Biomedical subjects
R C Hamdy
Publications and source records attributed to R C Hamdy.
Nursing homes: reducing the impact of institutionalization.
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A multiple dose pharmacokinetic and tolerance study of once daily 200 mg sustained-release flurbiprofen capsules in young and very elderly patients.
The pharmacokinetic profile of 200 mg sustained-release flurbiprofen capsules was compared in nine elderly (mean age 84.2 years) and 10 young (mean age 38.1 years) patients with arthritis. After a single capsule, a 48 h plasma concentration profile was performed. The patients then took 1 capsule daily for a further 13 days with plasma levels of the drug being measured pre-dose on alternate days. Following ingestion of the last capsule, a further 48 hour plasma concentration profile was performed. These results were compared with each other and with computer predicted data obtained from dosing with 200 mg conventional flurbiprofen (as 100 mg b.d.). In both young and elderly patients, the two 48 h plasma concentration profiles confirmed the sustained-release characteristics of the capsule. There was no evidence of dose-dumping, although, in one elderly patient with a partial gastrectomy, higher plasma concentrations were observed. Inter- and intra-patient variability was acceptable. A steady-state was achieved within the predicted four days in both groups and there was no evidence of accumulation with the daily dosing interval. A mean steady-state level of approximately 6 micrograms/ml was achieved for both populations. Computer predicted data for 200 mg conventional flurbiprofen (as 100 mg b.d.) showed a pre-dose/peak range of 1-12 micrograms/ml. The pre-dose/peak ranges for the young and old patients were 4-10 micrograms/ml and 4-8 micrograms/ml respectively. One young patient developed a hypersensitivity reaction of moderate severity; one young and four elderly patients developed a low haemoglobin concentration during the study. No other changes in haematological or biochemical parameters were seen.
Aluminum toxicity and Alzheimer's disease. Is there a connection?
Similarities between Alzheimer's disease and aluminum toxicity have led to the suggestion that a causal relationship may exist. However, the two disorders differ in many respects. The author reviews the evidence concerning the relationship between aluminum toxicity and Alzheimer's disease and answers the question, is there a connection?
Metabolic bone disease: a review.
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A comparative study of cholecalciferol, dihydrotachysterol and alfacalcidol in the treatment of elderly patients with hypocalcaemia.
Fifty elderly patients with hypocalcaemia were randomly treated for 8 weeks with either oral dihydrotachysterol, parenteral cholecalciferol or oral alfacalcidol. All three treatments were successful in normalizing the serum calcium levels in most patients within 2 weeks. Hypercalcaemia was seen only with alfacalcidol but was rapidly reversed once treatment was discontinued. Hypercalcaemia was not observed with either dihydrotachysterol or cholecalciferol. These therefore, require less frequent biochemical monitoring. A single cholecalciferol injection eliminates the problems of compliance.
The management of osteoporosis.
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Urinary electrolyte excretion after frusemide, amiloride and Frumil: single dose studies.
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Urinary electrolyte excretion after frusemide and Frumil: multiple dose study.
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The short-term effects of reducing elevated blood pressure in elderly patients with propranolol and dyazide.
Propranolol and Dyazide (25 mg hydrochlorothiazide and 50 mg triamterene) were used singly to reduce the elevated blood pressure (systolic ranging from 170 to 271 mmHg and diastolic ranging from 100 to 141 mmHg) of 38 elderly hypertensive patients whose ages ranged from 69 to 91 years. Each compound was administered for a period of four weeks with a wash-out period of four weeks in between. The following parameters were assessed before and after each treatment period: cerebral blood flow (CBF), mental functions, cardiac output (CO), electrocardiogram, glomerular filtration rate (GFR) and serum biochemistry. Both systolic and diastolic blood pressure were significantly reduced following the administration of either compound. No significant change in CBF and CO could be observed after reducing the blood pressure whether Propranolol or Dyazide was used. The GFR was, however, significantly reduced and the plasma creatinine significantly increased following Dyazide but not Propranolol administration. As expected the administration of the latter compound was associated with a significant bradycardia. No significant change could be observed in the other parameters studied.
Urinary electrolyte excretion after frusemide, amiloride and a combination of these drugs: an open, crossover study.
Urinary volume and electrolyte excretion were monitored for 24 hours in 12 elderly, catheterized patients with mild congestive cardiac failure. Five timed collections (0 to 3, 3 to 6, 6 to 9, 9 to 12 and 12 to 24 hours) were made after single doses of 40 mg frusemide, 5 mg amiloride and a combination tablet containing both 40 mg frusemide and 5 mg amiloride. Patients received each therapy according to a Latin Square design, with a 6-day washout phase separating the three study periods. The study periods consisted of a 24-hour control urinary collection, immediately followed by diuretic and a further 24-hour urine collection. Diuretics were not administered immediately prior to the study or during the washout phases. Amiloride, as expected, showed mild diuretic and natriuretic properties, but in the 12 to 24-hour period it induced a greater diuresis (p less than 0.05) than did frusemide or the combination. Frusemide and the combination tablet both produced a rapid and powerful diuresis in the 0 to 3-hour post-dose period and did not differ significantly in urine output at any time point. However, a difference in natriuretic activity was seen between frusemide and the combination, with the latter producing a significantly greater sodium excretion in the 12 to 24-hour period (p less than 0.05). Potassium-retaining activity throughout the 24 hours was marked after amiloride, with potassium excretion being significantly less (p less than 0.05) than either control, frusemide or the combination.(ABSTRACT TRUNCATED AT 250 WORDS)
Osteoporosis: aetiology and management.
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Vitamin A and Paget's disease.
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The pharmacokinetics of benoxaprofen in elderly subjects.
Benoxaprofen plasma profiles were obtained in two groups of elderly female patients. A single dose of benoxaprofen, either 600 mg or 300 mg, was given and blood levels were measured daily to 120 hours. Mean peak plasma levels were reached at five hours following the 600-mg dose and at seven hours after the 300-mg dose. Elimination half-lives calculated from levels during 36-120 hours resulted in means of 111 hours and 86.4 hours for the 600-mg and 300-mg doses respectively. (Normal subjects, 30 to 35 hours.) Because of these extended half-lives, a further study was conducted following a single 600-mg dose to four more patients. Blood vessels were measured up to 504 hours (21 days). This resulted in a means half-life of 147.9 hours calculated from levels during 168-504 hours. Although serum creatinine levels ere not generally above the normal for this age group, calculated creatinine clearances were considerably reduced. It is concluded that the high plasma benoxaprofen levels achieved, combined with the slow clearance rates and long half-lives, indicate that it may be possible to work is needed to determine whether this prolonged half-life is matched by an equally prolonged therapeutic effect.