Drug-induced electrolyte disorders

Incidence and physiological mechanism of carboplatin-induced electrolyte abnormality among patients with non-small cell lung cancer

To clarify the association between carboplatin and electrolyte abnormality, a pooled-analysis was performed with the adverse event reports of non-small cell lung cancer patients. A total of 19901 adverse events were retrieved from the FDA Adverse Event Reporting System (FAERS). Pooled reporting odds ratios (RORs) and 95% CIs suggested that carboplatin was significantly associated with hyponatremia (pooled ROR = 1.57, 95% CI 1.18-2.09, P = 1.99×10-3) and hypokalemia (pooled ROR = 2.37, 95% CI 1.80-3.10, P = 5.24×10-10) as compared to other therapies. In addition, we found that dehydration was frequently concurrent with carboplatin therapy (pooled ROR = 2.01, 95% CI 1.52-2.66, P = 8.37×10-7), which may prompt excessive water ingestion and decrease serum electrolyte concentrations. This information has not been mentioned in the FDA-approved drug label and could help explain the physiological mechanism of carboplatin-induced electrolyte abnormality. In conclusion, the above results will facilitate clinical management and prompt intervention of life-threatening electrolyte imbalance in the course of cancer treatment.

Electrolyte disturbances associated with commonly prescribed medications in the intensive care unit

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.

A composite screening tool for medication reviews of outpatients: general issues with specific examples

Regular performance of medication reviews is prominent among methods that have been advocated to reduce the extent and seriousness of drug-related problems, such as adverse drug reactions, drug-disease interactions, drug-drug interactions, drug ineffectiveness and cost ineffectiveness. Several screening tools have been developed to guide practising healthcare professionals and researchers in reviewing the medication patterns of elderly patients; however, each of these tools has its own limitations. This review discusses a wide range of general prescription-, treatment- and patient-related issues that should be taken into account when reviewing medication patterns by implicit screening. These include generic and therapeutic substitution; potentially superfluous or inappropriate medications; potentially inappropriate dosages or duration of treatment; drug-disease and drug-drug interactions; under-treatment; making use of laboratory test results; patient adherence, experiences and habits; appropriate dosage forms and packaging. A broad selection of specific examples and references that can be used as a basis for explicit screening of medication patterns in outpatients is also offered.

Magnesium deficiency may be an important determinant of ventricular ectopy in digitalised patients with chronic atrial fibrillation

Digitalised patients with chronic atrial fibrillation (AF) have a high prevalence of ventricular premature beats (VPB); magnesium deficiency may be a contributory factor. We have used a magnesium loading-test to examine the relationship between ventricular ectopy and magnesium status in 14 digitalised patients with chronic AF. Among seven patients with infrequent VPB (less than 250 24 h-1; mean 107 24 h-1) mean magnesium retention was 10.1% and four subjects retained no significant quantities of magnesium, indicating magnesium repletion. Among the remaining seven patients, mean magnesium retention was significantly higher (33.1%, P less than 0.02) and all patients retained 20% or more of the load given. There was an overall relationship between Mg retention and numbers of VPB (rs = 0.54; P less than 0.05). Magnesium deficiency may be determinant of ventricular ectopy in digitalised patients with chronic AF.

Oral magnesium reduces ventricular ectopy in digitalised patients with chronic atrial fibrillation

We have examined the effects of magnesium replacement therapy upon post-exercise heart rate and incidence of ventricular premature beats (VPB) in digitalised patients with AF. In 11 such patients, all of whom had serum magnesium concentrations of less than 0.85 mmol/l, treatment with magnesium glycerophosphate was associated with a significant reduction in number of VPBs (982 v. 416 VPB/24 h). Five patients had a high prevalence of ventricular ectopy (greater than 300 VPB/24 h) and these subjects showed particularly marked decreases in VPBs during magnesium treatment (1998 v. 690 VPB/24 h). Three patients had slightly increased QTc intervals but these did not change during magnesium replacement. No significant changes were seen in the mean post-exercise heart rate although 2 subjects did show falls of 25% or more during magnesium replacement. We conclude that treatment with magnesium glycerophosphate may be associated with a decreased prevalence of ventricular ectopy in some digitalised patients with chronic AF and mild-moderate hypomagnesaemia.

A key to the literature of total parenteral nutrition: update 1987

This comprehensive bibliography is intended to enhance the education of the practitioner, student, and academician in the area of parenteral nutrition. This bibliography is not all-inclusive but serves as an update from the original published in 1983. Of particular note in this work is the addition of topics that reflect a growing interest in medical specialties with regard to patient nutritional status and support.

Hypomagnesemia associated with gentamicin therapy

Two patients developed symptomatic hypomagnesemia most likely secondary to gentamicin therapy. Both patients were on regular doses of the antibiotic and had hypokalemia and hypocalcemia secondary to hypomagnesemia. Mechanisms postulated for the occurrence of hypomagnesemia secondary to gentamicin therapy include drug-induced hyperaldosteronism and tubular toxicity. Patients on gentamicin therapy should have serum magnesium, calcium, and potassium levels monitored routinely.