Final answer:
The best course of action for the PT would be to administer dexamethasone for inflammation.
Step-by-step explanation:
Iontophoresis is a therapeutic technique that uses electric current to deliver medication through the skin. In the case of lateral epicondylitis, or tennis elbow, iontophoresis can be used to deliver anti-inflammatory medication to the affected area. Considering that the medication is for inflammation, the best course of action for the PT would be to administer dexamethasone, which is a corticosteroid that has anti-inflammatory properties.