Medication Safety in Intravenous Therapy: A Compatibility Study of Clonidine with Drugs Frequently Used in Intensive Care

Physicochemical compatibility of caffeine citrate and caffeine base injections with parenteral medications used in neonatal intensive care settings

PURPOSE

To investigate the physicochemical compatibility of caffeine citrate and caffeine base injections with 43 secondary intravenous (IV) drugs used in Neonatal Intensive Care Unit (NICU) settings.

METHODS

Caffeine citrate (20 mg/mL or 10 mg/mL) or caffeine base injection (10 mg/mL) were mixed in a volume ratio of 1:1 with the secondary drug solution to simulate Y-site co-administration procedures in NICUs. Physical compatibility was evaluated based on visual observation for 2 h, against a black and white background and under polarised light, for changes in colour, precipitation, haze and evolution of gas. Chemical compatibility was determined from caffeine concentration measurements, using a validated high-performance liquid chromatography assay.

RESULTS

Six of the 43 secondary drugs tested (aciclovir, amphotericin (liposomal), furosemide, hydrocortisone, ibuprofen and ibuprofen lysine) were physically incompatible with caffeine citrate undiluted injection (20 mg/mL), at their high-end, clinically relevant concentrations for NICU settings. However, when tested at lower concentrations, hydrocortisone (1 mg/mL) was physicochemically compatible, whereas furosemide (0.2 mg/mL) was physically incompatible with caffeine citrate. The six drugs which showed physical incompatibility with caffeine citrate 20 mg/mL injection were also physically incompatible with caffeine citrate 10 mg/mL solution. All 43 secondary drugs tested were physicochemically compatible with caffeine base injection.

CONCLUSIONS

Most secondary test drugs, except aciclovir, amphotericin (liposomal), furosemide, hydrocortisone, ibuprofen and ibuprofen lysine, were physicochemically compatible with caffeine citrate injection. Caffeine base injection was physicochemically compatible with all 43 test drugs tested.

Physical compatibility of Xuebijing injection with 53 intravenous drugs during simulated Y-site administration

OBJECTIVE

Xuebijing injection (XBJ) is a commonly used herbal medicine injection in China. However, the physical compatibility of XBJ with other intravenous drugs remains unclear. The purpose of this research is to evaluate physical compatibility of Xuebijing injection (XBJ) with 53 intravenous drugs (including 31 Chinese medicine injections and 22 chemicals) during simulated Y-site administration.

METHODS

Y-site administration was simulated in vitro by admixing 0.33 ml/ml XBJ with an equal volume of other diluted 53 intravenous drugs, respectively. Physical compatibility including visual inspection, Tyndall beam, particle limits, turbidity, pH, chromacity value, spectroscopic absorption of 550 nm and 420 nm (A550 nm and A420 nm) were observed and assessed at 0, 1, 2, and 4 h. Physical compatibility was defined as all solutions with no color changes, no gas evolution, particulate formation and no Tyndall beam within 4 hours, turbidity changes <0.5 nephelometric turbidity unit (NTU) compared to 0 h, particle limits allowed by the Chinese Pharmacopoeia (Ch.P) 2020 edition, pH changes <10% compared to 0, chromacity value changes <200 compared to 0 h, or photometrical changes of A420 nm <0.0400 or A550 nm <0.0100 compared to 0 h.

RESULTS

XBJ was physically incompatible with 27 of the 53 intravenous drugs tested, 26 were compatible with XBJ for 4 h.

CONCLUSIONS

XBJ should not be simultaneously co-administered with 27 of the 53 intravenous drugs during simulated Y-site. If coadministration was inevitable, flushing tube with NS or D5W before and after infusion of XBJ was needed. Assessment included visual inspection, Tyndall beam, turbidity measurement, particle counts, pH measurement, chromacity value measurement and absorption of A550 nm were proved to be valid and robust for the quality control of infusion and compatibility of Chinese herbal injection.

Combination of a propofol emulsion with alpha-2 adrenergic receptor agonists used for multimodal analgesia or sedation in intensive care units: a physicochemical stability study

OBJECTIVES

To assess the physicochemical stability of the combination of a propofol emulsion with an alpha-2 (α2) adrenergic receptor agonist (α2A; clonidine or dexmedetomidine) under conditions mimicking routine practice in an intensive care unit or in multimodal analgesia procedures.

METHODS

We developed and validated three stability-indicating methods based on high-performance liquid chromatography with ultraviolet (HPLC-UV) detection. Eight different conditions per combination were evaluated in triplicate, with variations in the simulated, bodyweight-adjusted dose level and the drugs' flow rate. The drugs were mixed in clinically relevant concentrations and proportions and then stored unprotected from light, in clear glass vials at room temperature for 96 hours. At each sampling point, we assessed the chemical stability (the HPLC-UV drug level, pH, and osmolality) and physical compatibility (visual aspect, zeta potential (ZP), mean droplet diameter (MDD, Z-average) and polydispersity index (PDI)). We validated our stability findings in positive and negative control experiments.

RESULTS

Over the 96-hour test, the concentrations of propofol, clonidine and dexmedetomidine did not fall below 90% of the initial value, and the pH and osmolality were stable. The visual aspect of the mixed propofol emulsions did not change. The MDD remained below 500 nm (range 165-195 nm). The PDI was always below 0.4; 78.7% of the measurements were below 0.1 and 21.3% were between 0.1 and 0.4. The ZP measurements (-31.3 to -42.9 mV) suggested that the emulsion was stable. The MDD and PDI increased slightly at 96 hours under some conditions, which might indicate early destabilisation of the emulsion. Given that the MDD remained below 500 nm, these emulsions are compatible with intravenous administration.

CONCLUSIONS

Our results demonstrate the chemical and physical compatibility of propofol-α2 agonist mixtures at concentrations and in proportions representative of standard protocols when stored unprotected from light at room temperature for 96 hours.

Co-administration of Intravenous Drugs: Rapidly Troubleshooting the Solid Form Composition of a Precipitate in a Multi-drug Mixture Using On-Site Raman Spectroscopy

Intravenous drugs are often co-administrated in the same intravenous catheter line due to which compatibility issues, such as complex precipitation processes in the catheter line, may occur. A well-known example that led to several neonatal deaths is the precipitation due to co-administration of ceftriaxone- and calcium-containing solutions. The current study is exploring the applicability of Raman spectroscopy for testing intravenous drug compatibility in hospital settings. The precipitation of ceftriaxone calcium was used as a model system and explored in several multi-drug mixtures containing both structurally similar and clinically relevant drugs for co-infusion. Equal molar concentrations of solutions containing ceftriaxone and calcium chloride dihydrate were mixed with solutions of cefotaxime, ampicillin, paracetamol, and metoclopramide. The precipitate formed was collected as an "unknown" material, dried, and analyzed. Several solid-state analytical methods, including X-ray powder diffraction, Raman spectroscopy, and thermogravimetric analysis, were used to characterize the precipitate. Raman microscopy was used to investigate the identity of single sub-visual particles precipitated from a mixture of ceftriaxone, cefotaxime, and calcium chloride. X-ray powder diffraction suggested that the precipitate was partially crystalline; however, the identity of the solid form of the precipitate could not be confirmed with this standard method. Raman spectroscopy combined with multi-variate analyses (principal component analysis and soft independent modelling class analogy) enabled the correct detection and identification of the precipitate as ceftriaxone calcium. Raman microscopy enabled the identification of ceftriaxone calcium single particles of sub-visual size (around 25 μm), which is in the size range that may occlude capillaries. This study indicates that Raman spectroscopy is a promising approach for supporting clinical decisions and especially for compatibility assessments of drug infusions in hospital settings.

Urokinase-based lock solutions for catheter salvage: A case of an upcoming kidney transplant recipient

Catheter-related bloodstream infection (CRBSI) is a significant complication among patients on haemodialysis (HD) who are dependent on a central venous catheter (CVC) for an extended period. Catheter removal as first-line treatment can induce accelerated venous access site depletion in patients on HD who rely on it to survive. It is possible to retain the catheter in stable patients without septic syndrome while administering systemic antibiotics and antibiotic lock therapy. Herein, we report the case of a patient on HD with CRBSI who was successfully treated with intravenous levofloxacin- and urokinase-based antibiotic lock, without catheter removal prior to kidney transplantation. The use of urokinase in combination with antibiotics in lock solutions for treating catheter infections is rare. We verified the physical compatibility of levofloxacin and urokinase by visual inspection, turbidimetric measurements, and particle count. To our knowledge, this was a rare case demonstrating the effective use of urokinase and levofloxacin in a catheter lock for CRBSI in a patient on HD. Considering the need for highly concentrated antimicrobials and the availability of various antibiotics, the compatibility and stability of the lock solution is a matter of concern. Further studies are warranted to assess the stability and compatibility of various antibiotics in combination with urokinase.