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M H Davidson

Publications and source records attributed to M H Davidson.

66 records · Page 4Linked to original sources
PubMed1994

Fluvastatin administration at bedtime versus with the evening meal: a multicenter comparison of bioavailability, safety, and efficacy.

Fluvastatin is a totally synthetic 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor that is effective in reducing cholesterol when given in a single evening dose. Absorption and rate of bioavailability may be affected when administered with food, but the effect of mealtime dosing on efficacy and safety has not been evaluated. This multicenter, double-blind, placebo-controlled crossover study was performed in 44 patients with primary hypercholesterolemia. Patients received 20 mg of fluvastatin with the evening meal and placebo at bedtime for 6 weeks, followed by 12 weeks of placebo at mealtime and fluvastatin at bedtime (group 1). Group 2 received the opposite treatment schedule, and group 3 received placebo at mealtime and at bedtime for 12 weeks before receiving 20 mg of fluvastatin at bedtime instead of placebo for the final 6 weeks. Fluvastatin with the evening meal resulted in a marginally lower peak serum concentration (p < 0.1) and a significantly delayed time to peak concentration compared with bedtime dosing, but there were no statistically significant differences in the extent of bioavailability. At the end of the first 6 weeks of treatment, similar reductions in low-density lipoprotein (LDL) cholesterol were obtained whether fluvastatin was given at mealtime (-21.8%; p < 0.001) or at bedtime (-23.9%; p < 0.001). After crossover of groups 1 and 2, the results remained constant. With fluvastatin, there were comparable reductions in total cholesterol (p < 0.001) and in LDL:high-density lipoprotein (HDL) ratio (p < 0.001) irrespective of the time of dosing. In conclusion, fluvastatin had a similar tolerability, safety, and efficacy, whether given with the evening meal or at bedtime. There were no serious adverse events nor changes in physical examination findings or laboratory values attributable to treatment.

Adult↗
PubMed1994

Fluvastatin Long-Term Extension Trial (FLUENT): summary of efficacy and safety.

The Fluvastatin Long-Term Extension Trial (FLUENT) evaluated the safety and efficacy of fluvastatin over a period of 48 weeks. All 918 enrolled patients had severe primary hypercholesterolemia (mean baseline low-density lipoprotein [LDL] cholesterol, 227 mg/dL) and had completed one of three previous short-term studies of fluvastatin. This open-label extension study used a starting dose of 20 mg of fluvastatin at bedtime. The dose was titrated to 40 mg to achieve LDL levels of < 3.36 mmol/L (130 mg/dL). If necessary, cholestyramine was added to the fluvastatin treatment to achieve this level. After 48 weeks of treatment, the mean percent change from baseline was statistically significant for LDL (-30.7%; p < 0.001), total (-21.9%; p < 0.001), and HDL (+3.5%; p < 0.001) cholesterol. Of the 836 patients who completed the study, only four (0.5%) withdrew because of drug-related adverse events, which were mainly gastrointestinal. There was one purported case of myopathy in a patient who had a recent history of strenuous physical activity. Newly occurring or worsening lens abnormalities were generally mild and did not require discontinuation of treatment. In conclusion, these results indicate that fluvastatin is safe, effective, and well tolerated in the long-term treatment of primary hypercholesterolemia.

Adult↗
PubMed1993

Antioxidants and lipid metabolism. Implications for the present and direction for the future.

Numerous angiographic trials have demonstrated that the atherosclerotic process can be modified through reductions in levels of low-density lipoprotein (LDL) cholesterol. Recent research has focused on other potential modalities by which atheroroma development might be inhibited. These newer strategies include reduction of the oxidative potential of LDL particles through modification of dietary fat intake; prevention of LDL oxidation through the use of antioxidants; and inhibition of monocyte and macrophage function by omega-3 fatty acids and leukotriene-1 antagonists. Inhibition of acyl-coenzyme A:cholesterol acyltransferase (ACAT) may block intestinal cholesterol absorption and reduce synthesis of very-low-density lipoprotein (VLDL), while simultaneously enriching high-density lipoprotein (HDL) cholesterol. Modification of cholesterol ester transfer protein may be associated with improved reverse cholesterol transport or enlarged HDL particles. In the future, a wide variety of therapeutic modalities may be available for use alone or in combination to reverse atherosclerosis or prevent its progression.

Animals↗
PubMed1992

Maintenance of lower proportions of (n - 6) eicosanoid precursors in phospholipids of human plasma in response to added dietary (n - 3) fatty acids.

Competition between the (n - 3) and (n - 6) types of highly unsaturated fatty acids can diminish the abundance of (n - 6) eicosanoid precursors in a tissue, which in turn can diminish the intensity of tissue responses that are mediated by (n - 6) eicosanoids. The mixture of 20- and 22-carbon highly unsaturated fatty acids maintained in the phospholipids of human plasma is related to the dietary intake of 18:2 (n - 6) and 18:3 (n - 3) by empirical hyperbolic equations in a manner very similar to the relationship reported for laboratory rats (Lands, W.E.M., Morris, A. and Libelt, B. (1990) Lipids 25, 505-516). Analytical results from volunteers ingesting self-selected diets showed an inter-individual variance for the proportion of (n - 6) eicosanoid precursors in the fatty acids of plasma phospholipids of about 5%, but the variance among multiple samples taken from the same individual throughout the day was less (about 3%), closer to the experimental variance of the analytical procedure (about 1%). The reproducibility of the results makes it likely that analysis of fatty-acid composition of plasma lipids from individuals will prove useful in estimating the diet-related tendency for severe thrombotic, arthritic or other disorders that are mediated by (n - 6) eicosanoids. Additional constants and terms were included in the equations to account for the effects of 20- and 22-carbon highly unsaturated (n - 3) fatty acids in the diet. A lower constant for the 20- and 22-carbon (n - 3) fatty acids compared to that for the 18-carbon (n - 3) fatty acid in decreasing the ability of dietary 18:2 (n - 6) to maintain 20:4 (n - 6) in tissue lipids confirmed the greater competitive effectiveness of the more highly unsaturated n - 3 fatty acids in the elongation/desaturation process. Also, a lower constant for direct incorporation of 20-carbon fatty acids of the n - 6 vs. the n - 3 type indicated a greater competitive effectiveness of 20:4 (n - 6) relative to 20:5 (n - 3) in reesterification after release from tissue lipids. The equations may be used in reverse to estimate the dietary intakes of the (n - 3) and (n - 6) fatty acids by using the composition of the fatty acids that had been maintained in plasma lipids.

Aged↗
PubMed1991

The hypocholesterolemic effects of beta-glucan in oatmeal and oat bran. A dose-controlled study.

Oat cereals rich in the water-soluble fiber beta-glucan have been studied as a dietary therapy for hypercholesterolemia. To determine the hypocholesterolemic response of beta-glucan in the diet, 156 adults with low-density lipoprotein cholesterol (LDL-C) levels above 4.14 mmol/L (160 mg/dL) or between 3.37 and 4.14 mmol/L (130 and 160 mg/dL) with multiple risk factors were randomized to one of seven groups. Six groups received either oatmeal or oat bran at doses (dry weight) of 28 g (1 oz), 56 g (2 oz), and 84 g (3 oz). A seventh group received 28 g of farina (beta-glucan control). At week 6 of treatment, significant differences were found for both total cholesterol and LDL-C levels among the farina control and the treatment groups who were receiving 84 g of oatmeal, 56 g of oat bran, and 84 g of oat bran, with decreases in LDL-C levels of 10.1%, 15.9%, and 11.5%, respectively. Fifty-six grams of oat bran resulted in significantly greater reductions in LDL-C levels than 56 g of oatmeal. Nutrient analysis shows no difference in dietary fat content between these treatment groups; therefore, the higher beta-glucan content of oat bran most likely explains the significantly greater LDL-C reductions. A dose-dependent reduction in LDL-C levels with oat cereals supports the independent hypocholesterolemic effects of beta-glucan.

Adult↗
PubMed1991

Marine oil capsule therapy for the treatment of hyperlipidemia.

Because marine oil capsules may vary widely in their content of omega-3 fatty acids, saturated fat, and cholesterol composition and, therefore, their biologic potency, we compared the lipid-lowering effects of three representative preparations in patients with different forms of hyperlipidemia. The ester and triglyceride forms of marine oil both effectively lowered triglyceride, but the response of low-density lipoprotein cholesterol was variable; it declined modestly in patients with hypercholesterolemia and was either unchanged or increased in those with hypertriglyceridemia. The saturated fat and cholesterol content of the marine oil preparation appeared to influence the low-density lipoprotein cholesterol response. Therefore, marine oil capsules are useful for lowering levels of very-low-density lipoprotein cholesterol, but the large dose required to achieve and sustain this effect (4.5 g of omega-3 fatty acids, or nine to 18 capsules daily) may limit long-term compliance.

Docosahexaenoic Acids↗
PubMed1989

Effects of dietary supplementation with marine lipid concentrate on the plasma lipoprotein composition of hypercholesterolemic patients.

Although the triglyceride-lowering actions of n-3 fatty acids of marine lipids are now well-recognized, their effects on plasma lipoproteins have not been studied systematically in patients with hypercholesterolemia. To address this question, we supplemented the Phase 1 American Heart Association diets of 14 hypercholesterolemic ambulatory outpatients with a commercially available preparation of marine lipid concentrate (SuperEPA) containing 7.5 g n-3 fatty acids per day and studied their plasma lipids and lipoproteins before and after 30 days of treatment. Both plasma triglyceride and cholesterol levels fell uniformly in all patients while the mean VLDL- and LDL-cholesterol decreased by 58% (P less than 0.005) and 13% (P less than 0.025) respectively. The decrease in whole plasma cholesterol was significantly correlated with the fall in LDL-cholesterol (r = 0.85, P less than 0.01), and not VLDL-cholesterol (r = 0.39, NS). Among the other potentially beneficial actions observed was an increase in HDL2 in all patients (mean increment 41%, P less than 0.005), and an increase in the HDL2/HDL3 ratio (+46%, P less than 0.001) and decreases in the LDL/HDL ratio (-14%, P less than 0.005) and in the unesterified cholesterol/lecithin ratio (-17%; P less than 0.001) in plasma. The increase in the unesterified cholesterol/esterified cholesterol ratio in VLDL and HDL3 suggested that marine lipid therapy resulted in a reduction in the size of lipoprotein particles in these fractions. Since these changes may reduce cardiovascular risk, these findings suggest that marine lipids may prove useful in the treatment of certain patients with hypercholesterolemia.

Adult↗
PubMed1986

Mitral valve prolapse: recent advances in diagnosis and therapy.

MVP is a common condition with rare life-threatening implications. Recent follow-up studies over several years in children, and young and middle-aged adults failed to suggest increase in prolapse in most of the subjects. Older individuals with MVP appear to have increased complications, primarily due to mitral regurgitation. Echocardiography supports the diagnosis of MVP made by auscultation in over 90% of individuals, with excellent reproducibility. MVP is more common in young women than young men. The prevalence of prolapse decreases with age in women; it is relatively constant in men. Although complications are rare, MVP is the most common underlying disorder in rupture of the chordae tendineae. These spontaneous ruptures are usually unassociated with infective endocarditis. Familial studies indicate that isolated MVP is an autosomal dominant condition with variable expression. It is recommended that first-degree relatives of patients with isolated prolapse be examined. Infective endocarditis is uncommon, but it is recommended that antibiotic prophylaxis be implemented in patients with prolapse and evidence for mitral regurgitation. Prolapse is frequently associated with autonomic imbalance, primarily an increased catecholamine sensitivity. The use of beta blockers may reverse symptoms secondary to this abnormality. Sudden death is exceedingly rare despite marked arrhythmias in many patients. On the basis of retrospective studies, sudden death is associated with floppy valves, marked mitral regurgitation, and arrhythmias. There is no evidence that any class of antiarrhythmic agents can prevent the rare sudden deaths in these patients.

Adult↗
PubMed1975

A short-term intensive training program for pediatric nurse practitioners.

A pediatric nurse practitioner course has been described in which 30 nurse trainees spent six seeks in an intensive training program followed by six months of preceptorship with a pediatrician in their own agency. This short but intensive program had advantages of permitting the PNP student to retain her health care agency position during the intensive part of the program and of assuring her a position as a PNP once the course was completed. Evaluation of the students by written and practical examinations indicated that they had made significant gains in their knowledge and understanding of pediatrics and in their ability to evaluate and refer patients and to provide well-child care and maternal counseling.

California↗