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: A patient with cholestatic hepatitis due to amiodarone treatment is presented below and a review of the hepatotoxicity of amiodarone is given .
### Output Text:
A patient with cholestatic hepatitis due to <span class="chemical">amiodarone</span> treatment is presented below and a review of the hepatotoxicity of <span class="chemical">amiodarone</span> is given . 