In general, criteria for switch to PO therapy in RTI including stabilization of pulmonary function, normalization of temperature, ability to swallow and availability of a suitable agent can apply to a variety of syndromes. Levofloxacin has almost 100% bioavailability, appropriate pharmacodynamics and convenient dosage, and is therefore an important addition to IV-PO switch regimens. All the CAP trials previously quoted have used such regimens, with excellent results (14-16, 24).