Trending Topics in Health-System Pharmacy
Removing unnecessary penicillin allergy labels
In a recent article in the American Journal of Respiratory Critical Care Medicine, Stone and colleagues at Vanderbilt University Medical Center showed that patients with a penicillin allergy label but low allergy risk can be given oral amoxicillin without developing an immediate or delayed allergic reaction. It’s estimated that up to 15% of U.S. patients are labeled as penicillin allergic, but many of these labels may be the result of an inaccurate diagnosis. These patients may be unnecessarily prescribed an antibiotic that is not the most effective for their particular infection.
The researchers developed a tool based on risk stratification of patients in a drug allergy testing clinic. Patients were classified as low risk if they had developed hives after penicillin treatment more than 5 years previously and had a self-limited rash, GI symptoms only, a remote childhood history, a family history only, avoidance from fear of allergy only, a known tolerance to penicillin since the reported reaction, or nonallergic symptoms.
Over the next 7 months, patients admitted to the ICU with a penicillin allergy label were evaluated for penicillin allergy risk. Of these, 68 patients met the criteria for low risk, and 54 patients agreed to a single oral dose of 250 mg amoxicillin and were observed for 1 hour. None of the patients had either an immediate or a delayed reaction, and their penicillin allergy label was removed. Subsequently, 41 of the 54 participants received multiple doses of either penicillin or cephalosporin without reaction, confirming the results of the initial dose.
Timing matters in antithrombotic therapy
In the AUGUSTUS study, a global group of researchers led by clinicians at the Duke Clinical Research Institute studied antithrombotic therapy in patients after acute coronary syndrome (ACS) and/or undergoing percutaneous coronary intervention (PCI) treated with a P2Y12 inhibitor in atrial fibrillation.
They found that in these patients, an antithrombotic regimen that included apixaban without aspirin resulted in less bleeding and fewer hospitalizations than regimens that included a vitamin K antagonist (VKA), aspirin, or both. However, the number of ischemic events was numerically higher in patients who had received the placebo.
In a follow-up study published recently in Circulation, a group of the original researchers assessed the trade-off of risk (bleeding) and benefit (fewer ischemic events) over time with apixaban versus a VKA and aspirin versus placebo.
The post-hoc analysis compared the risk of three composite bleeding outcomes and three composite ischemic outcomes from randomization through 30 days and from 30 days to 6 months with apixaban and VKA and with aspirin and placebo.
In patients with atrial fibrillation and recent ACS and/or PCI receiving a P2Y12 inhibitor, the researchers found that apixaban is preferred over VKA. Use of aspirin acutely and for up to 30 days results in an equal tradeoff between an increase in severe bleeding and reduction in severe ischemic events. After 30 days, aspirin continued to increase bleeding without significantly reducing ischemic events.
These findings should inform clinicians and patients in making shared, patient-centric, evidence-based decisions about antithrombotic therapy.
Saline vs. lactated Ringer’s solutions in surgery
Both saline and lactated Ringer’s solutions are commonly given to surgical patients for drug administration and vascular volume repletion. However, because saline solution has a much higher chloride concentration than human plasma, hyperchloremic acidosis consequent to saline administration may provoke complications.
Researchers at the Cleveland Clinic conducted an alternating cohort-controlled trial in which adults having colorectal and orthopedic surgery were given either lactated Ringer’s solution or normal saline in 2-week blocks between September 2015 and August 2018 to investigate whether use of saline solution resulted in increased in-hospital mortality and major postoperative complications compared with use of lactated Ringer’s solution.
The study, published recently in Anesthesiology, involved 8,616 qualifying elective orthopedic and colorectal surgery patients, each receiving a median 1.9 l of fluid. The researchers found no clinically meaningful difference in postoperative complications with lactated Ringer’s or saline volume replacement. Thus, either normal saline or lactated Ringer’s solution is a reasonable intraoperative fluid choice for patients who are undergoing colorectal or orthopedic surgery.
To sedate or not to sedate
Sedation of patients on a mechanical ventilator has been commonly used for many years. However, published research has indicated that use of sedatives may worsen outcomes in mechanically ventilated patients.
Scandinavian researchers led by Palle Toft, MD, at Odense University Hospital conducted a recent trial to investigate whether a plan of no sedation in patients receiving mechanical ventilation would result in a better survival outcome than a plan of light sedation with daily interruption.
The study, published recently in the New England Journal of Medicine (NEJM), used a multicenter, randomized controlled trial in which mechanically ventilated ICU patients were assigned in a 1:1 ratio to no sedation or light sedation (i.e., to a level at which the patient was arousable) with daily interruption. The primary outcome was mortality at 90 days.
Study results indicated that among mechanically ventilated ICU patients, mortality at 90 days did not differ significantly between those assigned to a plan of no sedation and those assigned to a plan of light sedation with daily interruption.
However, patients with no sedation had significantly higher accidental self-extubation that required reintubation within 24 hours compared with patients receiving light sedation.
In a comment on the study published in NEJM Journal Watch Hospital Medicine, Daniel D. Dressler, MD, professor of medicine at Emory University School of Medicine, said, “Although some patients might tolerate nonsedation during invasive mechanical ventilation, it can lead to more ‘active’ or alert patients, possibly contributing to the higher rate of self-extubations.
For this reason, this study should not necessarily change current practice of light sedation with at least daily interruptions for most ventilated patients.”
Correction
In the April 2020 Health-System Edition of Pharmacy Today, an article summarizing the 2019 AHA/ASA guidelines incorrectly stated that updated guidelines removed blood pressure targets prior to use of fibrinolytic treatment for acute ischemic stroke. However, this recommendation remains unchanged from the previous guideline, which states that patients with acute ischemic stroke who are eligible for treatment with I.V. rtPA should have their blood pressure carefully lowered to less than 185/110 mm Hg before fibrinolytic therapy is initiated.