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Biomedical subjects

D C McLeod

Publications and source records attributed to D C McLeod.

At least 37 records · Page 2Linked to original sources
PubMed1983

Comparative effects and analgesic efficacy of the agonist-antagonist opioids.

Pentazocine, butorphanol, nalbuphine, and buprenorphine are mixed agonist-antagonist opioids that are effective analgesics, with less abuse potential than the agonists morphine, propoxyphene, and codeine. The dual properties of the agonist-antagonists are largely explained by their varying actions at the postulated three types (mu, chi, and sigma) of opioid receptors. The agonist-antagonists are classified as either morphine-like or nalorphine-like, based on their acute effects and withdrawal symptoms after chronic dosing. Buprenorphine is morphine-like, while the other drugs are nalorphine-like. These agents vary in the duration of analgesia, with pentazocine having a mean action of three hours and buprenorphine greater than six hours. The hemodynamic effects of nalbuphine and buprenorphine generally resemble those of morphine, while pentazocine and butorphanol increase cardiac workload, blood pressure, and pulmonary artery pressure. The agonist-antagonists have ceilings for respiratory depression, whereas the agonists produce dose-dependent depression. Agonist-antagonists generally produce less increase in biliary ductal pressure than does morphine. The major clinical limitations are that agonist-dependent patients may experience unpleasant subjective effects, when treated with the agonist-antagonists, and the nalorphine-like agents can produce psychotomimetic effects. More clinical experience is needed to rank the abuse potential within this group of opioids. The newer agents are being studied for oral use in acute and chronic pain.

Analgesics↗
PubMed1982

Effect of urinary acidifiers on formaldehyde concentration and efficacy with methenamine therapy.

Twenty-seven patients with indwelling urinary catheters and chronic bacteriuria were studied for methenamine efficacy. In a crossover fashion, each patient received methenamine mandelate granules 4 g/day alone, with ascorbic acid 4 g/day, and with ascorbic acid 4 g/day plus cranberry cocktail one 1/day. Proteus vulgaris, Pseudomonas aeruginosa, and E. coli were the common pathogens. Urinary acidifiers had no significant effect on mean urine pH, however, high urinary formaldehyde concentrations were associated with the use of ascorbic acid. Bacteriocidal formaldehyde levels were more frequently present in patients with acidic urine pH than those with alkaline pH. Although ascorbic acid increased formaldehyde levels, additional cranberry cocktail had no further effect. Despite higher formaldehyde levels, urine culture results were positive in most cases with or without urine acidification. Methenamine therapy may be of limited value in asymptomatic chronic bacteriuric patients with indwelling catheters.

Aged↗
PubMed1981

Evaluation of the clinical use of serum digoxin radioimmunoassays.

Of 2,586 consecutive patients admitted to a private general teaching hospital, 370 (14 percent) received digoxin therapy. Serum digoxin assays were performed on 261 of these 370 subjects. In a representative sample of 97 patients, 61 attending physicians were responsible for their care. The mean and median age of the patients was 70 years (range, 39-96 years), and one-quarter of them had a significant degree of renal impairment. Sixty-one percent of the patients were being treated for congestive heart failure (CHF), and the remainder for atrial fibrillation with or without CHF. Overall, 67 percent of the serum digoxin assays were judged to be appropriate, particularly those requested for evaluation of possible digitalis toxicity or the dosage in renal impairment, but only 43 percent of the assays used to assess maintenance therapy or the patient's compliance were deemed appropriate. A significant difference was found in the percentage of appropriate assays useful by the physicians, as compared to the percentage of inappropriate assays. Inappropriate serum digoxin assays cost about $30,000 annually in this 680-bed hospital. Stricter criteria for admission assays would eliminate much of this excessive usage.

Adult↗
PubMed1981

Predictability of methenamine efficacy based on type of urinary pathogen and pH.

This study involved 27 geriatric patients with asymptomatic chronic bacteriuria; all had indwelling Foley catheters. The treatment regimens (daily oral dosage) were: methenamine mandelate (MM) granules, 4 gm; MM, 4 gm, plus ascorbic acid, 4 gm; and MM, 4 gm, plus ascorbic acid, 4 gm, plus cranberry cocktail, 1 liter--administered according to a cross-over design. Proteus vulgaris, Pseudomonas aeruginosa and E. coli were the most common urinary organisms. Proteus organisms were more often found in alkaline than in acidic urines, but the type of pathogen had no influence on urinary pH. Urinary formaldehyde concentration [HCHO] was lower in patients with Proteus infection (17.7 micrograms/ml) than in those with Pseudomonas (21.9 micrograms/ml) or E. coli infection (21.8 micrograms/ml). However, for Proteus infection, [HCHO] was higher in patients receiving MM plus ascorbic acid than in those receiving MM alone. Addition of cranberry cocktail to ascorbic acid did not enhance urinary pH, [HCHO] or methenamine efficacy. Our data suggest that in Foley catheter patients with chronic asymptomatic bacteriuria secondary to Proteus, Pseudomonas or E. coli infection, the type of urinary pathogen or the urinary pH cannot be used to predict the efficacy of methenamine therapy either with or without urinary acidifying agents.

Aged↗
PubMed1980

Lack of effect of ascorbic acid, hippuric acid, and methenamine (urinary formaldehyde) on the copper-reduction glucose test in geriatric patients.

Ascorbic acid and hippuric acid (from cranberry juice) are commonly used to acidify the urine for the purpose of enhancing the degradation of therapeutic methenamine mandelate to urinary formaldehyde. A study was made of 27 nondiabetic geriatric patients with indwelling Foley catheters and chronic bacteriuria who were treated with methenamine mandelate (4 gm), ascorbic acid (4 gm), and cranberry cocktail (1 liter) daily. All of 972 urine samples showed formaldehyde in mean concentrations between 14 and 25 microgram/ml. No glucose was found when the urine was tested by the copper-reduction method. In vitro false positive reactions reported in the literature do not appear to be duplicated as an in vivo problem.

Aged↗
PubMed1978

Comparison of selected intravenous infusion pumps and rate regulators.

Selected intravenous infusion pumps and rate regulators were compared to determine the relative advantages and disadvantages and to formulate guidelines for purchase of these devices. Three basic types of devices were studied: infusion rate regulators, nonvolumetric (peristaltic) infusion pumps and volumetric infusion pumps. Simple syringe-type infusion pumps were not studied. After use and close study of the devices, both in the laboratory and in the clinical area, desirable features were identified. Ideally, the infusion device should operate over a wide rate range, use standard administration sets, be easy to assemble and service, have an internal battery of good power for several hours, have appropriate malfunction alarms, have an automatic keep-open device in alarm situations, be accurate under a variety of situations, and be easy for the nurse to understand and operate. All devices tested were accurate within the limits claimed by the manufacturer, although a couple of models have features which can cause gross volume errors. Overall evaluation resulted in preference of some devices over others. Cost of infusion devices and administration sets can vary widely, and this should be a factor in the final choice of intravenous infusion equipment.

Evaluation Studies as Topic↗
PubMed1978

Use of a pharmacy technologist to manage technicians' activities.

The role of a pharmacy technologist, in comparison with that of a pharmacist and a pharmacy technician, is discussed as it was developed at one hospital. Training, staffing patterns, personnel functions, acceptance and salary of the technologist are described. The use of the technologist to manage technician-level personnel is suggested as a means of providing the pharmacist with more time for professional activities.

Hospital Bed Capacity, 500 and over↗
PubMed1976

Clinical pharmacy: the past, present and future.

Clinical pharmacy is discussed in terms of its historical basis, current status and future trends. Topics covered include the origins and current scope of clinical pharmacy practice, controversial issues in clinical pharmacy practice and education, and the quest for quality in clinical pharmacy practice.

Education, Pharmacy↗