indication

For the maintenance treatment of asthma as prophylactic therapy in patients 5 years of age and older. Also being investigated for oral treatment in mild-to-moderate Crohn's disease of ileal or ileal-right colonic localisation and for "topical" use mild-to-moderate graft versus host disease.

pharmacology

Beclometasone, a synthetic halogenated glucocorticoid with antiinflammatory and vasoconstrictive effects, is used for treating steroid-dependent asthma, allergic or nonallergic rhinitis, or recurrent nasal polyps.

mechanism of action

Unbound corticosteroids cross cell membranes and bind with high affinity to specific cytoplasmic receptors. The result includes inhibition of leukocyte infiltration at the site of inflammation, interference in the function of mediators of inflammatory response, suppression of humoral immune responses, and reduction in edema or scar tissue. The antiinflammatory actions of corticosteroids are thought to involve phospholipase A2 inhibitory proteins, lipocortins, which control the biosynthesis of potent mediators of inflammation such as prostaglandins and leukotrienes. For the investigated use in the treatment of GvHD or Crohn's, beclometasone acts by binding to interleukin-13 to inhibit cytokines, which in turn inhibits inflammatory chemicals downstream.

toxicity

The acute toxicity of beclometasone dipropionate is low. The only harmful effect that follows inhalation of large amounts of the drug over a short period of time is suppression of hypothalamic-pituitary-adrenal (HPA) function. Chronic: The excessive use of beclometasone dipropionate over a long period could lead to adrenal suppression.

biotransformation

Metabolism mediated via esterase enzymes that are found in most tissues. Undergoes rapid and extensive conversion to beclomenthasone-17-monopropionate (17-BMP) during absorption

absorption

Mean peak plasma concentration was 88pg/ml at 0.5 hour

half life

2.8 hours

route of elimination

Irrespective of the route of administration (injection, oral or inhalation), BDP and its metabolites are mainly excreted in the feces. Less than 10% of the drug and its metabolites are excreted in the urine.