Is it safe to give a 14 month old benadryl (diphenhydramine) when she is already taking 5ml of zyrtec?

Benadryl (diphenhydramine): This can be risky. Both have anti-histamine effects. I advise not to stack them. If you wish to separate the administrations by 5-6 hours, then it would be safer.

Ok: Zyrtec is not approved for use in such a young child. Benadryl (diphenhydramine) can cause sedation. Best would be evaluation by her doctor

Yes, but reduce dose: Both are antihistamines and work slightly differently in the body so one may be more effective than the other, but when used together have an added effect as far as sedation and dry secretions, etc. I prefer using one or the other, but it would be safe to overlap the two medications for a few doses but recommend decreasing the dose or frequency. Call doctor if breathing is labored.

Not recommended: Strictly speaking neither Zyrec or Benadryl (diphenhydramine) are currently recommended for children under 2 y/o. However, every child is different. One child that age may have no trouble with this combo. while another may get significant side effects. Ask your child's pediatrician. He or she can help you decide if the benefit is worth the risk.

NO: Benadryl (diphenhydramine) and Zyrtec should not be given together.