To record when a child has been issued medication you have two options - Medical notes and Medical events.
You could log a Medical note on the student profile.
If the medication is administered regularly, you can click into the Medical note on the student profile and update the summary box with the up to date information OR add to the summary box that this has been administered on another day.
This article explains how to add a medical note and how to pin this to a student profile so other staff members can see this.
Alternatively, you can log this as a medical event and put the category as 'Other'. You can see how to add a medical event here.
For this option, bear in mind that you would need to create a medical event for every day that medicine is administered. This would create a long list of medical events on the student profile and that will continue into the next academic year.