvin is effective and cheaper but a longer treatment course
length of oral therapy
terbinafine/fluconazole :usually 4 week course
itraconazole: one week course but need to review 3-4 weeks after and repeat if cultures are positive
types of onychomycoiss
- white superficial onychomycosis
- distal subungal onychomycosis
- candida onychomycosis
- proximal subungual onychomycosis
diagnosis onychomyosis
microscopy and culture before treatment
positive in approx 80% of cases of OM
what species causes white superficial onychomyococisis
usually trichophyton interdigitale
treatment for white superficial
- topical miconazole tincture
- topical amorolfine
when would u not use topical therapy on onychomyosis
distal subungal onychomyocosis or
proximal subungal onychomyosis
doesnt penetrate the nail to reach the source
oral therapy for onychomycosis and success rate and length of treamtent for nails
- terbinafine (70-80%)- 12 weeks or longer
- azole (60-70%)
itraconazole 3-4months
fluconazole: 6-12 months - griseofulvin (30%) after 12 months and relapse common
why would u use oral therapy for onychomyociss
-widespread
-topical not working
-the type, DSO, PSO unable to penetrate
-risk of infection, neuropathy, PAD, ulceration, complications (diabetic, immune suppressent, delayed healing)
poor prognosis for onychomyocosis when
- area of infection more than half the nail
- significant lateral infection
- subungal hyperkeratosis >2mm
- white/yellow streaks
- total dystrophic
- non responsive organism
- immunosuppressive patients
- diminished peripheral circulation
terbinafine contraindications- oral
- hepatic
-liver disease - psoriasis
-need to diagnose infection first - children
-rare to occur in children, tablet not recommended and cream not for children <12 - antidepressents
-TCA (increases side effects)
-venlafaxine and paroxetine
what can you use lamisil once for
interdigital tinea pedis only
leave to dry to a film and dont wash area for 24 hours
what can you use cream, gel or spray lamisil for
tinea corporis
tinea cruris
interdigital tinea pedis
renal impairment and oral therapy
half dose
terbinafine and monitoring liver function
liver function test at baseline, monitor if treating longer than 6 weeks
it can cause elevated LFT and liver toxicity and blood dyscrasias
symptoms of dark urine, tired, nauesous, etc
formulations of topicals and what they suit
cream- dry scaling tinea
tincture- nails
spray- cant reach, hairy or painful on touch areas
lotion- between toes for drying
mixonazole has what for azoles
the most fromulation options
cream
lotion
powder
spray
tincture
solution
bifonazole is
used once daily and has the shortest duration fo treatment 2-3weeks compared to other azoles
hydrocortisone and antifungals
only used until inflammation subsides (max 7 days) and must be used with antifungal at least 2 times a day
topical treatments for onychomycosis
- amorolfine -nail licquer solution. once/twice weekly
- miconazole - tincture
- urea (2-3weeks) and bifonazole cream (4weeks)
- ciclopirox -lacquer
how long does it take for a nail to grow out
12 months or more
what is not effective if nail matrix is infected
topical
griseofulvin- oral tablet length of treatment and contraindications
12 months for nails
4-6 weeks for skin
- pregnancy/lactation
- heaptic dysfunction
- lupus erythemateosus (burning with sun exposure side effect)
- combined oral contraceptive
- warfarin
side effects of griseofulvin
- skinburn
- headache
- dizziness
