A method of delivering a drug in a vessel includes positioning an inflatable balloon that is located at a distal end of an ultrasonic device within a lumen of the vessel, the inflatable balloon being deflated and coated with at least one drug; inflating the inflatable balloon; and transmitting a vibration to the distal end of the ultrasonic device to dislodge the drug from the inflated inflatable balloon and deliver the drug to an interior portion of the vessel.