Final answer:
Methylphenidate should be monitored when combined with TCAs or citalopram due to potential interactions.
Step-by-step explanation:
Methylphenidate, also known as Ritalin, is a stimulant drug commonly used to treat ADHD and narcolepsy. When combined with tricyclic antidepressants (TCAs) or citalopram, caution is advised due to the potential for interactions between these medications. Monitoring is recommended to assess for any adverse effects or drug interactions.