Clozapine-induced agranulocytosis: a situation report up to August 1976.

The frequency of agranulocytosis in association with clozapine therapy has been estimated and compared with data reported for phenothiazine-induced agranulocytosis. Apart from the "epidemic" in Finland, where the frequency was 21 times that in other countries, there is no evidence that clozapine-related agranulocytosis is more common than the phenothiazine-related disorder. Furthermore, results are given to show that strict adherence to precautionary measure (e.g. weekly blood counts) reduces the mortality-rate of this condition.