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: CONCLUSIONS : Clinicians should be aware of the possibility of acute liver insult induced by bupropion given concurrently with other hepatotoxic drugs .
### Output Text:
CONCLUSIONS : Clinicians should be aware of the possibility of acute liver insult induced by <span class="chemical">bupropion</span> given concurrently with other hepatotoxic drugs . 