It is usually best not to take metronidazole when children have a toothache. Metronidazole has no pain-relieving properties. Metronidazole is mainly used for the treatment of anaerobic bacterial infections, although the occurrence of toothache in children is likely to be related to anaerobic bacterial infections, but children’s spleen and stomach function is relatively weak, metronidazole on the gastrointestinal tract stimulation is relatively large, in the consumption of metronidazole after abdominal pain, loss of appetite, nausea, adverse reactions may occur. Therefore, it is recommended that children should not take metronidazole for toothache. It is best to go to the hospital’s stomatology department, can be under the guidance of a professional doctor to take pain medication or according to the specific type of infection germs use antibiotic drugs, such as roxithromycin, amoxicillin and so on, in order to help control the local inflammatory stimulus.