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Biomedical subjects

S H Jackson

Publications and source records attributed to S H Jackson.

At least 37 records · Page 2Linked to original sources
PubMed1997

Development of prescribing indicators for elderly medical inpatients.

AIMS: To identify and improve suboptimal prescribing for elderly patients we have developed a number of prescribing indicators which focus on areas of concern and allow evaluation of the benefit of interventions. We report here on fourteen indicators. METHODS: The indicators are of three types: a) purely descriptive with no attempt to define optimal values, e.g. number of items prescribed per patient; b) based on unnecessary or potentially harmful prescribing, e.g. duplication; c) assessing the appropriateness of prescribing specific drugs or combinations e.g. digoxin and warfarin/aspirin in atrial fibrillation (AF). Appropriateness was defined on the basis of objective research findings and involved comparing individual patient clinical records to criteria for appropriate prescribing. Prescribing and personal data were collected for medical inpatients aged 65 years or over in 19 hospitals in England and Wales. A total of 1686 patients were included, median age 81 years, 41% were male. RESULTS: Patients were prescribed 11475 items, mean 4.6 regular items per patient. Completion of drug allergy/sensitivity statements varied from 3 to 93% between units. Use of generic name and specification of a maximum frequency of administration for "as required' medicines were more consistent, ranging from 76-94% and 52-81% respectively. Little duplication of therapy was seen. Benzodiazepines were prescribed for 22% patients, but were appropriate in only approximately one third of these. Of the 2% patients prescribed an angiotensin converting enzyme inhibitor with a potassium-sparing diuretic or potassium supplement, prescription of the combination was appropriate in 84%. Coprescription of steroids with beta 2-adrenoceptor agonists appeared excessive in 67% patients receiving a beta 2-adrenoceptor agonist, as only 51% had documented evidence of steroid responsiveness or another indication for steroids. Stroke prophylaxis in AF was inadequate: 22% patients prescribed digoxin also received warfarin or aspirin 300 mg whereas 64% should have received the coprescription. CONCLUSIONS: These prescribing indicators are sensitive to inappropriate prescribing for elderly medical inpatients and cover a wide range of therapeutic areas. They should enable changes in prescribing quality to be measured objectively. Interhospital variation in casemix resulted in substantial differences in the proportion of patients in whom it would have been appropriate to prescribe specific drugs or combinations and prevented derivation of reference ranges of optimal prescribing for four indicators.

Aged↗
PubMed1997

The use of over-the-counter medication by elderly medical in-patients.

Use of over-the-counter (OTC) medications by elderly patients is often not identified. This survey was performed to study the use of OTCs by medical in-patients aged 65 and over. Data on the use of OTC medications before and during hospital admission were collected by questioning patients and case notes were examined for documentation of their use of OTC medications. OTC medications were used by 44 of 138 (32%) patients interviewed. Patients used a total of 70 OTC medications before admission and six OTC medications were being used during hospital admission. There was no documentation of pre-admission and in-hospital OTC medicine use in the clinical notes and patients had little knowledge of the potential harm some products can cause. As more products become available over the counter, doctors should record their use in patients' notes and patients should be encouraged to seek professional advice before purchasing OTC medicines and to read the product information leaflets.

Aged↗
PubMed1996

Aspartame pharmacokinetics - the effect of ageing.

Aspartame is an intense sweetener which is increasingly used in the UK. It is registered at an acceptable daily intake (ADI) of 40 mg/kg, although there are no previous data relating to the metabolism of aspartame in older people. Twelve young and 12 elderly volunteers each received a single dose of approximately 40 mg/kg of aspartame. Baseline concentrations of phenylalanine (the main metabolite of aspartame) rose after ingestion with a significantly higher maximum concentration (Cmax) (81.3 vs. 63.3 micromol/1, p<0.01) and area under the plasma concentration-time curve extrapolated to infinity AUC 9(0-infinity)(518.7 vs. 353.5 micromol . h/l, p<0.01) in the elderly group. The higher concentrations reflected a significant fall in volume of distribution (V) from 2.03 to 1.59 1/kg (p <0.05) and clearance (CL) from 7.3 to 4.9 ml/min/kg (p <0.005) in the elderly group. The greater effect on CL than on V resulted in a small but non-significant rise in elimination half life (3.5 to 3.9 hours). The sizes of the differences were modest implying that there is no need on pharmacokinetic grounds for a change in the ADI for older people.

Adult↗
PubMed1996

Interprofessional clinical education of medical and pharmacy students.

Pharmacists have become increasingly involved in influencing prescribing. Pharmaceutical education has changed accordingly, with increased teaching in therapeutics, partly on hospitals wards, giving students an insight into diseases and helping communication with clinicians. To extend this idea we have designed joint therapeutics teaching sessions with pharmacy and medical students. The scheme involves final year pharmacy students who have completed a course in clinical pharmacy and medical students who have completed their second MB. Interdisciplinary pairs of students are assigned a patient with common medical and therapeutic problems, such as arthritis, diabetes and cardiac failure; patients on multiple drug treatments are preferred. They jointly obtain a history: the medical student performs basic clerking, while the pharmacy student obtains the medication history. The medical student subsequently presents a brief medical history, with a summary of the patient's current problems. For each problem, the pharmacy student presents the current therapy, its rationale and how it is to be monitored. Experience with 73 students over 3 years has shown that almost all found sessions with students from another discipline useful. Few felt that members of the pairs contributed unequally. The main problem appeared to be insufficient time (although 2 1/2 h were allowed). Most students favoured more such sessions. Little difference in ability appeared between the two disciplines; there was considerable co-operation and little nascent 'professional rivalry'. The medical students were more comfortable interviewing patients, and the pharmacy students more confident analysing drug therapy. It is concluded that such interdisciplinary sessions are a successful method of clinical teaching and should be encouraged.

Drug Therapy↗
PubMed1996

Diagnosis and management of the dry mouth: Part 1.

Dry mouth is a relatively common problem, often neglected by patients and dentists alike. This article reviews the symptoms, causes and treatment of xerostomia and provides guidelines for recognizing the condition at an early stage.

Adult↗
PubMed1995

The p47phox mouse knock-out model of chronic granulomatous disease.

Chronic granulomatous disease (CGD) is caused by a congenital defect in phagocyte reduced nicotinamide dinucleotide phosphate (NADPH) oxidase production of superoxide and related species. It is characterized by recurrent life-threatening bacterial and fungal infections and tissue granuloma formation. We have created a mouse model of CGD by targeted disruption of p47phox, one of the genes in which mutations cause human CGD. Identical to the case in human CGD, leukocytes from p47phox-/- mice produced no superoxide and killed staphylococci ineffectively. p47phox-/- mice developed lethal infections and granulomatous inflammation similar to those encountered in human CGD patients. This model mirrors human CGD and confirms a critical role for the phagocyte NADPH oxidase in mammalian host defense.

Abscess↗
PubMed1995

Twenty-four-hour ambulatory blood pressure monitoring in healthy elderly people: reference values.

One hundred and two healthy elderly volunteers (aged 65-83 years) underwent 24-hour ambulatory blood pressure monitoring. Mean day- and night-time pressures were higher than reported for younger subjects. Removing outlying BP measurements from individual 24-hour recordings only minimally affected mean figures of the group but in some individuals mean day diastolic BP may be up to 5 mmHg lower on editing. Using unedited data, mean day and night pressures were 134/81 mmHg and 119/67 mmHg respectively (corresponding 95th centiles 160/96 mmHg and 146/84 mmHg) and systolic and diastolic BP loads were 36% and 21%. These values may be used as temporary reference values for elderly subjects pending the results of longitudinal studies. Studies quoting ABPM data should specify whether data editing has been employed and, if so, the editing thresholds should be stated.

Aged↗
PubMed1995

The bioavailability and disposition of 1-(beta-D-arabinofuranosyl)-5-(1-propynyl)uracil (882C87), a potent, new anti-varicella zoster virus agent.

1. The bioavailability and disposition of 882C87, an anti-varicella zoster virus (VZV) agent, have been investigated in healthy young and elderly volunteers. 2. The mean bioavailability of a 200 mg tablet was 21.1% in the young (range 13.3-33.0%, n = 10) and 24.6% in the elderly (range 14.4-38.4%, n = 8), which is sufficient to achieve plasma concentrations well above the IC50 for anti-VZV activity. 3. Plasma concentrations of 882C87 after 50 mg i.v. were higher in the elderly than in the young, associated with a significantly longer half-life (13.7 vs 11.8 h) and decreased renal clearance (0.11 vs 0.14 ml min-1 kg-1) and total clearance (0.15 vs 0.17 ml min-1 kg-1). 4. After intravenous administration, the main route of elimination of 882C87 was renal with 81.6% recovered unchanged in urine in the young and 71.2% in the elderly. The pyrimidine base, 5-propynyluracil (5-PU) was unquantifiable in plasma and only present in trace amounts in urine. 5. After oral administration to four healthy volunteers, only 17% of a dose of [14C]-882C87 was recovered unchanged in urine and 58% as 5-PU, with total recovery in urine accounting for 86% of the dose. There was a lag of 4-12 h before the appearance of 5-PU in plasma, peak concentrations were one-third to a half those of 882C87. The data suggest that 5-PU is formed from unabsorbed 882C87 in the gut lumen and then absorbed and excreted in urine. 6. 882C87 is a potential once daily treatment for shingles.

Administration, Oral↗
PubMed1995

Hawksley random zero sphygmomanometer versus the standard sphygmomanometer: an investigation of mechanisms.

There has been recent controversy over the accuracy of the Hawksley random zero sphygmomanometer (RZS). In most instances, there has been a bias towards lower recordings with the RZS. In an attempt to identify the mechanism, we designed a study to test the hypothesis that biased error is due to: (1) the magnitude of the random zero; and (2) the magnitude of the pressure being recorded. A RZS (60 mm Hg zero UK version) was connected via a Y-tube to a standard mercury sphygmomanometer (SMS). The circumference of the cam responsible for the variable reservoir size in the RZS was marked into quarters. Within each 10 mm Hg band from 300 to 60 mm Hg, 12 paired readings were taken randomly: three within each of the four quarters of the cam circumference. The mean SMS value was 148.8 vs. 148.2 mm Hg for the RZS. Although of minimal biological significance this difference was highly significant (t = 6.2; p < 0.0001). Our findings fail to confirm the difference between RZS and SMS previously reported and we did not find any evidence of a relation in the difference between SMS and RZS and either the random zero value or the height of the blood pressure. Our findings suggest that if the RZS does under record BP versus the SMS it may relate to a patient-machine interaction not detectable in our system.

Blood Pressure Determination↗
PubMed1995

Investigation of ambulatory blood pressure monitoring data editing criteria.

Ambulatory blood pressure monitoring (ABPM) allows multiple measurements of BP over a 24h period but often produces a proportion of measurements which are distant from the mean and unlikely to be genuine. The software which accompanies the SpaceLabs 90207 monitor requires criteria to be set which excludes outliers (autoediting) but there is no published data evaluating at what levels these autoediting criteria should be set. This study set out to ascertain whether outlying BP measurements represent true blood pressures or machine error, the determinants of machine error and appropriate autoedit criteria. Twenty subjects, both normotensive and hypertensive, were studied by ABPM with a blinded observer recording BP using a standard mercury sphygmomanometer (SMS) connected via a T-tube during three activity phases: sitting with cuffed arm still, walking but keeping arm still during measurement and sitting but gently moving the arm during measurement. The results show that a high ABPM/SMS discrepancy is associated with arm movement. After studying different autoediting criteria which aimed to eliminate the maximum number of conflicting readings while excluding the minimum number of unconflicting readings, an autoediting threshold of between 1.75 and 2 s.d.s from the mean based separately on sleep and awake measurements is suggested.

Aged↗
PubMed1994

The pharmacokinetics and pharmacodynamics of medifoxamine after oral administration in healthy elderly volunteers.

The pharmacokinetics and psychomotor effects of medifoxamine, a 5 HT reuptake inhibitory antidepressant, were studied in healthy elderly volunteers after single and multiple dosing. The elimination half life (t1/2z) after single doses of 300 mg was 2.8 h--almost identical to that found in young volunteers. After seven days of dosing at 100 mg three times daily the mean corrected AUC after 300 mg significantly increased from 1.04 to 1.34 mg.h.l-1 and t1/2z increased to 4.0 h (NS). There were no significant changes in critical flicker fusion frequency, symbol digit substitution, continuous attention or choice reaction times.

Administration, Oral↗
PubMed1994

Psychomotor performance and antihypertensive treatment.

1. The aim of treatment of hypertension is prevention of cardiovascular complications without adverse drug reactions. Psychomotor performance can be measured objectively yet there remains uncertainty concerning the psychomotor effects of antihypertensive drugs during chronic treatment. This uncertainty is partly due to the confounding adverse effects of cerebrovascular disease and hypertension itself. There are as yet insufficient good quality data on psychomotor effects with which to differentiate between the commonly used agents. However, in general, the beneficial effect of lowering blood pressure tends to more than offset any adverse effects of the agent used.

Angiotensin-Converting Enzyme Inhibitors↗