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 newer atypical agents have a lower risk of EPS , but are associated in varying degrees with sedation , cardiovascular effects , anticholinergic effects , weight gain , sexual dysfunction , hepatic effects , lowered seizure threshold ( primarily clozapine ) , and agranulocytosis ( clozapine only ) .
### Output Text:
The newer atypical agents have a lower risk of EPS , but are associated in varying degrees with sedation , cardiovascular effects , anticholinergic effects , weight gain , sexual dysfunction , hepatic effects , lowered seizure threshold ( primarily <span class="chemical">clozapine</span> ) , and agranulocytosis ( <span class="chemical">clozapine</span> only ) . 