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 patient with chronic renal failure ( CRF ) developed neuroleptic malignant syndrome ( NMS ) after administration of risperidone and levomepromazine .
### Output Text:
A patient with chronic renal failure ( CRF ) developed neuroleptic malignant syndrome ( NMS ) after administration of <span class="chemical">risperidone</span> and <span class="chemical">levomepromazine</span> . 