ANTIINFLAMMATORY AGENTS are drugs that are used to reduce inflammatory responses in the body. Although inflammation is essentially a normal defensive mechanism (a reaction to tissue injury, infection, inhalation of foreign proteins), the manifestations may be so serious and inappropriate or involve such discomfort, that treatment with antiinflammatory agents is required. Inflammatory conditions can be acute (as in insect stings) or chronic (chronic asthma, dermatitis and other skin conditions, rheumatoid conditions). A wide range of drugs may be used to treat one or other inflammatory condition, and potential toxicity in relation to the medical condition is an important determinant of choice.

The NSAID ANALGESIC group has the widest antiinflammatory use, and their inhibitory antiinflammatory property is due to their cyclooxygenase activity (see CYCLOOXYGENASE INHIBITORS). Here the associated relief of pain is largely attributable to some degree of correction of the underlying inflammatory condition. Some of this group are relatively non-toxic and are available without prescription for use for relatively trivial complaints, e.g. aspirin and ibuprofen. (Paracetamol has insufficient antiinflammatory action to be useful here.) Others of this group are reserved for serious inflammatory conditions (notably in rheumatoid arthritis and osteoarthritis — often called antirheumatic or antiarthritic analgesics), e.g. diclofenac, fenoprofen. indomethacin, mefenamic acid, naproxen, phenylbutazone and piroxicam.

The CORTICOSTEROIDS are normally used for serious inflammatory conditions, though they are relatively safe when given by local application (skin creams or inhalation into the lungs in the prophylactic treatment of asthma). Local injection can be effective, e.g. into the affected region in tendinitis, or sometimes intrathecally. Systemic administration is normally reserved for short-term use or emergencies, such as anaphylactic shock. Examples of this type include betamethasone, clobetasoi, cortisone, hydrocortisone, prednisolone and triamcinolone.

The chromone group (e.g. sodium cromoglycate and nedocromil) are important ANTIALLERGIC and antiinflammatory drugs, as well as ANTIASTHMICS and other uses, though their mode of action is imperfectly understood.

A variety of antirheumatic drugs may be used, including gold-containing complexes (e.g. sodium aurothiomalate) and chelating agents (e.g. penicillamine).