Final answer:
The first drug you should administer is epinephrine.
Step-by-step explanation:
In this case, the first drug you should administer to the infant with severe symptomatic bradycardia associated with respiratory distress would be epinephrine. Epinephrine is a medication that stimulates the beta-1 receptors in the heart, which increases the heart rate. It also causes vasoconstriction, which helps improve blood pressure and blood flow. Administering epinephrine can help reverse the bradycardia and improve the infant's heart rate and respiratory distress.