It is not recommended to combine Tylenol and Advil for a baby. One of the medications should be enough to control the fever unless advised by a medical professional. The recommended dose of Advil for a baby weighing 33 lbs is 150mg every 6 to 8 hours, up to 4 times in a 24-hour period. If you have Advil concentrated at 100mg/5ml, this would be equivalent to giving 7.5ml every 6-8 hours. Make sure to consult with a healthcare provider before administering any medications to your child.