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: We present a case in which an 89 - year - old woman in a long - term care facility became confused after the initiation of misoprostol therapy .
### Output Text:
We present a case in which an 89 - year - old woman in a long - term care facility became confused after the initiation of <span class="chemical">misoprostol</span> therapy . 