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: IMPLICATIONS : Administration of dexamethasone before succinylcholine was not effective in decreasing the incidence or the severity of succinylcholine - induced postoperative myalgia .
### Output Text:
IMPLICATIONS : Administration of <span class="chemical">dexamethasone</span> before <span class="chemical">succinylcholine</span> was not effective in decreasing the incidence or the severity of <span class="chemical">succinylcholine</span> - induced postoperative myalgia . 