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: Lidocaine , given in a 300 mg dose intramuscularly followed by 100 mg intravenously , did not prevent sustained ventricular tachycardia , although there was a significant reduction in the number of patients with warning arrhythmias between 15 and 45 minutes after the administration of lidocaine ( p less than 0 . 05 ) .
### Output Text:
<span class="chemical">Lidocaine</span> , given in a 300 mg dose intramuscularly followed by 100 mg intravenously , did not prevent sustained ventricular tachycardia , although there was a significant reduction in the number of patients with warning arrhythmias between 15 and 45 minutes after the administration of <span class="chemical">lidocaine</span> ( p less than 0 . 05 ) . 