In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: BACKGROUND AND PURPOSE : The Intravenous Nimodipine West European Stroke Trial ( INWEST ) found a correlation between nimodipine - induced reduction in blood pressure ( BP ) and an unfavorable outcome in acute stroke .
### Output Text:
BACKGROUND AND PURPOSE : The Intravenous <span class="chemical">Nimodipine</span> West European Stroke Trial ( INWEST ) found a correlation between <span class="chemical">nimodipine</span> - induced reduction in blood pressure ( BP ) and an unfavorable outcome in acute stroke . 