&NA;ZD 9379 is an orally active glycine antagonist that is entering phase II clinical investigation with Zeneca in the UK for the treatment of acute stroke and pain.ZD 9379 is a potent full antagonist at the glycine site of the NMDA receptor. It resulted in a substantial decrease in infarct size and in the number of spreading cortical depressions in a rat model of permanent cerebral ischaemia, without causing any observable adverse effects. This drug is the first glycine site antagonist to exhibit simultaneous inhibition of spreading depressions and infarct volume. It remains to be determined whether the correlation between the number of spreading depressions and infarct volume may reflect a causal relationship.