Aminopyrine-induced blood dyscrasias--still a problem in many parts of the world.

The aminopyrines were introduced about a century ago as analgesics and antipyretics, but it was not until the 1930s that agranulocytosis, their major adverse reaction, was recognized. In patients receiving aminopyrines, although agranulocytosis is the most frequent blood dyscrasia, aplastic anaemia has also been reported. For these reasons, these drugs have been banned or withdrawn from the market in most industrialized countries. However, aminopyrines are still available in many parts of the world, including the Far East, Africa and Latin and South America and can be found as adulterants in some 'herbal' patent preparations. Their continuing availability in the Far East may have contributed in part to the higher incidence of aplastic anaemia, compared with the West.