Pharmacological Considerations of Current Methods of Therapy

Abstract

The two classes to true anti-inflammatory drugs are (1) glucocorticosteroids and (2) non-steroid (salicylate-like) anti-inflammatory agents. Other classes of drugs which are used as anti-allergics are the sympathomimetics or adrenaline-like compounds and the cromones.

Corticosteroids stabilise cellular and lysosomal membranes and thereby inhibit release of the chemical mediators of inflammation and proteolytic enzymes. Other glucocorticoid effects include inhibition of antibody synthesis; suppression of activity of fibroblasts; elevation of circulating neutrophil count and reduction in eosinophil count. Steroids also increase microvascular tone and decrease permeability thus reducing exudation and oedema formation.

Non-steroid anti-inflammatory drugs (NSAID) act principally to inhibit the biosynthesis of prostaglandine. The salicylate-like compounds also inhibit kallikrein activity and kinin formation and at the same time pharmacologically antagonise the tissue effects of kinins, prostaglandine and slow-reacting substance of anaphylaxis (SRS-A). NSAID are, with some exceptions, analgesic and antipyretic: effects not shown by corticosteroids.

The glucocorticoids have been utilised extensively in acute and chronic inflammation, particularly in afflictions of the skin, musculo-skeletal system and lung. These drugs are of no value in acute anaphylaxis or histamine stock. Salicylate-like drugs are used mainly for musculo-skeletal disorders. NSAID have been shown to be effective in controlling respiratory hypersensitivity in cattle and horses and are worthy of greater prominence in this respect. Adrenaline and related drugs are most often employed in situations involving allergic respiratory and cardiovascular impairment. Cromones, which prevent release of histamine, have not been employed in clinical veterinary medicine.