Purpose: To evaluate the risk of anaphylaxis following exposure to medications given during hospitalization.
Methods: Cases with anaphylaxis and controls, matched according to length of hospital stay, were enrolled from hospitals in Hungary, Spain, India and Sweden. Exposures were recorded from the hospital record. The incidence of anaphylaxis was calculated among those exposed to various drugs, with denominators estimated from exposure rates in the controls and number of hospitalizations.
Results: Among 184 cases and 1003 controls, the incidence of anaphylaxis was in the range of 5-15 cases per 100,000 exposed patients for most analgesics and antibiotics administered orally or parenterally; for parenteral penicillin, it was 32. Incidence estimates were somewhat higher for blood, dextran, pentoxifylline and both ionic and nonionic contrast media, ranging from 35 to 95 cases. The highest estimates were for streptokinase and plasma, at 378 and 284. With no exposed controls, the incidence could not be calculated for anti-snake venom, but it was clearly higher than for other exposures.
Conclusions: Although anaphylaxis is known to occur following exposure to a large number of drugs, the incidence is not well documented. We have demonstrated a relatively low risk for dipyrone, diclofenac, paracetamol, ampicillin, cloxacillin and cephalosporins. An intermediate risk was shown for parenteral penicillin, dextran, contrast media, blood and pentoxifylline. The highest incidence was observed for plasma, streptokinase and anti-snake venom (the latter used only in India).