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: We have reported a case of acute oliguric renal failure with hyperkalemia in a patient with cirrhosis , ascites , and cor pulmonale after indomethacin therapy .
### Output Text:
We have reported a case of acute oliguric renal failure with hyperkalemia in a patient with cirrhosis , ascites , and cor pulmonale after <span class="chemical">indomethacin</span> therapy . 