Injectable Meds: Beyond Sterile Prep
News stories about sterile preparation of injectable medications have been making headlines for what seems like years. This makes sense, because breaches of proper procedures can and have led to serious patient harm, including deaths. However, there are a number of other considerations that pharmacy technicians should be aware of concerning the preparation and dispensing of injectable medications. These can include creation and maintenance of documents that help standardize preparation of injectable medications to fielding phone calls from nurses who have questions about administering injectable medications. This Technician Tutorial will cover this type of practical information for pharmacy technicians.
You are delivering meds for patients on the medicine floor at your hospital. You have a dose of vancomycin 1 g to be given every 12 hours to a female patient, Bonnie Bratton. It is to infuse over two hours, which you recognize as the usual infusion time for this dose of vancomycin. You place the dose in the refrigerator, in the bin designated for doses for Ms. Bratton. The dose is due at 9:00 a.m., and you are delivering this first dose at 8:15 a.m. There is plenty of time for the nurse to access it and hang it by 9:00 a.m.
What does USP Chapter <797> cover?
USP Chapter <797> deals with the sterile preparation of medications, such as those meant for intravenous, intramuscular, ophthalmic, spinal, or subcutaneous injection. This involves everything from proper garbing prior to entering the clean room to what can be stored in the clean room to actual technique and equipment requirements for cleanrooms. There is also guidance on beyond-use dating of parenteral preparations, as well as for single- and multidose vials.
What other information do I need to consider with regard to prepping injectable medications?
Most pharmacies have documents and procedures in place to standardize preparation of injectable medications. For example, a standard diluent, either 5% dextrose (D5W) or normal saline (NS), may be preferred for piggybacks and infusions, unless the medication is incompatible with that diluent (e.g., phenytoin, which can precipitate in D5W), or unless the stability of a prep will be significantly shortened when the preferred diluent is used (e.g., TMP-SMX, where stability is much shorter in NS than in D5W, or ampicillin-sulbactam, where stability is much shorter in D5W than in NS).
This type of standardization can serve a number of purposes, such as simplifying prep, preventing confusion and mix-ups in the pharmacy, and helping simplify the ordering process for prescribers.
In addition, a chart that includes beyond-use dates and proper storage (e.g., refrigeration, room temperature) to be used for injectable medications that are commonly prepared can save time and also prevent any mistakes when pharmacists or technicians are assigning beyond-use dates to prepared doses for batches, or as they are ordered.
Other information that can be added to these types of documents, and even to patient-specific labels generated by the pharmacy’s or hospital’s computer system, can include special considerations such as when a filter must be used for the administration of a medication or if a drug should be prepared in a particular type of container. For example, phenytoin piggybacks should be administered through a 0.22 or 0.5 micron filter due to the risk of precipitation. Intravenous amiodarone is a drug that should be prepared in either a glass bottle or PVC-free bag of D5W to avoid reactions with PVC. And doses of “vinca alkaloids” such as vincristine or vinblastine should be prepped in IV piggybacks, not in syringes, to prevent fatal wrong-route errors (i.e., inadvertent intrathecal administration). These types of special considerations are typically exceptions to the rule, and can be easy to forget if a person doesn’t commonly prepare or dispense these meds. Another example is the requirement for light protective coverings, such as opaque bags or foil wraps, that must be used for some meds, such as nitroprusside infusions, to prevent degradation of the drug.
Another aspect of injectable med prep that should be standardized is how “overfill,” or extra solution in an IV bag, syringe, vial, or ampule should be handled. IV bags of diluents typically have a few mL of overfill, and vials and ampules may also have some extra solution. This leads to the need to consider how overfill affects prep of meds. Some meds may need to be added to exact amounts of diluents (e.g., chemo, pediatric dilutions), while the small amount of extra diluent may not matter for other types of meds (e.g., antibiotics, IV fluids). Extra solution in an amp or vial may need to be accounted for in some cases, or disposed of in a specific manner, such as for controlled substances. You may actually need to overfill some preps, such as doses that require small volumes of meds in syringes. This can help make up for lost volume, such as when a nurse places a needle on a syringe for intramuscular or subcutaneous injection, and a small amount of med stays in the “dead space” of the needle hub. Another type of med that’s commonly overfilled is eye injections. Keep in mind, however, that most meds in syringes are administered with needle-less systems, so you won’t often need to consider overfill in syringes for this reason. Handling overfill consistently is the key, so it’s important to be aware of and follow your pharmacy’s policies.
Medications that are added to your hospital’s formulary and possibly non-formulary meds that are used periodically should be added to these standardized procedures documents. Meetings are typically held monthly that look at adding new drugs to formulary. Work with your pharmacist to see how you can help keep these documents up-to-date. This might involve actually collecting information, such as from the drug’s package insert or a drug compatibility reference, submitting change requests for computer updates, or making sure any hard copies of such documents located throughout the hospital are switched out when there are updates.
What other information do I need to consider with regard to dispensing injectable medications?
Of course you will want to make sure that injectable meds are delivered to the proper place on a patient care unit. If a medication needs to be refrigerated, such as most IV piggybacks, it will need to be placed in a refrigerator on the unit in order to maintain its stability through the assigned beyond-use date. This is often a point of confusion for nurses, especially for meds that come in vials, such as erythropoietin (Epogen, etc). If you receive reorders for these types of meds, make sure that the nurse is checking the refrigerator for the dose prior to redispensing it.
Likewise, a few IV piggybacks must be stored at room temp, such as linezolid (Zyvox) or metronidazole (Flagyl). Because nurses most often expect IV piggybacks to be stored in the fridge, there may be confusion when they’re looking for these meds. Follow the same advice as above when you see reorders for these meds. Nurses may be looking in the wrong place for them and think that the dose has not been delivered. Help them out by letting them know that these particular meds are always stored at room temp because when refrigerated there can be problems such as precipitation of the drug. Once they know, they won’t be likely to forget!
Also, with regard to special types of devices that must be used with meds, be mindful of what comes from the pharmacy and what is stocked on patient care units such as from central supply. A good example is the 0.22 micron filter used for phenytoin IV piggybacks, as mentioned in the last section. If these are stocked on the unit as opposed to being sent by pharmacy, you may still get calls from nurses looking for the filters. If you already know the answer, you can save time by letting them know where they can access the filters.
The next day you are working the same shift and covering the same patient care unit. You see a dose of Ms. Bratton’s vancomycin in the refrigerator return bin on the patient care unit. This med must have been discontinued. You notice that you have a dose of linezolid (Zyvox) 600 mg IV to deliver for her as well. This med will be infused over one hour, and it is administered every 12 hours. Linezolid IV doses are to be kept at room temperature, so you do not place this dose in the refrigerator. Fortunately, there is an auxiliary label on the bag to remind you not to place it in the refrigerator. In addition, doses of linezolid must be kept in their foil overwraps until they are used. So unlike most doses of IV meds, this one is still in its packaging.
What do IV drug compatibilities involve?
It’s hard to imagine that any pharmacy technician who works in a hospital has not received a phone call from a nurse asking if two or more IV drugs can be administered through the same IV line, at the same time. The situation is somewhat self-explanatory, but here are a few more details to give you a more accurate picture.
If a patient has a peripheral IV line, which means the IV goes into a peripheral vein such as in the arm, the line will have ports, or openings, where IV medications and fluids can be attached to run into the line. These are called “y-sites.” If two IV medications, let’s say the antibiotic cefazolin as an IV piggyback which will be infused over 15 minutes, and the pain medication morphine which is ordered as a continuous infusion, need to be infused together, it is important to know if they are “compatible.” Drugs are considered INcompatible if they chemically deactivate one another, or if they are physically unstable and precipitate into chunks or crystals when they are mixed. There are experts who perform studies to see whether either of these things happen when certain drugs are mixed. Extensive information on drug compatibilities can be found in most drug information references. Some hospitals might even create their own charts that include commonly used IV drugs. In our example, a nurse could administer these two meds, cefazolin and morphine, through the same IV line, because they are compatible. (Double check in a drug info reference to verify this if you have one available.)
If a patient has a central line (an IV line that’s inserted into a large vein) or a peripherally-inserted central catheter (PICC), things can get a bit more complicated. These IV lines have multiple lines, or lumens, attached together, and the solutions that are administered through them will not mix until they reach the patient’s bloodstream. So you can see that the drugs may not mix directly, as they would through a peripheral IV line.
Now that you have more details about IV compatibilities, it’s easy to understand the information a pharmacist will need in order to answer IV compatibility questions from nurses. When you get one of these calls, ask for the names of the drugs, their scheduled times, and the type of IV line or number of lines the patient has in order to improve efficiency. If you are comfortable with the pharmacist’s preference for which drug information reference to access, you may want to go ahead and get that information ready as well. Ultimately, pharmacists will typically want to speak with nurses themselves to share the information, in addition to any strategies that may be needed due to drug incompatibilities, since an incorrect answer or any kind of mix-up could potentially lead to patient harm.
If drugs are incompatible, the pharmacist may recommend rescheduling one of them so they can be infused at separate times. Or, an IV drug may be switched to an oral formulation if appropriate. Sometimes administration of a dose might need to be delayed if IV access that requires placement by a physician or specially-trained nurse is necessary.
When you return to the pharmacy, you answer a number of phone calls. One of them is from Ms. Bratton’s nurse. Ms. Bratton is receiving other IV medications and the nurse wants to know if he can infuse them together with linezolid. You ask the nurse the names of the meds, and he tells you that one is ½ normal saline with potassium chloride 20 mEq, which is infusing at 80 mL/h continuously. The other med is a dose of phenytoin. You ask the time that the phenytoin is due and he tells you it is a one-time dose of 1 g to be infused over one hour at 11:00 a.m. The dose of linezolid is due at the same time. You ask the nurse how many IV lines he has available, and he says he has one peripheral line.
You ask the nurse if he minds to hold for a minute or two and pass this information on to the pharmacist. The pharmacist accesses a reference to find out about drug compatibilities. After a couple of minutes, she picks up the phone. The pharmacist asks the nurse a number of additional questions, and then decides to recommend switching the phenytoin to an oral formulation. The pharmacist had determined that these two drugs could not be infused at the same time, because they are not compatible.
How should doses of injectable meds that are returned to the pharmacy be handled?
This can be much trickier than simply returning doses to the pharmacy shelves, as is often done for unit dose capsules and tablets. Typically, any partially-used injectable meds will be disposed of by the nurse on the patient care unit, according to hospital policies and procedures. So pharmacy technicians will be mostly concerned with unused doses of injectable medications that are returned.
You’ll want to follow your pharmacy’s policies and procedures for returning unused doses of injectable meds to the pharmacy. For example, some pharmacies may dispose of any dose of an injectable med that was dispensed in a syringe (e.g., patient-specific insulin doses, pediatric doses) regardless of whether or not they are expired and stored properly on the patient care unit. For IV piggybacks such as antibiotics and infusions such as insulin or heparin, these will most often be able to be returned to pharmacy stock if they are still in date and if they were stored properly after dispensing. If they are returned to stock, they will be able to be reissued to another patient. Again, become familiar with policies and procedures about what is allowed at your hospital.
Later in the day, you return to the patient care unit where Ms. Bratton is staying. You find the discontinued dose of IV phenytoin in the return bin. You bring the dose back with you to the pharmacy and ask the pharmacist how to handle it. Should the dose be discarded, or can it be kept for reissue to another patient? The pharmacist does some quick checking and tells you that the dose can be reused as long as the beyond-use date has not passed. However, when you check, the beyond-use date has actually passed. The prep is only good for four hours after it is mixed. Since this is the case, the dose will need to be wasted. However, you do remove the unused 0.22 micron filter that was dispensed with the dose, and place it back in the proper bin so it can be dispensed with another med that requires the use of a filter.
Project Leader in preparation of this PL Technician Tutorial (310881): Stacy A. Hester, R.Ph., BCPS, Associate Editor
Cite this document as follows: PL Technician Tutorial, IV Meds: Beyond Sterile Prep. Pharmacist’s Letter/Pharmacy Technician’s Letter. August 2015 (Last modified August 2017).