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: Three patients who had experienced neuroleptic - induced akathisia in the past reported that the symptoms of fluoxetine - induced akathisia were identical , although somewhat milder .
### Output Text:
Three patients who had experienced neuroleptic - induced akathisia in the past reported that the symptoms of <span class="chemical">fluoxetine</span> - induced akathisia were identical , although somewhat milder . 