4304
For sumatriptan , tightness in the chest caused by an unknown mechanism has been reported in 3 - 5 % of users .
 Chemical: sumatriptan
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 Chemical: sumatriptan