Endogenous androgens are responsible for normal growth and development of the male sex organs and for maintenance of secondary sex characteristics. These effects include growth and maturation of the prostate , seminal vesicles , penis , and scrotum ; development of male hair distribution, such as beard , pubic, chest, and axillary hair; laryngeal enlargement, vocal cord thickening, and alterations in body musculature and fat distribution. Drugs in this class also cause retention of nitrogen , sodium, potassium , and phosphorous, and decreased urinary excretion of calcium. Androgens have been reported to increase protein anabolism and decrease protein catabolism . Nitrogen balance is improved only when there is sufficient intake of calories and protein.
Dosage requirements of corticosteroids vary among individuals and the diseases being treated. In general, the lowest effective dose is used. The oral dose range is 2-60 mg daily depending on the disease. Depo-medrol doses are 10-80 mg injected into muscle every 1-2 weeks, and Solu-medrol doses are 10-250 mg intravenous or intramuscular injections up to 6 times daily. The initial dose should be adjusted based on response. Corticosteroids given in multiple doses throughout the day are more effective but also more toxic than the same total daily dose given once daily, or every other day.
Activated charcoal can act as an adsorbent (kind of a "chemical sponge") to bind toxins in the gut. If you use a preparation that is safe for people and use a smaller dose, it should be harmless.
If the problem was an insect sting, I doubt that there are any toxins in the gut that the charcoal would help with.
So many times we are unable to determine the source of the allergen.
Kenalog is a long-acting corticosteroid (cortisone) injection that stays in the body for weeks, where the dexamethasone lasts only a couple of days.
Antihistamines like benadryl are often helpful for something like an insect sting, even though most dogs don't get much relief from them in regard to allergic itching.