Switch over from intravenous to oral therapy: A concise overview

Majority of the patients admitted to a hospital with severe infections are initially started with intravenous medications. Short intravenous course of therapy for 2-3 days followed by oral medications for the remainder of the course is found to be beneficial to many patients. This switch over from intravenous to oral therapy is widely practiced in the case of antibiotics in many developed countries. Even though intravenous to oral therapy conversion is inappropriate for a patient who is critically ill or who has inability to absorb oral medications, every hospital will have a certain number of patients who are eligible for switch over from intravenous to oral therapy. Among the various routes of administration of medications, oral administration is considered to be the most acceptable and economical method of administration. The main obstacle limiting intravenous to oral conversion is the belief that oral medications do not achieve the same bioavailability as that of intravenous medications and that the same agent must be used both intravenously and orally. The advent of newer, more potent or broad spectrum oral agents that achieve higher and more consistent serum and tissue concentration has paved the way for the popularity of intravenous to oral medication conversion. In this review, the advantages of intravenous to oral switch over therapy, the various methods of intravenous to oral conversion, bioavailability of various oral medications for the switch over program, the patient selection criteria for conversion from parenteral to oral route and application of intravenous to oral switch over through case studies are exemplified.