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: Taken together , our results confirm the good tolerability of nimesulide and paracetamol in patients who experienced urticaria / angioedema caused by NSAIDs .
### Output Text:
Taken together , our results confirm the good tolerability of <span class="chemical">nimesulide</span> and <span class="chemical">paracetamol</span> in patients who experienced urticaria / angioedema caused by <span class="chemical">NSAIDs</span> . 