Mitchell S. Buckley

Electrolyte imbalances are common in critically ill patients. Although multiple disease states typically encountered in the intensive care unit may be responsible for the development of electrolyte disorders, medications may contribute to these disturbances as well. Medications can interfere with the absorption of electrolytes, alter hormonal responses affecting homeostasis, as well as directly impact organ function responsible for maintaining electrolyte balance. The focus on this review is to identify commonly prescribed medications in the intensive care unit and potential electrolyte disturbances that may occur as a result of their use. This review will also discuss the postulated mechanisms associated with these drug-induced disorders. The specific drug-induced electrolyte disorders discussed in this review involve abnormalities in sodium, potassium, calcium, phosphate, and magnesium. Clinicians encountering electrolyte disturbances should be vigilant in monitoring the patient's medications as a potential etiology. Insight into these drug-induced disorders should allow the clinician to provide optimal medical management for the critically ill patient, thus improving overall healthcare outcomes.

OBJECTIVE: To report a case of elevated international normalized ratio (INR) in a patient taking fish oil and warfarin. CASE SUMMARY: A 67-year-old white woman had been taking warfarin for 1(1/2) years due to recurrent transient ischemic attacks. Her medical history included hypothyroidism, hyperlipidemia, osteopenia, hypertension, and coronary artery disease. She also experienced an inferior myocardial infarction in 1995 requiring angioplasty, surgical repair of her femoral artery in 1995, and hernia repair in 1996. This patient has her INR checked in the anticoagulation clinic and is followed monthly by the clinical pharmacist. Prior to the interaction, her INR was therapeutic for 5 months while she was taking warfarin 1.5 mg/d. The patient admitted to doubling her fish oil dose from 1000 to 2000 mg/d. Without dietary, lifestyle, or medication changes, the INR increased from 2.8 to 4.3 within 1 month. The INR decreased to 1.6 one week after subsequent fish oil reduction, necessitating a return to the original warfarin dosing regimen. DISCUSSION: Fish oil supplementation could have provided additional anticoagulation with warfarin therapy. Fish oil, an omega-3 polyunsaturated fatty acid, consists of eicosapentaenoic acid and docosahexaenoic acid. This fatty acid may affect platelet aggregation and/or vitamin K-dependent coagulation factors. Omega-3 fatty acids may lower thromboxane A(2) supplies within the platelet as well as decrease factor VII levels. Although controversial, this case report illustrates that fish oil can provide additive anticoagulant effects when given with warfarin. CONCLUSIONS: This case reveals a significant rise in INR after the dose of concomitant fish oil was doubled. Patients undergoing anticoagulation therapy with warfarin should be educated about and monitored for possible drug-herb interactions. Pharmacists can play a crucial role in identifying possible drug interactions by asking patients taking warfarin about herbal and other alternative medicine product use.

INTRODUCTION: Incorporation of clinical decision support systems (CDSSs) into computerized physician order entry assists prescribers with medication dosing, identification of duplicate therapies, drug-allergy alerts and drug-drug interactions (DDIs). The generation of DDI alerts is one aspect of CDSS that may improve patient safety and reduce adverse drug events. AREAS COVERED: Currents issues with the generation of DDI alerts, such as alert fatigue, unclear clinical significance and database inconsistencies are a few of the problems that have been identified with DDI alerting. Research has shown that DDI alerting may be improved through the tiering of alerts, generation of patient-specific alert and directing some alerts to clinicians other than physicians. More research in this area, such as how to decrease the variability of database rating systems, improve the identification of clinically significant alerts and increase the patient specificity of the generated DDI alerts, should be conducted. EXPERT OPINION: DDI knowledgebases need to take into account more patient-specific information. Strategies to avoid alert fatigue, such as DDI tiering and reducing signal:noise ratios, are important areas for future study. End-user participation and clinician feedback should be incorporated in the development of DDI knowledgebases to increase alert compliance.

Opioids are the cornerstone of pain management; however, their use is associated with a variety of adverse drug events (ADEs) ranging from nausea and vomiting to urinary retention and respiratory depression. The purpose of this review is to describe the frequency and cost associated with different types of opioid-related ADEs to better understand their economic impact. A search of studies published in journals from 1946 to December, 2013, was conducted using MEDLINE and EMBASE. A total of 20 articles were reviewed. Data reflect a substantial economic burden of opioid-related ADEs resulting in high hospital costs, prolonged hospital stays, and substantial health care resource usage. Nausea, vomiting, and constipation are frequent and increased costs occur in all types of pain (surgical, nonsurgical, cancer, noncancer) in both inpatients and outpatients. Given the large economic burden of opioid-related ADEs, prevention rather than treatment may be the most effective strategy.

OBJECTIVE: To determine the incidence, type, and stage of occurrence of medication errors and potential and actual adverse drug events (ADEs) in a pediatric intensive care unit (ICU) using trained observers. The preventability and severity of ADEs and the system failures leading to medication error occurrence were also investigated. DESIGN: Prospective, direct observation study. SETTING: A 16-bed pediatric medical/surgical ICU at a tertiary care academic medical center. PATIENTS: One enrolled nurse caring for at least one pediatric ICU patient age <18 yrs was randomly chosen during each observation period. INTERVENTIONS: Observers would intervene only in the event that the medication error would cause substantial patient harm or discomfort. MEASUREMENTS AND MAIN RESULTS: Medication errors and potential and actual ADEs were identified throughout the entire medication use process. The 26 12-hr observation periods included 357 reviewed written orders and 263 observed doses. The study observers identified 58 incidents, which were subsequently classified by the evaluators according to clinical importance, severity, and preventability. Fifty-two of these incidents were considered medication errors; six incidents were determined to be nonpreventable ADEs. Of the 52 medication errors, 42 (81%) were considered clinically important. Potential ADEs comprised 35 (83%) of these important medication errors; the other seven (17%) were classified as actual, preventable ADEs. Overall, the actual and potential ADE rate occurred at 3.6 events and 9.8 events per 100 orders, respectively. CONCLUSIONS: Our medication error rate was similar to that of previous pediatric ICU studies that used the direct observation method for reporting but higher than the rates in previous studies using other detection techniques such as voluntary incident reporting. Periodic direct observation and other ongoing data collection methods such as voluntary incident reporting have the potential to be complementary approaches to medication error and ADE detection.