Antipyretic analgesics and the allergic patient.

Recent studies of idiosyncratic reactions to analgesics have revealed several clinical patterns with different pathogeneses. In the common type of asthma precipitated by aspirin, inhibition of cyclooxygenase leads to disturbances in the metabolism of arachidonic acid. Drugs that precipitate possibly life-threatening bronchoconstriction and are absolutely contraindicated in patients with aspirin-induced asthma include indomethacin, mefenamic acid, flufenamic and meclofenamic acids, ibuprofen, fenoprofen, ketoprofen, naproxen, diclofenac, amidopyrine, noramidopyrine, phenylbutazone, flumizole, and ditazol. If necessary, patients with aspirin-induced asthma can safely take, even on a long-term basis, salicylamide, dextropropoxyphene, benzydamine, guaiacolic ester of salicylic acid, and chloroquine. In some patients with urticaria/angioedema, symptoms are due to inhibition of cyclooxygenase by analgesics; in others, the cause may be impurities in commercial preparations of aspirin; and in still others, the mechanisms remain unknown.