Drug and non-drug factors influencing adverse reaction to pyrazoles.

Some of the factors influencing the likelihood of the appearance of adverse drug reactions in patients are identified and discussed. Ways of quantifying some of the risks of adverse reactions in different patients are demonstrated. It is pointed out that adverse reaction data can give valuable guidance for both day-to-day patient management and for the initiation or guidance of research projects. In this latter connection, this study highlights the difference in time of onset between aplastic anaemia and agranulocytosis, suggesting different mechanisms of reaction. The majority of adverse reactions occur during the first three weeks of treatment and it is during this time that patients must be most carefully supervised. The old patients should be watched with particular care. It is concluded that age, sex, disease being treated, length of treatment and even the geographical location where the patient lives, can affect the time, type, frequency and outcome of an adverse drug reaction.