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 lower dose of 1 mg / kg i . v . of ( - ) - cibenzoline suppressed the digitalis - induced arrhythmia , whereas 5 mg / kg i . v . was needed to suppress adrenaline - induced arrhythmias .
### Output Text:
A lower dose of 1 mg / kg i . v . of ( - ) - <span class="chemical">cibenzoline</span> suppressed the <span class="chemical">digitalis</span> - induced arrhythmia , whereas 5 mg / kg i . v . was needed to suppress <span class="chemical">adrenaline</span> - induced arrhythmias . 