A new method for the determination of inulin in plasma and urine

Background Elderly patients are vulnerable to drug interactions because of age-related physiologic changes, an increased risk for disease associated with aging, and the consequent increase in medication use. Objective The purpose of this narrative review was to describe findings from rigorously designed observational cohort and case-control studies that have assessed specific drug interactions in elderly patients. Methods The PubMed and International Pharmaceutical Abstracts databases were searched for studies published in English over the past 10 years (December 2000–December 2010) using relevant Medical Subject Headings terms ( aged; aged, 80 and over; and drug interactions ) and search terms ( drug interaction and elderly ). Search strategies were saved and repeated through September 2011 to ensure that the most recent relevant published articles were identified. Additional articles were found using a search of review articles and reference lists of the identified studies. Studies were included if they were observational cohort or case-control studies that reported specific adverse drug interactions, included patients aged ≥65 years, and evaluated clinically meaningful end points. Studies were excluded if they used less rigorous observational designs, assessed pharmacokinetic/pharmacodynamic properties, evaluated drug-nutrient or drug-disease interactions or interactions of drug combinations used for therapeutic benefit (eg, dual antiplatelet therapy), or had inconclusive evidence. Results Seventeen studies met the inclusion criteria. Sixteen studies reported an elevated risk for hospitalization in older adults associated with adverse drug interactions. The drug interactions included: angiotensin-converting enzyme (ACE) inhibitors and potassium-sparing diuretics, ACE inhibitors or angiotensin receptor blockers and sulfamethoxazole/trimethoprim, benzodiazepines or zolpidem and interacting medications, calcium channel blockers and macrolide antibiotics, digoxin and macrolide antibiotics, lithium and loop diuretics or ACE inhibitors, phenytoin and sulfamethoxazole/trimethoprim, sulfonylureas and antimicrobial agents, theophylline and ciprofloxacin, and warfarin and antimicrobial agents or nonsteroidal anti-inflammatory drugs. One study reported the risk for breast cancer-related death as a function of paroxetine exposure among women treated with tamoxifen. Conclusions Several population-based studies have reported significant harm associated drug interactions in elderly patients. Increased awareness and interventions aimed at reducing exposure and minimizing the risks associated with potentially harmful drug combinations are needed.

Potentially harmful drug-drug interactions in the elderly: a review.

Background: Changes in routine clinical chemical indicators of renal function in the hypothyroid state are not well characterized, and are infrequently discussed in standard internal medicine or subspeciality textbooks. Patients and Methods: We evaluated 24 consecutive patients with iatrogenic hypothyroidism induced prior to radioiodine scanning for monitoring of thyroid carcinoma. Serum creatinine and thyroid function tests were measured prior to, during, and subsequent to the period of induced hypothyroidism. Results: Among 29 episodes with paired prior euthyroid and hypothyroid serum creatinine values, the hypothyroid value was greater in 26 (89.7%), and equal in 3 (10.3%), less in none; the mean hypothyroid value was significantly greater (103 vs 76 μmol/L [1.17 vs 0.87 mg/ dL]) (P<.001). Among 36 episodes with paired hypothyroid and subsequent euthyroid serum creatinine values, the hypothyroid value was greater in 33 (91.7%), equal in 2 (5.6%), and less in 1 (2.8%); the mean hypothyroid value was again significantly greater (102 vs 75 μmol/L [1.15 vs 0.85 mg/dL]) (P<.001). There was no significant difference between prior and subsequent euthyroid serum creatinine values. Serum creatinine values above the stated normal range occurred in 6 of 36 hypothyroid episodes. Conclusions: There is a consistent and reversible elevation of serum creatinine values in the hypothyroid state. Frankly abnormal serum creatinine levels will occur in some cases.

/pdf/consistent-reversible-elevations-of-serum-creatinine-levels-33smjw8og1.pdf

Consistent Reversible Elevations of Serum Creatinine Levels in Severe Hypothyroidism

Background
Criteria to assess the appropriateness of prescriptions might serve as a helpful guideline during professional training and in daily practice, with the aim to improve a patient’s pharmacotherapy.

/pdf/inappropriate-prescribing-a-systematic-overview-of-published-48yq9xsp5d.pdf

Inappropriate prescribing: a systematic overview of published assessment tools.

https://www.kidney-international.org/article/S0085-2538(15)31389-2/pdf

The thyroid and the kidney

An improved method has been developed for the measurement of salicylic acid and salicyluric acid in blood plasma and for these two substances and salicyl glycuronates in urine. Older methods measured salicyluric acid by the different extraction efficiencies of two solvents and the weaker color formation of salicyluric acid with ferric nitrate. This method measures salicyluric acid more specifically by means of its marked fluorescence at p H 10. A low concentration of a fluorescent substance, probably salicyluric acid, which has not been reported previously was found in dog plasma following large doses of sodium salicylate. The rate of hydrolysis of salicyluric acid by concentrated hydrochloric acid, an important factor in the calculation of the salicyl glycuronate fraction in this and former methods, has been re-examined and a higher value than previously reported has been found. An explanation of this difference is suggested. A synthetic sample of the glycuronate of salicylic acid coupled through the phenolic hydroxyl group, which has not been isolated from urine in pure form, has been tested for reactivity in the method.

Determination of salicylic acid and two metabolites in plasma and urine using fluorimetry for directly measuring salicyluric acid.

A modified diphenylamine procedure for the determination of inulin.

DESPITE the considerable interest that exists in the cardiovascular abnormalities associated with myxedema, little can be found in the literature regarding renal function in this disorder. Corcoran and Page reported renal function studies on 2 patients suffering from myxedema, which demonstrated a reduction in renal blood flow, glomerular filtration, and tubular secretory capacity (1). The data of Beaumont and Robertson (2) indicate that urea clearance is depressed in myxedema, but that no change occurs in the concentrating ability of the kidneys. The purpose of this paper is to present the results of glomerular filtration rate and effective renal plasma flow in 7 myxedematous patients. METHOD Specific clearance methods were used on 7 patients with untreated myxedema,1 to Study the rate of glomerular filtration, the renal plasma flow, the filtration fraction, and the renal blood flow. Inulin clearances (CIN) were measured to determine the rate of glomerular filtration, and measurements of plasma p-aniinoh...

Renal clearance in patients with myxedema.

Effect of pitressin on the urinary excretion of chloride and water in the human.

https://www.gastrojournal.org/article/S0016-5085(49)80032-1/pdf

J. Maxwell Little

Papers

Determination of salicylic acid and two metabolites in plasma and urine using fluorimetry for directly measuring salicyluric acid.

A modified diphenylamine procedure for the determination of inulin.

Renal clearance in patients with myxedema.

Effect of pitressin on the urinary excretion of chloride and water in the human.

The use of tetraethylammonium chloride in the treatment of patients with peptic ulcer.