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: Other possible adverse effects - - such as gastrointestinal disorders , orthostatic hypotension , levodopa - induced psychosis , sleep disturbances or parasomnias , or drug interactions - - also require carefully monitored individual treatment .
### Output Text:
Other possible adverse effects - - such as gastrointestinal disorders , orthostatic hypotension , <span class="chemical">levodopa</span> - induced psychosis , sleep disturbances or parasomnias , or drug interactions - - also require carefully monitored individual treatment . 