Sodium Zirconium Cyclosilicate (ZS-9): A Novel Agent for the Treatment of Hyperkalemia

Hyperkalemia is a potentially life-threatening electrolyte abnormality that may be caused by select medications, underlying organ dysfunction, or alterations in potassium homeostasis. Treatment for this condition has remained largely unchanged since the release of sodium polystyrene sulfonate (SPS) in 1958. Despite its widespread use, the safety and efficacy of SPS remains controversial. Two novel potassium-binding resins have emerged in recent years. Patiromer was the first of these to receive U.S. Food and Drug Administration approval for the treatment of hyperkalemia in October 2015. A second potassium-binding resin, a zirconium cyclosilicate currently known as ZS-9, may provide yet another alternative to the archetypal treatment with SPS. ZS-9 is an orally administered nonabsorbed inorganic compound that selectively binds potassium ions in vivo. Two phase III multicenter, randomized, placebo-controlled, double-blind trials have evaluated ZS-9 for the treatment of acute hyperkalemia. In this review, we discuss the pharmacology, clinical efficacy, safety, and potential place in therapy of ZS-9 for the enhanced elimination of potassium in the setting of hyperkalemia.

Risk factors for allergic rhinitis in Costa Rican children with asthma

BACKGROUND

Risk factors for allergic rhinitis (AR) in asthmatics are likely distinct from those for AR or asthma alone. We sought to identify clinical and environmental risk factors for AR in children with asthma.

METHODS

We performed a cross-sectional study of 616 Costa Rican children aged 6-14 years with asthma. Candidate risk factors were drawn from questionnaire data, spirometry, methacholine challenge testing, skin testing, and serology. Two outcome measures, skin test reaction (STR)-positive AR and physician-diagnosed AR, were examined by logistic regression.

RESULTS

STR-positive AR had high prevalence (80%) in Costa Rican children with asthma, and its independent risk factors were nasal symptoms after exposure to dust or mold, parental history of AR, older age at asthma onset, oral steroid use in the past year, eosinophilia, and positive IgEs to dust mite and cockroach. Physician-diagnosed AR had lower prevalence (27%), and its independent risk factors were nasal symptoms after pollen exposure, STR to tree pollens, a parental history of AR, inhaled steroid and short-acting beta2 agonist use in the past year, household mold/mildew, and fewer older siblings. A physician's diagnosis was only 29.5% sensitive for STR-positive AR.

CONCLUSIONS

Risk factors for AR in children with asthma depend on the definition of AR. Indoor allergens drive risk for STR-positive AR. Outdoor allergens and home environmental conditions are risk factors for physician-diagnosed AR. We propose that children with asthma in Costa Rica and other Latin American nations undergo limited skin testing or specific IgE measurements to reduce the current under-diagnosis of AR.

Stability of high-dose insulin in normal saline bags for treatment of calcium channel blocker and beta blocker overdose

CONTEXT

High-dose insulin has become a first-line therapy for treating severe calcium channel blocker and beta blocker toxicity. Insulin infusions used to treat other conditions (e.g., diabetic ketoacidosis) may be used, but this may lead to pulmonary compromise due to fluid volume overload. An obvious solution would be to use a more concentrated insulin infusion; however, data describing the stability of insulin in polyvinyl chloride bags at concentrations >1 unit/mL are not readily available.

OBJECTIVE

To determine the stability of insulin at 16 units/mL in 0.9% saline solution.

MATERIALS AND METHODS

Eight-hundred units of regular insulin (8 mL from a stock vial containing 100 units/mL) were added to 42 mL of 0.9% saline solution in a polyvinyl chloride bag to make a final concentration of 16 units/mL. Two bags were stored at 4 °C (refrigerated) and two at 25 °C (room temperature). Samples were withdrawn and tested for insulin concentration periodically over 14 days.

RESULTS

Concentrated regular insulin in a polyvinyl chloride bag remained within 90% of equilibrium concentration at all time points, indicating the 16 units/mL concentration was sufficiently stable both refrigerated and at room temperature for 14 days.

DISCUSSION

Administration of high-dose insulin can cause fluid volume overload when using traditional insulin formulations. The 16 units/mL concentration allows for the treatment of a patient with severe calcium channel blocker or beta blocker toxicity for a reasonable period of time without administering excessive fluid.

CONCLUSION

Insulin at a concentration of 16 units/mL is stable for 14 days, the maximum timeframe currently allowed under US Pharmacopeia rules for compounding of sterile preparations. This stability data will allow institutions to issue beyond-use dating for intravenous fluids containing concentrated insulin and used for treating beta blocker and calcium channel blocker toxicity.

Effect of a Law Requiring Prescription Drug Monitoring Program Use on Emergency Department Opioid Prescribing: A Single-Center Analysis

OBJECTIVE

To compare opioid prescribing behavior of emergency medicine providers following the enactment of Connecticut Public Act (PA) 15-198 at a large academic tertiary medical center.

METHODS

This study is a single-center pre and postlaw retrospective cohort of ED patients discharged with opioid prescriptions. Patients discharged from January 1, 2015, to June 30, 2015, were analyzed as the prelaw cohort, and patients discharged from January 1, 2016, to June 30, 2016, were analyzed as the postlaw cohort. The primary outcome was the cumulative dose of solid dosage forms of opioids per prescription, calculated in morphine milligram equivalents (MME).

RESULTS

A total of 10,307 prescriptions included in the final analysis. A statistically significant decrease in the primary outcome was seen in the postlaw cohort compared with the prelaw cohort, respectively (75 MME [interquartile range, IQR: 60-100) vs 80 MME [IQR: 75-150]; P < .001). The postlaw cohort also saw 1289 (22.2%) fewer opioid prescriptions, primarily driven by a reduction in the number of schedule II opioids prescribed. In a posthoc analysis, the primary outcome remained statistically significant even when opioid prescriptions were only included if their prebuilt settings were unchanged between pre and postlaw cohorts, respectively (85.1%; 95.6 MME (±56.0); n = 5041 vs 86.7 MME (±39.6); n = 3713; P < .001).

CONCLUSIONS

The passage of PA 15-198 was associated with a decrease in the cumulative dose of opioids per prescription of solid dosage form products. This drop was precipitated by a transition from using opioids in schedule II to opioids in schedule IV and a modest decrease in prescribed opioid quantity.

Facial eschar following a single application of black salve

A previously healthy 86-year-old male was transported by ambulance to the trauma bay of the emergency department (ED) for profuse bleeding from the left temple. The ambulance crew raised concern that the volume and force of the bleed may suggest arterial involvement. The patient reported having applied a natural topical remedy to a mole two weeks prior at the recommendation of a naturopath. The patient described progressive blackening and swelling of the area in the days following the single application of the product. After gaining control of the bleeding in the ED, the area was found to have a raised, 2 cm eschar.

Acute Medication Poisoning

Poisoning is the leading cause of injury-related morbidity and mortality in the United States. The highest rates of exposure to poisons occur in children five years and younger, but opioid overdoses in young adults account for most deaths from poisonings in recent years. Intentional or accidental medication poisoning should be considered when evaluating patients with mental status changes, vital sign abnormalities, seizures, and gastrointestinal or cardiovascular problems. For all poisoned patients, a comprehensive history and physical examination are needed. Knowledge of toxidromes may help identify the cause in unknown ingestions; however, their usefulness may be limited when multiple toxins are ingested. Electrocardiography is indicated in patients reporting chest pain and dyspnea and in overdoses of beta blockers, tricyclic antidepressants, and antidysrhythmics. Measurement of electrolyte, serum creatinine, and serum bicarbonate levels and calculation of the anion gap may be helpful based on the clinical presentation. Treatment of a patient with acute poisoning is based on resuscitation and stabilization with a focus on airway, breathing, and circulation. When poisoning is suspected, the Poison Control provides health care workers and the public with access to a specialist 24 hours a day.

Prevalence of enamel defects and MIH in non-fluoridated and fluoridated communities

AIM

This was to study the prevalence of enamel defects and molar incisor hypomineralisation (MIH) in children attending Leeds Dental Institute (UK) and Westmead Dental Hospital, Sydney (Australia).

METHODS

Prospective dental examinations were carried out on 25 children referred to two orthodontic departments. A questionnaire was completed to obtain background information and about previous fluoride (F) exposure followed by an oral examination. First permanent molars and permanent incisors were examined for presence, type and severity of enamel defects using the modified DDE screening index. Chi square tests were used to compare results.

RESULTS

Data for 24 children in Sydney and 20 in Leeds presented with at least one enamel defect. Of 300 teeth examined, 155 in Sydney and 82 in Leeds had a defect (p < 0.005). Severity of enamel defects was higher in Sydney. The children presenting with any type of enamel defect in at least one incisor or molar were 21 in Sydney and 10 in Leeds. However, if only demarcated defects were considered, the number in Sydney dropped to 11 and in Leeds remained at 10.

CONCLUSIONS

There was a higher prevalence of enamel defects in those children living in F Sydney than in non-F Leeds, but the prevalence of MIH was the same supporting the view that F is not associated with the aetiology of MIH.