3375
Ammonia ( NH3 ) was higher in patients who , during continuous therapy , complained of drowsiness ( 7 patients ) than in those who were symptom - free ( 17 patients ) , although VPA plasma levels were similar in both groups .
 Chemical: Ammonia; Chemical: NH3; Disease: drowsiness; Chemical: VPA
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: Ammonia; Chemical: NH3; Disease: drowsiness; Chemical: VPA