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: In our case , use of the Naranjo probability scale indicated a possible relationship between the hypertensive crisis and amisulpride and tiapride therapy .
### Output Text:
In our case , use of the Naranjo probability scale indicated a possible relationship between the hypertensive crisis and <span class="chemical">amisulpride</span> and <span class="chemical">tiapride</span> therapy . 