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: The syndrome reversed after discontinuing risperidone and starting treatment with dantrolene and bromocriptine .
### Output Text:
The syndrome reversed after discontinuing <span class="chemical">risperidone</span> and starting treatment with <span class="chemical">dantrolene</span> and <span class="chemical">bromocriptine</span> . 