Can The Bro-Zedex Expectorant Be Given To A Toddler?

My 2.8 yrs old kid was coughing badly, like I used to do few days back, so I gave him my medicine Bro-Zedex Expectorant 2ml. Only after I checked the dosage and saw its only for adults. I am really worried now if it s going to cause serious health issues. Please help me what should I do now? I am really scared now.