ORAL PROVOCATION OF INTOLERANCE TO NONASP IRIN ANALGESICS

Although intolerance reactions to analgesics are not uncommon, there i s still a lack of standardized procedures to diagnose the problem. We retrospectively analyzed results of scratch tests as well as oral chal lenges with analgesics in order to evaluate risk and diagnostic releva nce of these procedures. In 1987-1992 a total of 650 patients with sup posed intolerance to drugs were tested by oral challenge. Among them w ere 98 patients with a positive history of intolerance to non-aspirin analgesics. In 56 patients the intolerance could be verfied by oral ch allenge. In order of decreasing frequency, the most likely agents were propyphenazone, diclofenac, metamizole, ibuprofen, carbamazepine, ind omethacin, phenazone (antipyrine), and paracetamol (acetaminophen). Or al provocation showed clear dose-response relationships. For propyphen azone, the half-effective provocation dose was the same for all sympto ms (cutaneous, nasal, bronchial, anaphylactoid), Scratch testing was n ot of diagnostic significance, Standardized test protocols starting wi th low dose oral challenges are suitable and helpful in minimizing the risk of severe side effects.