Hii , Welcome To HCM & Thanks For Asking Your Query Here If your child vomits immediately after you give him an antibiotic you can see by looking at the vomit that he s thrown up the medicine, it s okay to give him another full dose. If she throws up again, contact her doctor. Re-dosing too frequently can cause diarrhea, especially with certain antibiotics. Most children will take and keep down an antibiotic, though, if it is given on a spoon like food or in an oral syringe down the inside of the cheek. Any substance that hits the middle of the tongue when a child isn t actively swallowing, on the other hand, may cause a gag reflex and vomiting. i would strongly suggest You to consult with your pediatrician to rule out the exact cause of the problem , he can decide whether medicines are right for your daughter or not , also he may opt for Parenteral administration (Through Injection ) if required i would strongly suggest you to see your pediatrician I hope it help Thanks & Get well Soon