ATC Group: A07E Intestinal antiinflammatory agents

Balsalazide consists of mesalazine linked to a carrier molecule (4-aminobenzoyl-ß-alanine) via an azo bond. Bacterial azo-reduction releases mesalazine as an active metabolite in the colon. Mesalazine is an intestinal anti-inflammatory agent acting locally on the colonic mucosa. Its precise mechanism of action is unknown.

Beclometasone is a pro-drug with weak glucocorticoid receptor binding affinity. It is extensively hydrolysed via esterase enzymes to the active metabolite beclometasone-17-monopropionate (B-17-MP), which has potent topical anti-inflammatory activity.

Betamethasone is a glucocorticoid which is about eight to ten times as active as prednisolone on a weight-for-weight basis. Betamethasone has anti-inflammatory, antipruritic, and vasoconstrictive properties.

Budesonide is a glucocorticosteroid with a high local anti-inflammatory effect. At doses clinically equivalent to systemically acting glucocorticosteroids, budesonide gives significantly less HPA axis suppression and has a lower impact on inflammatory markers.

Sodium cromoglicate (Cromoglicic acid) inhibits the activation of many of the cell types involved in the development and progression of asthma. Thus, sodium cromoglicate inhibits the release of inflammatory mediators including cytokines from mast cells and reduces the chemotactic activity of eosinophils and neutrophils.

Hydrocortisone is the main glucocorticoid secreted by the adrenal cortex. Hydrocortisone is an anti-inflammatory steroid. Its anti-inflammatory action is due to reduction in the vascular component of the inflammatory response and reduction in the formation of inflammatory fluid and cellular exudates.

Mesalazine is an aminosalicylate. The mechanism of action of mesalazine is not fully understood, but appears to have a topical anti-inflammatory effect on the colonic epithelial cells. Mucosal production of arachidonic acid metabolites, both through the cyclooxygenase and lipoxygenase pathways, is increased in patients with chronic inflammatory bowel disease, and it is possible that mesalazine diminishes inflammation by blocking cyclooxygenase and inhibiting prostaglandin production in the colon.

Olsalazine is bioconverted to 5-aminosalicylic acid (5-ASA), which has anti-inflammatory activity in ulcerative colitis. The conversion of olsalazine to mesalamine (5-ASA) in the colon is similar to that of sulfasalazine, which is converted into sulfapyridine and mesalamine. The mechanism of action of mesalamine (and sulfasalazine) is unknown, but appears to be topical rather than systemic.

Prednisolone is a glucocorticoid which has anti-inflammatory activity. Naturally occurring glucocorticoids (hydrocortisone and cortisone), which also have salt-retaining properties, are used as replacement therapy in adrenocortical deficiency states. Their synthetic analogs are primarily used for their potent anti-inflammatory effects in disorders of many organ systems.

Prednisone is a synthetic glucocorticoid with anti-inflammatory and immunomodulating properties. After cell surface receptor attachment and cell entry, prednisone enters the nucleus where it binds to and activates specific nuclear receptors, resulting in an altered gene expression and inhibition of proinflammatory cytokine production. This agent also decreases the number of circulating lymphocytes, induces cell differentiation, and stimulates apoptosis in sensitive tumor cell populations.

Therapeutic benefit of sulfasalazine appears to be due to a local action of the sulfasalazine and its split product 5-aminosalicylic acid on the mucous membrane and deeper colonic structures.

Tixocortol is a 21-thiol derivative of hydrocortisone classified as a class A corticosteroid. It is a synthetic steroid with topical anti-inflammatory properties without the systemic glucocorticoid and mineralocorticoid activities and toxicity.