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 main side effects of subcutaneous apomorphine treatment are related to cutaneous tolerability problems , whereas sedation and psychiatric complications play a lesser role .
### Output Text:
The main side effects of subcutaneous <span class="chemical">apomorphine</span> treatment are related to cutaneous tolerability problems , whereas sedation and psychiatric complications play a lesser role . 