###Human: The tooth has become a bit yellow in a child after taking antibiotic. What is the reason? ###Assistant: Hello. I have been through your query and I can understand your concern. You do not need to panic. Generally, the discoloration of the teeth is a reversible process and when the medication is stopped, the discoloration also gets corrected. The tooth discoloration has many reasons and yes one of them is medicine. There are several medications that may cause discoloration of the teeth like Tetracycline antibiotics cause blackish to brownish discoloration. However, sometimes it is not the medication as such that causes the discoloration. The medicines of babies usually contain some sweetening agent in order to make the drug sweet to taste. On regular consumption of the drug, the teeth might show decay or yellow discoloration. I would suggest you visit the same doctor who prescribed the medication for your baby and ask him if the medicine might have any side effects of causing discoloration. You can also send me the name of the antibiotics that the baby is on, so I can see if those drugs could cause any kind of discoloration. Meanwhile, maintain good oral health of your baby. Rinse his or her mouth with water after taking medication and foods (breastfed milk included). Clean his teeth with cotton ball gently and massage his gums gently. This will ensure safety from further damage to the teeth. I would suggest you to keep on continuing these cleaning tips till the baby is 2 years old. After 2 years, the toothbrush can be used to clean the teeth. If you are able to maintain the oral hygiene of your baby till 3 years, the overall oral health of the baby for the coming future will be good and there will be a decrease in the incidence of the dental related problems.