PubMed Health⌕ Search

Biomedical subjects

T J Kotze

Publications and source records attributed to T J Kotze.

At least 19 recordsLinked to original sources
PubMed1996

An investigation into the prescribing patterns of selective serotonin re-uptake inhibitors in South Africa.

The primary aim of the study was to investigate the prescribing patterns of selective serotonin re-uptake inhibitors (SSRIs) used on a chronic basis in a defined South African patient population, and to calculate the average prescribed daily doses (PDDs) of selected SSRIs. Prescription data for 2117 patients from various medical schemes who were using antidepressant drugs on a chronic basis were analysed retrospectively. More than 70% of all the patients using antidepressants were females. The tricyclic antidepressants (TCAs) and the SSRIs accounted for approximately 75% of all the antidepressants prescribed. The average age of the patients using SSRIs was 48.1 years (SD = 13.4 years). Fluoxetine was the most frequently prescribed SSRI, accounting for 63.3% of all SSRI prescriptions and 21.9% of all antidepressant prescriptions. The average PDDs of citalopram (23.9 mg), fluoxetine (21.7 mg) and paroxetine (21.1 mg) were slightly higher than their defined daily doses (20 mg for all three drugs). The average PDD of fluvoxamine (93.5 mg) was lower than the DDD (150 mg), but was still within an acceptable dose range. It was concluded that fluoxetine was clearly the drug of choice in treating chronic depression in this patient sample, and that the PDDs used in the patient population studied were in agreement with local and internationally acceptable dosage ranges.

Adolescent↗
PubMed1996

The defined daily dose as a measure of drug consumption in South Africa. A preliminary study.

OBJECTIVE: To perform a preliminary investigation into the us e of the defined daily dose (DDD) as a unit to measure drug utilisation in South Africa. The DDD methodology has been applied in many countries in Western Europe and in other parts of the world. However, research using the DDD method is still lacking in South Africa despite the important role that it can play in economic planning and the improvement of prescribing practices. DESIGN: A retrospective drug utilisation study using da ta from a medical aid. Consumption of selected central nervous system drugs in a formulary system was determined. SETTING: Doctors and patients located in an area of Port Elizabeth. PARTICIPANTS: The prescribing behavior of 50 dispensing doctors serving a homogeneous demographic and socioeconomic patient population was analysed. OUTCOME MEASUREMENTS: The DDD/1,000 registered patients/day, the cost per DDD and the relationship between the two units. RESULTS: Values for the DDD/1,000 registered patients/day were on average lower than international values, but similar trends were observed. The cost per DDD for antipsychotic and antidepressant drugs was on average higher than for hypnotic and anxiolytic drugs. There was an inverse relationship between the DDD/1,000 registered patients/day and the cost per DDD. CONCLUSIONS: The DDD methodology is a useful technique to enable drug consumption data to be measured and compared both nationally and internationally. It can be regarded as a valuable tool for the promotion of rational and cost-effective use of medicine in a future health care system for South Africa.

Central Nervous System Depressants↗
PubMed1996

An investigation into the prescribing of analgesics.

OBJECTIVE: To investigate the prescribing of analgesic agents in a defined South African patient population. DESIGN: Retrospective drug utilisation study. SETTING: Prescribing behaviour of a sample of 50 dispensing doctors in Port Elizabeth. Data were obtained from a medical aid which used a formulary system. MAIN OUTCOME MEASURES: Percentage of central nervous system drugs that analgesics comprised; proportion of patients using combination analgesics; cost of analgesics. RESULTS: On average, 83.3% of all central nervous system drugs dispensed were analgesic agents. These agents represented 70.9% of the total cost of central nervous system drugs. A high percentage (82.2%) of the analgesic agents dispensed were combination or polycomponent analgesics. The combination analgesic tablet, consisting of paracetamol, meprobamate, caffeine and codeine phosphate, was the most frequently prescribed central nervous system drug. This product accounted on average for 40.4% of all analgesics dispensed. Nearly half (46.0%) of all the analgesics dispensed by the sample of doctors were available without a prescription. CONCLUSION: The high prescribing rate of combination analgesic prescription was a cause for concern, given the dependence-producing potential of some of the ingredients, e.g. meprobamate. The prescribing and use of analgesics should be carefully monitored by further drug utilisation studies in light of the serious adverse effects, such as analgesic nephropathy, associated with the longterm use of these agents.

Analgesics↗
PubMed1996

A drug utilisation study investigating prescribed daily doses of hypolipidaemic agents.

OBJECTIVES: To estimate average prescribed daily doses (PDDs) for selected hypolipidaemic agents available on the South African market. Comparison of the estimated PDDs with established DDDs (defined daily doses) and international dosage ranges. To investigate the age and gender of the users of the different hypolipidaemic drugs and drug groups. DESIGN: Retrospective drug utilisation study using data from an organisation involved in the pre-certification of chronic medication. SETTING: Doctors and patients in South Africa. Participants. A total of 2,336 patients of various medical aids who were using cholesterol-lowering medication on a chronic basis. OUTCOME MEASURES: The PDDs, for the complete sample and for the age and gender groups. RESULTS: More than 90% of all hyperlipidaemic patients in the study were treated with HMG CoA reductase inhibitors or fibrates. The average PDDs for the three most frequently prescribed lipid-lowering drugs were 414.4 mg for bezafibrate, 12.5 mg for pravastatin and 12.6 mg for simvastatin. The PDDs were on average lower than the established DDDs. Differences were observed in the pattern of lipid-lowering drug prescriptions for women and men. Male users were on average 3.9 years younger than female users. CONCLUSIONS: The PDDs used in the patient population studied were within locally and internationally acceptable dosage ranges, but were generally lower than established DDDs for lipid-lowering drugs. Prescription differences exist between female and male patients and between age groups with regard to chronic medication. Further studies should be conducted to investigate hypolipidaemic drug prescribing in patients who are not on chronic medication.

Adolescent↗
PubMed1995

Vasopressin secretion and memory impairment in alcoholic Korsakoff's syndrome.

The response of arginine vasopressin (AVP) to an intravenous hypertonic saline infusion was investigated in 19 patients with alcoholic Korsakoff's syndrome, 17 non-amnesic alcoholics and 21 non-alcoholic controls. Compared with non-alcoholic controls the Korsakoff patients had elevated basal AVP levels and showed erratic fluctuation of AVP secretion, not related to changes in serum sodium levels. The non-amnesic alcoholics had a similar, but less severe derangement. Neuropsychological tests revealed significant correlations between basal AVP levels and memory performance in the non-amnesic alcoholics, raising the possibility of a common lesion--most likely in the diencephalon--for memory impairment and AVP dysregulation in chronic alcoholics.

Adult↗
PubMed1994

Alkali-soluble and insoluble fluoride in erupted and unerupted human enamel from a high fluoride area with a low fluorosis score.

The amounts of fluoroapatite and 'CaF2-like' fluoride (F) were determined in enamel of unerupted and erupted teeth that had been exposed in vivo to 1.8-2.6 parts/10(6) F in the drinking water and to brushing with F dentifrice at least once a day, and occasionally to a F mouth-rinse (0.022% F). Enamel was sampled by acid-etching and the F levels were measured with an adapted F ion-selective electrode. More F was built into the deeper enamel in the high-F area than in a similar low-F area. Unerupted enamel did not etch significantly (p > 0.05) deeper than erupted enamel. No significant differences (p > 0.05) were found in the F concentrations amongst the following: alkali-washed erupted, unwashed erupted, alkali-washed unerupted and unwashed unerupted at the outer most enamel (approx. 6 microns). However the erupted enamel (alkali-washed or not) showed higher F levels than unerupted enamel (alkali-washed or not) between approx. 6 microns and greater than 100 microns. The increase of F for this high-F area was about 100% in the deeper enamel while for a low-F area it was approx. 78% in the most outer enamel with no increase after a depth of about 20 microns. In contrast to a similar low-F area (water F < 0.10 parts/10(6)), no significant 'CaF2-like' F could be detected in erupted or unerupted enamel for the high-F area.

Dental Enamel↗
PubMed1994

Corticosteroid therapy and bone mass--comparison of rheumatoid arthritis and systemic lupus erythematosus.

This study was designed to evaluate the effects of low-dose corticosteroid (CS) therapy for rheumatoid arthritis (RA) and of high-dose CS therapy for systemic lupus erythematosus (SLE) on metacarpal bone mass in young (premenopausal) subjects. Ninety-eight patients with RA, 63 patients with SLE and 85 healthy controls of comparable age, race, sex and nutritional status were studied. Metacarpal bone mass was measured by radiogrammetry using a digitiser. In the RA patients, mean bone mass of CS-treated subjects (27%) was 52.31 g/cm2, while that of untreated subjects was 56.69 g/cm2 (P < 0.02). In the SLE group, mean bone mass of CS-treated subjects (76%) was 61.47 g/cm2 and that of untreated subjects 62.36 g/cm2 (P > 0.1). Although patients with SLE required larger cumulative doses of CS for longer periods, their bone mass was higher than that of the RA subjects (P < 0.01). None of the patients had femoral neck or vertebral crush fractures. In RA, bone loss was probably a feature of severe disease rather than of CS therapy.

Adrenal Cortex Hormones↗
PubMed1994

Endocrine function in alcoholic Korsakoff's syndrome.

Hypothalamic-pituitary function was studied by means of several dynamic endocrine tests in 19 patients with alcoholic Korsakoff's syndrome, 17 non-amnesic alcoholics and 21 non-alcoholic controls. The responses of thyroid stimulating hormone, prolactin, follicle stimulating hormone, and luteinizing hormone to a combined thyrotropin releasing hormone and gonadoliberin stimulation test did not differ significantly. For the dexamethasone suppression test, the Korsakoff patients had significantly higher basal serum cortisol and 08:00 hr post-dexamethasone cortisol levels than non-alcoholic controls. These findings raise the possibility that chronically elevated cortisol levels may contribute to cognitive impairment in alcoholic Korsakoff's syndrome.

Adult↗
PubMed1993

The influence of consuming fatty fish instead of red meat on plasma levels of vitamins A, C and E.

The effect of fatty fish consumption on the plasma levels of vitamins A, C and E and the intake of these vitamins were studied in 12 males and 16 females with a mean age of 32.4 years. This cross-over study had a 3 week baseline, 6 week experimental and 6 week post-experimental period with a washout period of approximately 3 months in between. Four 7 day dietary records were used to collect dietary information. Blood samples were drawn after an overnight fast at baseline and every third week thereafter. Plasma total cholesterol, high density lipoprotein cholesterol, triacylglycerol, vitamin A, C and E levels were determined. During the experimental periods red meat was consumed by half of the volunteers while fatty fish was consumed by the other half. Diets were crossed-over after the washout period. Plasma levels of vitamins A, C and E remained within normal limits in the experimental periods. The intake of polyunsaturated fatty acids (PUFA) was significantly higher in the experimental fatty fish period than in the experimental red meat period. The dietary ratio of vitamin E: PUFA and the plasma vitamin E level were lower (P < 0.01) in the experimental fatty fish period than in the experimental red meat period but the ratio of plasma vitamin E: total cholesterol plus triacylglycerol did not differ between the experimental periods. In this study none of the experimental groups were at risk in terms of their intake of the antioxidant vitamins.

Adult↗
PubMed1993

Helicobacter pylori prevalence in non-ulcer dyspepsia--ethnic and socio-economic differences.

Helicobacter pylori is an important cause of gastritis and a number of therapeutic trials suggest that it may be important in the genesis of duodenal ulcer recurrence. The reported prevalence of gastric colonisation by the organism varies considerably. The aim of this cross-sectional survey was to determine its prevalence in non-ulcer dyspeptics and to determine whether this is influenced by age, race, sex, socio-economic status, educational level and the number of persons sharing accommodation. One hundred and sixty-nine patients underwent endoscopy; biopsy specimens were taken from the antrum and H. pylori status was determined histologically. Gastric colonisation was found in 106 patients (63%). The prevalence showed a marked ethnic difference: 40% in whites and 71% in coloureds (P < 0.001). The ethnic groups were characterised by significant differences in socio-economic status (P < 10(-6)), educational level (P < 10(-6)), number of persons sharing accommodation (P < 10(-6)) and age (P < 0.001). These same differences were found when comparing the H. pylori-positive and negative groups, but were less marked and could be attributed to the marked differences between ethnic groups. We conclude that H. pylori prevalence differs between the ethnic groups studied. This may be because of varying degrees of exposure risk.

Adult↗
PubMed1992

Endoscopic investigation for gastric cancer in a high-risk group.

Early gastric cancer (EGC) was diagnosed in only a small percentage (less than 1%) of gastric cancer cases seen at Tygerberg Hospital over a 10-year period (1976-1985). This study, aimed at increasing the yield of EGC, was conducted in some high-incidence areas for gastric cancer. Coloured men, who are at high risk for gastric cancer, were identified by their medical practitioners and investigated. A total of 272 coloured males with nonspecific foregut symptoms underwent upper gastro-intestinal endoscopy and multiple biopsy specimens were obtained from all localised mucosal lesions. Twelve gastric cancers were histologically verified, of which 11 were diagnosed in males over 40 years of age. Two EGCs were diagnosed in older males, resulting in a markedly higher proportion of EGC in this subgroup (18.2%) than the proportion of EGC in inpatients at our institution (0.9%). Twenty-two per cent of males over 40 years of age had gastric ulcers compared with 9.2% of younger males. Chronic atrophic gastritis was present in 56.2% of older males but in only 24.6% of younger males. Those over 40 years of age emerged as a subgroup with a high prevalence of gastric cancer and EGC, and concomitant conditions.

Adult↗
PubMed1992

Blood vitamin concentrations during the acute-phase response.

OBJECTIVES: To investigate the effect, if any, of the acute-phase response on blood vitamin concentrations and to test the hypothesis that these concentrations may change during stress. DESIGN: Open study, utilizing a volunteer sample of patients. SETTING: Tertiary care center. PATIENTS: Twenty-six healthy adult volunteers (14 female and 12 male); 25 volunteers underwent uncomplicated orthopedic surgery and one suffered traumatic limb fractures. INTERVENTIONS: None. MAIN OUTCOME MEASUREMENTS: The presence of a systemic acute-phase response was documented by the determination of serum C-reactive protein concentrations. Blood vitamin concentrations were determined from sequentially collected blood samples over a 7-day period, and compared with entry values. RESULTS: The presence of the acute-phase response was documented by significant and transient increases in C-reactive protein values. This response was accompanied by significant and transient decreases in the concentrations of leukocyte vitamin C, and in plasma concentrations of vitamin A, retinol-binding protein, vitamin E, total lipids, pyridoxal-5'-phosphate, and albumin. Blood concentrations of pyridoxal-5'-phosphate, retinol-binding protein, and leukocyte vitamin C decreased to values below the respective normal ranges. These concentrations normalized without any therapeutic interventions. CONCLUSIONS: We demonstrated transient, but significant, decreases in blood vitamin concentrations during the acute-phase response. Recommendations regarding daily supplementation with these vitamins in clinical practice cannot be made on the basis of these results, as the functional importance of these observations is not, at present, clear. However, what is clear is that biochemical vitamin concentrations, determined during the acute-phase response, should be interpreted with care.

Acute-Phase Reaction↗
PubMed1992

Simvastatin in non-insulin-dependent diabetic patients with hypercholesterolaemia.

The objective of this study was to evaluate the lipid-lowering effect of simvastatin in non-insulin-dependent diabetes mellitus (NIDDM) patients with hypercholesterolaemia while possible clinical and biochemical adverse effects were monitored for. Forty-three NIDDM patients with hypercholesterolaemia (total cholesterol > 6.5 mmol/l) used simvastatin after a detailed clinical laboratory evaluation as well as a 4-week wash-out period and a 4-week placebo baseline period. Simvastatin treatment was initiated with a 10 mg dose for 6 weeks; this was increased to 20 mg and 40 mg at 12 and 18 weeks of follow-up respectively if the total cholesterol level had not decreased to below 5.17 mmol/l. Patients were placed on a lipid-lowering diet and continued to take any regular non-lipid-lowering medication throughout the trial; side-effects were monitored at 6-week intervals until patients had taken simvastatin for 24 weeks. The mean total cholesterol level was reduced by 22.2% at the first follow-up visit, and by 24.2%, 23.3%, and 28.5% at the second, third and fourth follow-up visits respectively compared with base-line levels. A dose of 10 mg simvastatin brought about a reduction in total cholesterol similar to those found with higher doses. The mean triglyceride level was reduced by 20.9% with 20 mg simvastatin. The high-density lipoprotein cholesterol level was not altered significantly and neither was the control of diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

A 6-month trial of simvastatin (HMG-CoA reductase inhibitor) in the treatment of hypercholesterolaemia.

The aim of this study was to evaluate the long-term efficacy and tolerability of the 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor simvastatin, over a 24-week period. Patients (108) with primary hypercholesterolaemia were clinically, haematologically and biochemically evaluated and established on a cholesterol-lowering diet. After a wash-out period free from other lipid-lowering drugs and a baseline period on placebo of 1 month each, 10 mg simvastatin was introduced at night. The dose was increased to 20 mg and 40 mg at 6 and 12 weeks' follow-up respectively if the total cholesterol (TC) level was still above 5.17 mmol/l. Follow-up took place every 6 weeks and included lipid, haematological, biochemical and clinical evaluation. A full ophthalmological evaluation was conducted at baseline and at 24 weeks' follow-up. Overall the TC level was reduced below the baseline level by 34.3% at week 18 of follow-up and 32.5% at week 24. Patients with higher initial TC levels showed greater TC lowering in response to simvastatin than did those with lower initial TC levels. A group of 45 patients was followed up for an additional 12 weeks after the end of the trial and maintained TC reductions similar to those at the end of the trial. Fourteen patients experienced adverse effects which were thought to be drug-related. One patient was withdrawn from the trial after developing conjunctivitis that proved to be related to the use of simvastatin.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

The effect of airborne lead on lead levels of blood, incisors and alveolar bone of rats.

Groups of 20 inbred rats were exposed to: (1) "clean air" (0.05 micrograms Pb/m3) for 70 days; (2) 77 micrograms Pb/m3 for 70 days; (3) 249 micrograms Pb/m3 for 28 days; and (4) 1546 micrograms Pb/m3 for 50 days. Half the rats in each group were then killed and the other half kept in "clean air" until the blood lead of groups 1-3 had returned to normal. That half of the incisors which had been completely renewed during the experimental period, as well as the alveolar bone of each rat, were analysed for lead by atomic absorption spectrophotometry. In the rats killed immediately after exposure, the lead levels by atomic absorption alveolar bone showed significant differences (p less than 0.05) among all four groups, except between groups 2 and 3, indicating the importance of the combined effect of airborne lead concentration and length of exposure. For blood, significant differences (p less than 0.05) were found among all groups. For the post-exposure rats, the incisors and blood showed no significant differences (p greater than 0.05) among groups 1, 2, and 3. For alveolar bone, significant differences were not found (p greater than 0.05) between groups 2 and 3. It can be concluded that during lead exposure the alveolar bone transformation was the highest and that of incisor tissue just lower, and that blood lead became supplemented through the process of remobilization from alveolar bone, as reported for other bones.

Aerosols↗