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: This is inconsistent with the well - established finding that nifedipine induces tachycardia in normally innervated hearts .
### Output Text:
This is inconsistent with the well - established finding that <span class="chemical">nifedipine</span> induces tachycardia in normally innervated hearts . 