Sentence: Pretreatment of the rats with methamphetamine ( MAP ) for 8 days prior to chronic haloperidol significantly enhanced the DOPAC and HVA increase produced by the challenge with haloperidol in both brain areas .
Drug combination annotation:
[{'class': 'POS', 'spans': ['methamphetamine', 'haloperidol'], 'is_context_needed': False}]