Final answer:
Methylphenidate, a commonly used medication to treat ADHD, can cause abnormal liver function tests (LFTs) as a side effect. Regular monitoring of liver function is important during treatment.
Step-by-step explanation:
One medication commonly used to treat ADHD in children/adolescents is methylphenidate, which is a stimulant drug. Although it is generally safe and effective for most individuals, there is a possibility of abnormal liver function tests (LFTs) as a side effect. Abnormal LFTs can indicate liver damage or inflammation, and it is important to monitor liver function regularly during treatment with methylphenidate.