Initiating IV to PO Switches

June 2011 - Vol.8 No. 6 - Page #2
Categories: Ready-to-use IV Products, Unit Dose Pharmaceuticals

While most institutional physicians and pharmacists are aware of the cost and clinical benefits of intravenous to oral (IV to PO) medication switches, many health systems continue to struggle with implementing a successful IV to PO program. Clearly communicating the benefits of appropriate IV to PO switches to staff and instituting precise policies and procedures for these switches will ensure patients’ medication needs are met while affording the facility significant cost savings. A proactive stance when deciding which drugs can be switched and at what point in treatment it is safe to do so will improve patient safety and help mitigate costs to the facility.

Exploring the Benefits of IV to PO Switches 
Perhaps the most obvious positive of converting from IV to PO is that drug costs are decreased, as most PO medications are less expensive than their IV counterparts. Beyond saving on the actual cost of the medication, additional savings are realized by eliminating IV sets and pumps and reducing nursing and pharmacy personnel time spent on IV-related activities. Several studies published in the last decade document the cost savings associated with successful IV to PO conversion programs.

From a clinical perspective, patients who are converted to PO earlier in treatment and recovery may have an easier time ambulating, as they are not connected to IV poles, and switching to PO lessens the risk for infusion-related adverse events that are associated with their IV equivalents. Expeditious removal of IV catheter lines during a patient’s hospital stay reduces the risk of developing secondary infections associated with IV lines. Furthermore, as IV to PO switches decrease the average patient’s length of stay in a hospital, the overall risk of developing hospital-acquired infections is reduced. In many cases, PO drugs are more easily acquired and handled, and are more convenient for the pharmacy because they take up less space and are easier to store in larger quantities than IV medications. 

Admittedly, in today’s health care setting, some of the financial benefits are not as pronounced as in the past because lengths of stay are decreasing overall. Nonetheless, the savings associated with these programs, in conjunction with the patient care benefit, make them well worth the effort invested.

Who Should Be Switched from IV to PO?
Automated mechanisms are very useful in determining which patients are the best candidates for IV to PO therapy changes. Performing a search of the pharmacy information system for all patients taking a specific medication helps identify patients eligible for conversion. In addition, there are several electronic antibiotic surveillance systems that have rules written into their programming to identify which patients are candidates based on pre-established criteria. 

Initiating an IV to PO Protocol
The drugs that are initially targeted when beginning an IV to PO conversion program should be those that have the best bioavailability, including antibiotics, such as azithromycin, ciprofloxacin, levofloxacin, linezolid, metronidazole, and moxifloxacin; antifungals, such as fluconazole; and gastrointestinal drugs, such as famotidine, ranitidine, and proton pump inhibitors. The exception to this list is azithromycin, which has only 40% bioavailability orally but is able to achieve high tissue penetration, even in its PO form. 

A manageable first step is to start with a targeted list of five or six drugs that have been approved by the P&T committee for switching and that are used in the hospital extensively (see Figure 1 for a sample IV to PO conversion order form). After this list has been determined, all pharmacists should be trained on the types of patients most eligible for conversion. Pharmacy can then take a leadership role in IV to PO implementation by clearly advertising the benefits to the medical and nursing staff. When doing this, be sure to clarify current policies with case management to ensure that reimbursement is not put at risk, and include that information in your communications. Automating the switch based on a policy and procedure previously approved by the medical staff is the ideal approach. 

Many hospitals will expand their initial list of drugs amenable to conversion to include other highly bioavailable medications that may not be used as frequently. They also may target IV medications that have no exact oral equivalent, but for which a pharmacologically similar one is available. For example, converting from IV ceftriaxone to oral cefpodoxime (step-down therapy) may be an option in some cases. 

When to Prohibit Switches or Practice Caution 
Certain drugs should never be switched from IV to PO. For example, vancomycin in oral form is poorly absorbed in the GI tract and does not achieve high enough concentrations to appropriately treat systemic infections. The only niche for this form of the drug is in the treatment of Clostridium difficile. Because of the poor absorption of oral vancomycin, a large concentration of the drug is able to remain in the GI tract, and tests have revealed very high concentrations in some patients. This is an important characteristic for a drug used to treat an infection of the GI tract. 

Do not switch drugs being used for difficult-to-treat or severe infections, such as sepsis, osteomyelitis, endocarditis, or where titration to a therapeutic level is actively ongoing (eg, antiarrhythmics). Other IV drugs require additional oversight when converting to PO, examples of which include certain cardiac medications, antiseizure medications, and antifungals. Blood concentrations need to be monitored carefully during a switch, as they can be associated with clinical changes and toxicity. 

Caution needs to be exercised to avoid converting to PO therapy in situations where the patient has a physiological issue that might preclude them from absorbing the full dose of the medication. For example, a patient who is vomiting or has an issue with malabsorption in the GI tract may not absorb enough of the drug to produce the intended clinical effect. Patients who are receiving enteral feedings and are switched to PO medications also may exhibit a subtherapeutic response. For these patients, PO antibiotics can bind to the tube feeding, thus leading to lower concentrations in the blood, which may cause poor therapeutic response and antimicrobial resistance. Similarly, the use of PO antiepileptics may result in lower drug levels in the blood, which can increase the incidence of seizure.

IV to PO Switches in Bariatric Surgery Patients
Specific care also should be exercised during IV to PO switches for patients who have undergone certain types of bariatric surgery, as these patients are likely to have issues with malabsorption. Changes in the stomach volume after surgery causes a decrease in gastric acid production and a higher pH compared with preoperative stomach function. This change in pH can reduce the efficacy of drugs that rely on an acidic pH for absorption. Bariatric procedures that decrease the size of the stomach could further decrease drug bioavailability.1

There have been many anecdotal reports of bariatric surgery patients exhibiting problems with drug absorption, including one in which a patient became anemic and had to receive IV iron because he was not able to absorb enough iron orally. Of course, anecdotal reports are not proof of malabsorption issues in these patients, but nevertheless it is prudent to be vigilant when considering switching these patients to PO medications. As hospitals are now seeing more and more morbidly obese patient admissions, making complex IV to PO conversion decisions for this patient population will become increasingly common.

Click here to view a larger version of this Table

Changing Prescribers’ Frame of Reference 
A prescriber’s hesitancy to institute IV to PO switches sometimes can be the result of patient discharge or reimbursement issues rather than strict clinical concerns, and most hospitals have a standard protocol to minimize switches lacking an explicit indication to do so. With this in mind, the theory still exists in health care that maintaining a patient on IV medications will allow the hospital to justify an extended stay in the facility when clinicians suspect an additional disease state may exist or when a longer supervised recovery time is preferred. Clinicians may be working with case management to find placement for a patient with social limitations that could hinder his or her ability to maintain medication therapy or self care after discharge, and the thought is that maintaining the patient on IV therapy will provide the justification to keep the patient in the hospital until those issues are resolved.

This mindset can backfire, however, as for many insurers, simply maintaining IV status alone does not meet the necessary criteria for reimbursement of extended services. This does vary from carrier to carrier, though. 

Reporting Success to Administration
Being able to measure the success of an IV to PO conversion program to hospital decision makers—both financially and from a patient safety perspective—is certainly expected. To enable a positive outcome, create a comparison of purchase costs for both IV and PO medication therapies, making sure to factor in the equipment costs for IV setups and tubing. Determine what percentage of purchased medications are in IV form and what percentage are in oral form. In most hospitals, these numbers are around 60% IV and 40% oral when, in fact, clinically and financially the inverse of those numbers would be more beneficial. There is no hard and fast rule, but setting a target of 60% oral therapies and 40% IV would be an ambitious goal. Finally, calculate the savings gained based on the reduction in the number of IV units as a result of the IV to PO processes, and present these numbers to administration. 

The 60/40 IV/PO split has traditionally been the case in many facilities, perhaps because the average inpatient stay is five days, and so for the first three days patients are treated intravenously, while after three days, physicians are more comfortable switching to oral medications. Making a commitment to institute earlier switches for patients who fit the necessary criteria could save an entire day of IV costs per patient, per stay.

Conclusion
While practically all facilities are aware of the substantial cost savings of early switching of patients from IV to PO medications, putting a successful process in place and ensuring that all health care providers are adhering to the policy remains challenging. Instituting a successful IV to PO program for those drugs that are comparatively easy to switch will set the stage for more challenging medications. Educating decision makers and physicians and taking a leadership role in this long-term process allows pharmacy to provide financial savings for the facility while still maintaining patient medication safety. 

Reference

  1. University of Illinois at Chicago College of Pharmacy Drug Information Group Web site. FAQs. http://dig.pharm.uic.edu/faq/2011/Mar/faq3.aspx Accessed May 4, 2011.

 


Kristi Kuper, PharmD, BCPS, is the clinical director of infectious diseases for Cardinal Health and is based in Houston, Texas. She received her doctor of pharmacy from the University of Nebraska Medical Center and completed a postgraduate pharmacy practice residency at the James A Haley Veterans Hospital in Tampa, Florida. Kristi developed an antimicrobial stewardship training program that has been completed by almost 1000 pharmacists in the US and Puerto Rico. In addition, she is a site coordinator for the University of Houston/Cardinal Health infectious diseases specialty pharmacy residency. 

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