Phenacetin and aminopyrine were used previously as pain killers but were banned in hong kong in 1983 and 1984 respectively due to their severe side effects . phenacetin may cause haemolytic anaemia , methaemoglobinaemia and sulfhaemoglobinaemia while aminopyrine may lead to agranulocytosis 非那西丁和氨基比林曾用来作止痛之用，但因其可引致严重副作用，已分别于1983及1984年在香港禁售。
