Brand Name: Betatrex
Generic Name: Betamethasone Dipropionate
Topical corticosteroids are synthetic derivatives of cortisone which are effective when applied locally to control many types of inflammatory, allergic and pruritic dermatoses. Certain modifications to the chemical structure of hydrocortisone increase the anti-inflammatory potency of the molecule. For example, introduction of fluorine atoms into the molecule enhances anti-inflammatory activity. The more potent topical corticosteroids are generally more effective and more likely to cause adverse effects than less potent preparations.
Topically applied corticosteroids are thought to act by controlling the rate of synthesis of proteins. The overall effect of corticosteroids is a catabolic one. Topical corticosteroids inhibit the migration of macrophages and leukocytes into treated areas by reversing vascular dilation and permeability. With repeated administration to the same site, 3 times daily for 4 to 5 days, tolerance to the anti-inflammatory effects of the drug may occur. Withdrawal of the drug for 2 to 4 days should restore the response; however, tolerance will recur once application is restarted. Many dermatological disorders respond equally well to low-potency corticosteroids such as hydrocortisone, although for severe acute dermatoses a more potent preparation may be preferred initially. Some dermatoses may require occlusion of the drug under a plastic film or intralesional administration.
Pharmacokinetics
Following topical application to normal skin, corticosteroids are minimally absorbed. Only small amounts of drug reach the dermis and are then absorbed into the systemic circulation. Absorption is greater when corticosteroids are applied to certain areas of the body, including the scalp, face, eyelid, axilla and scrotum. Absorption will also be increased if the epidermis is damaged by disease or inflammation or by the use of different vehicles or occlusive dressings. Continued absorption of corticosteroids may occur, even after washing, due to retention of the drug in the stratum corneum.
Following rectal administration or application of corticosteroids to the mucosa of the genitourinary tract, significant systemic absorption may occur. As much as 30 to 90% of hydrocortisone when administered as a retention enema may be absorbed. Absorption will be further increased if the mucosa is inflamed. Hypothalamic pituitary adrenal (HPA) axis suppression may occur.
Corticosteroids: Topical
Comparative Potencies
| Weak
Hydrocortisone
Hydrocortisone acetate
Methylprednisolone
Methylprednisolone acetate
|
| Moderately Potent
Clobetasone 17-butyrate
Desonide
Flumethasone pivalate
Fluticasone propionate
Hydrocortisone valerate
Prednicarbate
Triamcinolone acetonide
|
| Potent
Amcinonide
Betamethasone valerate
Desoximetasone
Diflucortolone diacetate
Fluocinolone acetonide
Fluocinonide
Halcinonide
Mometasone furoate
|
| Very Potent
Betamethasone dipropionate
Clobetasol 17-propionate
Halobetasol propionate
|
|
