<p>Fusidic acid is only effective against gram-positive bacteria such as Streptococcus, Staphylococcus aureus and Corynebacterium minutissimum. The antibacterial action of fusidic acid results from inhibition of bacterial protein synthesis. The drug interferes with amino acid transfer from aminoacyl-tRNA to protein on the ribosomes. Betamethasone induces lipocortin which inhibits phospholipase A-2 enzyme which results in the inhibition of different inflammartory mediators synthesis like prostaglandins, cinins, histamines.<br />
<br />
Pharmacokinetics: Fusidic acid can penetrate intact human skin. As much as 2% of the amount of topically applied fusidic acid penetrates intact skin. The degree of penetration depends on factors such as the duration of exposure to fusidic acid and the condition of the skin. Fusidic acid is excreted mainly in the bile with little excreted in the urine. Dermal absorption and potency of any topical corticosteroid including betamethasone depends on the vehicle in which the steroid is delivered. Absorption of betamethasone may be higher in certain body areas such as the face, groin, axilla, or on injured or inflamed skin such as the lesions of atopic dermatitis.</p>