Hi I Was Administering 10 Ml Doses Of Amoxicillin To

Hi I was administering 10 ml doses of amoxicillin to my 19 lb 10 month old child ,5ml every 12 hours at 11 o'clock. I missed last night and gave it to him as soon as I could which was 4 AM. Am I supposed to make the next one back at 11 o'clock or maintain the 12 hour intervals and wait until 4 PM?