Stability of acetylcysteine solution repackaged in oral syringes and associated cost savings

Extended Stability of Vasopressin Injection in Polyvinyl Chloride Bags and Polypropylene Syringes and Its Impact on Critically Ill Patient Care and Medication Waste

Background. Vasopressin is frequently utilized for a variety of shock states in critically ill patients. Short stability (≤24 hours) after intravenous admixture with current manufacturer labeling requires just in time preparation and may lead to delays in therapy and increased medication waste. We aimed to evaluate vasopressin stability in 0.9% sodium chloride stored in polyvinyl chloride bags and polypropylene syringes for up to 90 days. Additionally, we evaluated the impact of extended stability on the time to administration and cost savings from reduced medical waste at an academic medical center. Methods. Dilutions of vasopressin to concentrations of 0.4 and 1.0 unit/mL were performed under aseptic conditions. The bags and syringes were stored at room temperature (23°C-25°C) or under refrigeration (3°C-5°C). Three samples of each preparation and storage environment were analyzed on days 0, 2, 14, 30, 45, 60, and 90. Physical stability was performed by visual examination. The pH was assessed at each point and upon final degradation evaluation. Sterility of the samples was not assessed. Chemical stability of vasopressin was evaluated using liquid chromatography with tandem mass spectrometry. Samples were considered stable if there was <10% degradation of the initial concentration. Results. Vasopressin diluted to 0.4 and 1.0 unit/mL with 0.9% sodium chloride injection was physically stable throughout the study. No precipitation was observed. At days 2, 14, 30, 45, 60, and 90 all bags and syringes diluted to 0.4 units/mL had <10% degradation. Vasopressin diluted to 1 unit/mL and stored under refrigeration had <10% degradation at all measured days, but when stored under room temperature was found to have >10% degradation at day 30. Implementation of a batching process resulted in reduced waste ($185 300) and improved time to administration (26 vs 4 minutes). Conclusion. Vasopressin diluted to a concentration of 0.4 units/mL with 0.9% sodium chloride injection is stable for 90 days at room temperature and under refrigeration. When diluted to 1.0 unit/mL with 0.9% sodium chloride injection it is stable for 90 days under refrigeration. Use of extended stability and sterility testing to batch prepare infusions may lead to improved time to administration and cost savings from reduced medication waste.

Stability of N-Acetylcysteine 60 mg/mL in Extemporaneously Compounded Injectable Solutions

Background

N-Acetylcysteine (NAC) administered by the IV route is the current treatment of choice for acetaminophen overdose. However, the protocol approved by health authorities in most countries has a complex dosing regimen, which leads to dosage errors in one-third of cases. Therefore, the Canadian Antidote Guide in Acute Care Toxicology and individual poison centres have begun to recommend a simplified regimen using continuous IV infusion. Unfortunately, no study has demonstrated the stability of IV solutions of NAC at concentrations above 30 mg/mL or in solutions other than 5% dextrose.

Objective

To evaluate the stability of solutions of NAC 60 mg/mL in 0.9% sodium chloride, 0.45% sodium chloride, or 5% dextrose, stored for up to 72 hours in polyvinyl chloride (PVC) bags at 25°C.

Methods

Solutions of the desired concentration were prepared from a commercial solution of NAC 200 mg/mL, with dilution in 0.9% sodium chloride, 0.45% sodium chloride, or 5% dextrose, and were then stored at room temperature in PVC bags for up to 72 hours. At predetermined time points (0, 16, 24, 40, 48 and 72 h), samples were collected and analyzed using a stability-indicating high-performance liquid chromatography method. A solution was considered stable if it maintained at least 90.0% of its initial concentration. Particulate matter count was also evaluated to confirm chemical stability. Finally, organoleptic properties, such as odour and colour, were evaluated to assess the stability of the solutions.

Results

All solutions maintained at least 98.7% of their initial concentration. No obvious changes in odour or colour were observed. Moreover, particle counts remained acceptable throughout the study, according to the criteria specified in United States Pharmacopeia (USP) General Chapter <788>.

Conclusions

NAC 60 mg/mL, diluted in 0.9% sodium chloride, 0.45% sodium chloride, or 5% dextrose and stored in PVC bags at 25°C, was chemically and physically stable for a period of at least 72 hours.

Human Errors and Adverse Hemodynamic Events Related to "Push Dose Pressors" in the Emergency Department

BACKGROUND

Though the use of small bolus doses of vasopressors, termed "push dose pressors," has become common in emergency medicine, data examining this practice are scant. Push dose pressors frequently involve bedside dilution, which may result in errors and adverse events. The objective of this study was to assess for instances of human error and adverse hemodynamic events during push dose pressor use in the emergency department.

METHODS

This was a structured chart and video review of all patients age ≥ 16 years undergoing resuscitation and receiving push dose pressors from a single center from January 2010 to November 2017. Push dose pressors were defined as intended intravenous boluses of phenylephrine (any dose) or epinephrine (≤ 100 mcg).

RESULTS

A total of 249 patients were analyzed. Median age was 60 years (range, 16-97), 58% were male, 49% survived to discharge. Median initial epinephrine dose was 20 mcg (n = 139, IQR 10-100, range 1-100); median phenylephrine dose was 100 mcg (n = 110, IQR 100-100, range 25-10,000). Adverse hemodynamic events occurred in 98 patients (39%); 30 in the phenylephrine group (27%; 95% CI, 19-36%), and 68 in the epinephrine group (50%; 95% CI, 41-58%). Human errors were observed in 47 patients (19%), including 7 patients (3%) experiencing dosing errors (all overdoses; range, 2.5- to 100-fold) and 43 patients (17%) with a documentation error. Only one dosing error occurred when a pharmacist was present.

CONCLUSIONS

Human errors and adverse hemodynamic events were common with the use of push dose pressors in the emergency department. Adverse hemodynamic events were more common than in previous studies. Future research should determine if push dose pressors improve outcomes and if so, how to safely implement them into practice.

Guidelines for the Establishment of Appropriate beyond Use Dating of Sterile Compounded Admixtures

To support compounding of products that are sterile and chemically stable, beyond use dating of admixtures must include a thorough evaluation of appropriate resources. In most instances, resources provide documentation of a specific compounded admixture, at a specific concentration and storage parameters, that does not coincide with current operations or patient-specific requirements. To meet the operational demands of a pharmacy, institutions employ a referenced guideline approach to guide decision making for safe sterile admixing. Often these guidelines are established and maintained at individual practicing locations with varying levels of detail and accuracy. In an effort to improve sterile compounding across a multihospital system, we developed and implemented beyond use dating guidelines to improve consistency and patient safety while meeting regulatory concerns.