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: One week later , by mistake , losartan was prescribed again and after the second dose of 50 mg , the patient developed a second episode of transient anuria lasting 10 hours .
### Output Text:
One week later , by mistake , <span class="chemical">losartan</span> was prescribed again and after the second dose of 50 mg , the patient developed a second episode of transient anuria lasting 10 hours . 