Parents and students at Glenda Dawson High School, where the incident took place, reacted to the news Tuesday.
"I wonder, what's the rationale behind that? I guess maybe they wanted to go home or something and kids do things that I don't understand," said Edward Jasmine.
Police said the boys -- two 14-year-olds and two 15-year-olds -- ingested the medicine in one of the school's restrooms.
One of the boys had brought four bottles of Delsym cough syrup.
Each teenager drank a full bottle.
After they returned to class, a teacher noticed one of the students were behaving differently and appeared to be in distress.
The teacher sent him to the nurse, who discovered that he had an elevated heart rate and blood pressure.
That's when the teenager admitted that he had consumed the cough syrup with the other boys.
"In the end, all four were transported to Memorial Hermann Southeast Hospital for evaluation," said Onesimo Lopez with the Pearland Police Department
Delsym is a strong medicine with a 12 hour time release, which is meant to be taken in teaspoonfuls.
It's so strong that it is often placed behind the counter.
"If they take too much of it trying to keep chasing that high, they could end up overdosing and may actually even die from it," said Lopez.
The students may face public intoxication charges.