Is Focalin XR 5mg in mornings and Tenex 1mg twice a day for a 6 year old safe and any issues I?

Interactions between your drugs
Moderate
guanFACINE dexmethylphenidate
Applies to: Tenex (guanfacine), Focalin XR (dexmethylphenidate)

Before using guanFACINE, tell your doctor if you also use dexmethylphenidate. Taking these drugs together can affect the rhythm of your heart. Call your doctor if you have symptoms of irregular heartbeat, chest tightness, blurred vision or nausea. You may need a dose adjustment or need your blood pressure checked more often if you take both medications. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Source: https://www.drugs.com/interactions-check.php?drug_list=836-1783,1219-721

I suggest you discuss this potential interaction with your Dr.´s child.