Correct cough medication for a five year old

Patient: Can a five year old have a nebulizer treatment of levalbuterol hci ( 0.63 mg/3ml) after taking 5ml of cough syrup (dextromethorphan 5mg/guaifenesin 100mg)?

Symptoms: Runny nose, heavy cough

Doctor: Thank you for your question. Although there are no adverse interactions between these medications we recommend waiting a t least 2-4 hours before administering each dosage of medication. Please be guided accordingly.Thank you for consulting