Pharmacological properties : תכונות פרמקולוגיות

Pharmacodynamic Properties

5.1   Pharmacodynamic properties


ATC code:
Clotrimazole D01AC01
Dexamethasone D07AB19, D07CB04
Neomycin D06AX04
Mechanism of action

Clotrimazole
Clotrimazole acts against fungi by inhibiting ergosterol synthesis. Inhibition of ergosterol synthesis leads to structural and functional impairment of the fungal cytoplasmic membrane.
Clotrimazole has a broad antimycotic spectrum of action in vitro and in vivo, which includes dermatophytes, yeasts, moulds, etc.
Under appropriate test conditions, the MIC values for these types of fungi are in the region of less than 0.062-8.0 μg/ml substrate. The mode of action of clotrimazole is primarily fungistatic or fungicidal depending on the concentration of clotrimazole at the site of infection. In vitro activity is limited to proliferating fungal elements; fungal spores are only slightly sensitive.
In addition to its antimycotic action, clotrimazole also acts on gram-positive microorganisms (Streptococci / Staphylococci / Gardnerella vaginalis), and gram- negative microorganisms (Bacteroides).
In vitro clotrimazole inhibits the multiplication of Corynebacteria and gram-positive cocci - with the exception of Enterococci - in concentrations of 0.5-10 μg/ml substrate.
Primarily resistant variants of sensitive fungal species are very rare; the development of secondary resistance by sensitive fungi has so far only been observed in very isolated cases under therapeutic conditions.

Neomycin sulfate
Broad-spectrum bactericidal antibiotic effective against the majority of bacteria commonly associated with skin infections..

Dexamethasone acetate
Anti-inflammatory and anti-allergic glucocorticoid. It is used topically for its anti- inflammatory effects which suppress the clinical manifestations of the disease in a wide range of disorders where inflammation is a prominent feature.

Pharmacokinetic Properties

5.2   Pharmacokinetic properties
Clotrimazole
Pharmacokinetic investigations after dermal application have shown that clotrimazole is minimally absorbed from the intact or inflamed skin into the human blood circulation. The resulting peak serum concentrations of clotrimazole were below the detection limit of 0.001 mcg/ml, suggesting that clotrimazole applied topically is unlikely to lead to measurable systemic effects or side effects.

Dexamethasone
Distribution
Dexamethasone is about 77% bound to human plasma proteins in vitro.
Elimination
The mean plasma half-life of dexamethasone is about 4 hours
Metabolism
Dexamethasone is metabolized mainly in the liver but also in the kidney.
Excretion
Dexamethasone and its metabolites are excreted in the urine.