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: Adverse effects forced a reduction in the dose of amiodarone in 41 % and discontinuation of amiodarone in 10 % of patients .
### Output Text:
Adverse effects forced a reduction in the dose of <span class="chemical">amiodarone</span> in 41 % and discontinuation of <span class="chemical">amiodarone</span> in 10 % of patients . 