No history of anaphylactic/anaphylactoid-type event manifested by disseminated urticaria, laryngeal edema, and/or bronchospasm (or for example: food, insect bites, etc). Patients with drug allergies, manifested solely by rash and/or urticaria, are not excluded. An isolated episode of urticaria occuring more than 3 years earlier is not a contraindication.