ANTIFUNGAL, CS Flashcards
Terbinafine
• Allylamine
Fungicidal
Terbinafine Blocks the biosynthesis of
inhibits
ergosterol, a sterol essential to the integrity
of the fungal cell membrane;
squalene epoxidase (fungal inhibited 4X more than mammalian)
Terbinafin AND synthesis of steroid hormones, prostaglandins, and drug metabolism
Does not interfere with
Terbinafine with liver dysfunction
slow elimination by 30%
Terbinafine lesser degree efficacy
cutaneous candidiasis
Terbinafine and ?cytochrome p450 superfamily
does not inhibit
Itraconazole, Fluconazole, keto Triazole
• Inhibits
14-α-demethylase, blocking lanosterol conversion to ergosterol
Itraconazole is Highly lipophilic
• Bioavailability increased
• Needs environment for absorption
postprandially
acid
Itraconazole Adr
hypertriglyceridemia, edema, hypertension, leukopenia, elevated LFTs, nephrotic syndrome
Itraconazole , Keto, FLUCO
Inhibits cytochrome P450
→ elevates
inhibits, Small affinity for incr digoxin, cyclosporine, triazolam, fluco Elevates phenytoin, warfarin, nortriptyline, midazolam, triazolam, and tacrolimus
Ketoconazole by interfering with androgen
and glucocorticoid synthesis
gynecomastia and
impotence,
acid environment for absorption
enhanced by food intake
lipophilic
Ketoconazole itraconazole
Ketoconazole common effects on liver (fulminant hepatitis and transient increases in LFTs)
•
FALSE
Fluconazole Rarely elevated LFTs
T
Fluconazole for prolonged use at 400 mg
Alopecia
Griseofulvin
• Disrupts microtubule mitotic spindle formation
•
causing metaphase arrest
Griseofulvin Absorption enhanced
fatty meal
Griseofulvin• Indicated for onychomycosis, but
cure rate is low and relapse rate is high
Griseofulvin 20-50% experience
severe headaches
Griseofulvin
• exacerbator of
contraindicated in
• Photoallergy precipitate LE severe skin reactions
patients with a history of porphyria
acute intermittent porphryia
Griseofulvin diff fr azoles in metab
• Induces cytochrome P450
Griseofulvin
Ineffective against candidiasis, systemic mycoses, and Pityrosporum species
• Has been reported as a potential
atrophy and striae formation,
through suppression of
collagen cross-linking during synthesis
Systemic Corticosteroids ? circulating lymphocytes T-cell responsiveness to antigens release of lysosomal enzymes response of macrophages to lymphokines antibody production lymphocytes, eosinophils, and monocytes
number of polymorphonuclear leukocytes
- Decrease
* Increase
Short-acting steroids, cortisone and hydrocortisone, mineralcorticoid activity,
cortisone has the____ glucocorticoid activity
greatest
lowest
Intermediate and long-acting steroids, methylprednisolone, triamcinalone, dexamethasone, betamethasone
no mineralcorticoid activity,
shorter acting CS have higher
but lower
Why we prefer shorter acting CS in treatment? Has lower GC activity, but higher MC activity, less adrenal suppressaion,
MC
GC
dexamethasone and
betamethasone have the highest
glucocorticoid activity
mimic normal circadian cortisol production
•
single morning dosing,
Risk of HPA axis suppression is minimized in acute disease
All complications are believed to be reduced by alternate-day dosing except
the risk of
posterior subcapsular cataracts, osteoporosis, and osteonecrosis
sodium retention, potassium
wasting, open-angle glaucoma, myopathy
steroid adr
