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 incidence of drug - related dependent edema was somewhat higher in the amlodipine group , particularly at a dose of 10 mg per day ( 2 . 4 % for 80 mg valsartan ; 3 . 6 % for 5 mg amlodipine ; 0 % for valsartan plus 5 mg amlodipine ; 14 . 3 % for 10 mg amlodipine ) .
### Output Text:
The incidence of drug - related dependent edema was somewhat higher in the <span class="chemical">amlodipine</span> group , particularly at a dose of 10 mg per day ( 2 . 4 % for 80 mg <span class="chemical">valsartan</span> ; 3 . 6 % for 5 mg <span class="chemical">amlodipine</span> ; 0 % for <span class="chemical">valsartan</span> plus 5 mg <span class="chemical">amlodipine</span> ; 14 . 3 % for 10 mg <span class="chemical">amlodipine</span> ) . 