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: The effectiveness of administration of glycopyrrolate 5 and 10 micrograms kg - 1 and atropine 10 and 20 micrograms kg - 1 i . v . immediately before the induction of anaesthesia , to prevent arrhythmia and bradycardia following repeated doses of suxamethonium in children , was studied .
### Output Text:
The effectiveness of administration of <span class="chemical">glycopyrrolate</span> 5 and 10 micrograms kg - 1 and <span class="chemical">atropine</span> 10 and 20 micrograms kg - 1 i . v . immediately before the induction of anaesthesia , to prevent arrhythmia and bradycardia following repeated doses of <span class="chemical">suxamethonium</span> in children , was studied . 