A method for providing a therapeutic effect to a treatment site within a patient's vasculature comprises positioning a catheter at the treatment site. The catheter includes a heating element and a fluid delivery lumen that is coupled to an exit port within a distal region of the catheter. The method further comprises passing the therapeutic compound through the delivery lumen and the exit port at a flow rate. The heated therapeutic compound is provided to the treatment site. The method further comprises exposing at least a portion of the treatment site and at least a portion of the delivered heated therapeutic compound to ultrasonic energy generated by the ultrasound radiating member.