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Biomedical subjects

M H Davidson

Publications and source records attributed to M H Davidson.

At least 19 recordsLinked to original sources
PubMed2004

Efficacy and safety of ezetimibe coadministered with statins: randomised, placebo-controlled, blinded experience in 2382 patients with primary hypercholesterolemia.

We assessed pooled safety and lipid-regulating efficacy data from four similarly designed trials of ezetimibe coadministered with statins in 2382 patients with primary hypercholesterolemia. Patients were randomised to one of the following double-blind treatments for 12 weeks: placebo; ezetimibe 10 mg; statin; or statin + ezetimibe. Statin doses tested were 10, 20, 40 mg/day (atorvastatin, simvastatin, pravastatin or lovastatin) or 80 mg/day (atorvastatin, simvastatin). Treatment with ezetimibe + statin led to significantly greater reductions in low-density lipoprotein cholesterol (LDL-C), total cholesterol, triglycerides, non-high-density lipoprotein cholesterol (non-HDL-C), apolipoprotein B and increases in HDL-C, compared to statin alone. At each statin dose, treatment with ezetimibe + statin led to a greater LDL-C reduction compared to the next highest statin monotherapy dose. Ezetimibe + statin had a safety profile similar to statin monotherapy. Coadministration of ezetimibe + statin offers a well-tolerated, highly efficacious new treatment strategy for patients with hypercholesterolemia.

Adolescent↗
PubMed2001

Efficacy and safety of combination simvastatin and colesevelam in patients with primary hypercholesterolemia.

PURPOSE: To examine the efficacy and safety of colesevelam hydrochloride, a novel, nonsystemic, lipid-lowering agent, when coadministered with starting doses of simvastatin in a multicenter, randomized, double-blind, placebo-controlled trial. PATIENTS AND METHODS: Subjects with hypercholesterolemia (plasma low density lipoprotein [LDL] cholesterol level > 160 mg/dL and triglyceride level < or = 300 mg/dL) were randomly assigned to receive daily doses of placebo (n = 33), colesevelam 3.8 g (recommended dose, n = 37), simvastatin 10 mg (n = 35), colesevelam 3.8 g with simvastatin 10 mg (n = 34), colesevelam 2.3 g (low dose, n = 36), simvastatin 20 mg (n = 39), or colesevelam 2.3 g with simvastatin 20 mg (n = 37), for 6 weeks. RESULTS: Mean LDL cholesterol levels decreased relative to baseline in the placebo group (P < 0.05) and in all active treatment groups (P < 0.0001). For groups treated with combination therapy, the mean reduction in LDL cholesterol level was 42% (-80 mg/dL; P < 0.0001 compared with baseline), which exceeded the reductions for simvastatin 10 mg (-26%, -48 mg/dL) or 20 mg (-34%, -61 mg/dL) alone, or for colesevelam 2.3 g (-8%, -17 mg/dL) or 3.8 g (-16%, -31 mg/dL) alone (P < 0.001). The effects of combination therapy on serum HDL cholesterol and triglyceride levels were similar to those for simvastatin alone. Side effects were similar among treatment groups, and there were no clinically important changes in laboratory parameters. CONCLUSION: Coadministration of colesevelam and simvastatin was effective and well tolerated, providing additive reductions in LDL cholesterol levels compared with either agent alone.

Adult↗
PubMed2001

Low-dose combination therapy with colesevelam hydrochloride and lovastatin effectively decreases low-density lipoprotein cholesterol in patients with primary hypercholesterolemia.

BACKGROUND: Colesevelam hydrochloride is a novel, lipid-lowering agent that binds bile acids with high affinity. A multicenter, randomized, double-blind, placebo-controlled, parallel-design study was conducted to assess the efficacy and tolerability of combination low-dose colesevelam and lovastatin treatment in patients with primary hypercholesterolemia. HYPOTHESIS: Combination therapy with low doses of colesevelam and lovastatin decreases low density (LDL) cholesterol with minimal adverse events. METHODS: Following a 4- to 6-week dietary lead in, 135 patients were randomized into five groups for a 4-week treatment period: placebo, colesevelam 2.3 g at dinner, lovastatin 10 mg at dinner, the combination of colesevelam and lovastatin given at dinner (dosed together), and combination treatment with colesevelam given at dinner and lovastatin administered at bedtime (dosed apart). RESULTS: Combination colesevelam and lovastatin treatment decreased LDL cholesterol by 34% (60 mg/dl, p < 0.0001) and 32% (53 mg/dl, p < 0.0001) when colesevelam and lovastatin were dosed together or dosed apart, respectively. Both combination therapies were superior to either agent alone (p < 0.05). Decreases in LDL cholesterol exceeded the combined decreases observed for colesevelam alone (13 mg/dl, 7%) and lovastatin alone (39 mg/dl, 22%). Both combination treatments reduced total cholesterol by 21% (p < 0.0001) and apolipoprotein B by 24% (p < 0.0001). Neither combination treatment significantly altered high-density lipoprotein cholesterol or triglycerides. Adverse side effects were not significantly different among randomized groups. CONCLUSIONS: Combination colesevelam and lovastatin was efficacious and well tolerated, resulting in additive decreases in LDL cholesterol levels whether or not both agents were administered simultaneously.

Allylamine↗
PubMed2001

Statin trials in progress: unanswered questions.

Five years ago, many critics questioned the value of lipid-lowering therapy. Today, the clinical benefits of statins are well documented, but the challenge remains to fully implement these benefits across the wide spectrum of the at-risk population, and continue to advance our understanding regarding the potential for the benefits of statins across an even broader range of select patient populations.

Atorvastatin↗
PubMed2001

Efficacy and short-term safety of a new ACAT inhibitor, avasimibe, on lipids, lipoproteins, and apolipoproteins, in patients with combined hyperlipidemia.

Although acyl-CoA:cholesterol acyltransferase (ACAT) inhibitors have been shown to reduce lipid levels in several animal models, the safety and lipid modifying activity of any single agent in this class has not been demonstrated in humans. The safety and efficacy of avasimibe (CI-1011), a new, unique, wholly synthetic ACAT inhibitor, was evaluated in the treatment of 130 men and women with combined hyperlipidemia and hypoalphalipoproteinemia (low levels of high-density lipoprotein cholesterol [HDL-C]). Following an 8-week placebo and dietary-controlled baseline period, patients were randomly assigned to double-blind treatment with placebo, 50, 125, 250, or 500 mg avasimibe administered as capsules once daily for 8 weeks. At all evaluated doses, avasimibe treatment resulted in prompt and significant reductions (P<0.05) in plasma levels of total triglycerides (TG) and very low-density lipoprotein cholesterol (VLDL-C) with mean reductions of up to 23% and 30% respectively, apparently independent of dose. No statistically significant changes in total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), HDL-C or apolipoprotein (apo) B were detected. ApoAI levels were also unchanged on all doses of avasimibe apart from the 500 mg dosage, which was associated with a significant decrease in plasma apoAI. The relevance of this latter finding in only one dosage group is not known. All doses of avasimibe were well tolerated with no resulting significant abnormalities of biochemical, hematological, or clinical parameters.

Acetamides↗
PubMed2001

Safety and tolerability of esterified phytosterols administered in reduced-fat spread and salad dressing to healthy adult men and women.

OBJECTIVE/DESIGN: The safety and tolerability of three levels of plant sterol-esters administered in reduced-fat spread and salad dressing vs. control products were evaluated in this randomized, double-blind, four-arm parallel study. METHODS: Eighty-four free-living men and women consumed reduced-fat spread and salad dressing providing 0.0 g/day (n = 21), 3.0 g/day (n = 21), 6.0 g/day (n = 19) or 9.0 g/day (n = 23) of phytosterols as esters for an eight-week treatment period. RESULTS: Side effects did not differ among the groups during the study, and there were no study product-related serious adverse events. There were no changes in clinical laboratory values in response to phytosterol intake. Blood concentrations of all fat-soluble vitamins remained within normal reference ranges, and there were no differences in serum vitamin responses among the four groups. Alpha- and trans-beta-carotene levels were reduced in the 9.0 g/day group vs. control (p < 0.05), but all carotenoid values remained within normal ranges throughout the study. All groups receiving phytosterols had significant increases in serum campesterol vs. control (p < 0.001), but beta-sitosterol responses did not differ from control. Total, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol responses did not differ significantly among the groups. The total:HDL cholesterol response in the 9.0 g/day group was significantly different from the control group response (-9.6% vs. 2.6%, p < 0.05). A median increase of 7.8% in serum triglycerides was observed in the control group, which differed significantly from the response in the 3.0 g/day arm (-13.3%, p < 0.05). DISCUSSION: The results of this study indicate that phytosterol esters are well tolerated and show no evidence of adverse effects at a daily intake of up to 9.0 g of phytosterols for eight weeks.

Adolescent↗
PubMed2001

Lipid responses to plant-sterol-enriched reduced-fat spreads incorporated into a National Cholesterol Education Program Step I diet.

BACKGROUND: Plant sterol esters reduce cholesterol absorption and lower circulating blood cholesterol concentrations when incorporated into the habitual diet. OBJECTIVE: This randomized, double-blind, 3-group parallel, controlled study evaluated the influence of esterified plant sterols on serum lipid concentrations in adults with mild-to-moderate primary hypercholesterolemia. DESIGN: Subjects incorporated a conventional 50%-fat spread into a National Cholesterol Education Program Step I diet for a 4-wk lead-in period, followed by a 5-wk intervention period of the diet plus either a control reduced-fat spread (40% fat; n = 92) or a reduced-fat spread enriched with plant sterol esters to achieve intakes of 1.1 g/d (n = 92; low-sterol group) or 2.2 g/d (n = 40; high-sterol group). RESULTS: Subjects in the low- and high-sterol groups who consumed > or = 80% of the scheduled servings (per-protocol analyses) had total cholesterol values that were 5.2% and 6.6% lower, LDL-cholesterol values that were 7.6% and 8.1% lower, apolipoprotein B values that were 6.2% and 8.4% lower, and ratios of total to HDL cholesterol that were 5.9% and 8.1% lower, respectively, than values for the control group (P < 0.001 for all). Additionally, triacylglycerol concentrations decreased by 10.4% in the high-sterol group. Serum concentrations of fat-soluble vitamins and carotenoids were generally within reference ranges at baseline and postintervention. Serum plant sterol concentrations increased from baseline (0.48% of total sterol by wt) to 0.64% and 0.71% by wt for the low- and high-sterol groups, respectively (P < 0.05 compared with control). CONCLUSION: A reduced-fat spread containing plant sterol esters incorporated into a low-fat diet is a beneficial adjunct in the dietary management of hypercholesterolemia.

Adult↗
PubMed2001

Reduction of LDL cholesterol in patients with primary hypercholesterolemia by SCH 48461: results of a multicenter dose-ranging study.

SCH 48461, an inhibitor of gastrointestinal absorption of cholesterol, was evaluated for its effects on lipid parameters in patients with primary hypercholesterolemia in a multicenter, double-blind, randomized, parallel-group study. Following the baseline phase, which consisted of a 2- to 10-week drug washout and dietary stabilization phase and a 4-week placebo lead-in (placebo baseline phase), 190 patients were randomized to an 8-week double-blind active drug (SCH 48461 1, 6.25, 25, 100, 200, or 400 mg) or 40 mg lovastatin once daily each morning or placebo treatment phase. By week 2, patients who received SCH 48461 6.25 to 400 mg or lovastatin demonstrated greater reduction from baseline in directly measured low-density lipoprotein cholesterol (LDL-C) levels than patients in the placebo group (p < or = 0.03). Overall, the percent reductions in LDL-C from baseline increased as the dose of SCH 48461 increased, with 0.6% to 15.5% reductions from the minimum dose of 1 mg to the maximum dose of 400 mg. Lovastatin 40 mg/day reduced LDL-C by 30.7% (p < 0.01). Statistically significant decreases were also seen for total cholesterol and apolipoprotein B (apo B) with doses of 25 mg to 400 mg of SCH 48461 and lovastatin. SCH 48461 was well tolerated. There was a similar incidence of adverse events in each SCH 48461- or lovastatin-treated group compared to placebo. This study demonstrated a clinically and statistically significant cholesterol-lowering effect of SCH 48461 in patients with primary hypercholesterolemia.

Anticholesteremic Agents↗
PubMed2001

Treatment of the elderly with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors: focus on drug interactions.

With the aging of the population, death from coronary heart disease (CHD) and stroke has become more prevalent. Cardiovascular disease (CVD) risk factors, such as hypertension, obesity, and diabetes mellitus increase with age as well. Recent secondary-prevention studies have established the positive effect of statins in decreasing the risk of CHD mortality through the lowering of cholesterol. Statins have an excellent safety record, at least with users under age 65, and provide a cheaper alternative to more costly medical options. The most serious side effect associated with their use is myopathy, which is infrequent. Drug interactions have been found with drugs that compete for the same CYP450 isoenzymes as statins. Several drugs have been shown to significantly inhibit the CYP3A4 pathway; in combination with statins such as lovastatin, simvastatin, atorvastatin, and cerivastatin, they have been shown to elevate serum concentrations of these statins, or may increase the risk of myopathy. Alternatively, other drugs can inhibit the CYP2C9 pathway and may elevate serum concentration of fluvastatin. Due to the number of medications the elderly receive, an understanding of the various metabolic pathways is of vital importance to minimize the potential for drug interactions. The elderly population, while at high risk for CVD, is currently undertreated. Statins can effectively lower low-density lipoprotein cholesterol levels and lessen the risk of CVD for this population.

Aged↗
PubMed2001

Safety profiles for the HMG-CoA reductase inhibitors: treatment and trust.

Hypercholesterolaemia is a chronic condition that often requires life-long treatment, making the safety of lipid-lowering drugs a critical issue. 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors ('statins') are commonly used as the pharmacotherapeutic treatment of choice for patients with hypercholesterolaemia. These agents have consistently demonstrated a positive safety and tolerability profile, and are recommended by the US National Cholesterol Education Program guidelines and by the European Joint Task Force for Prevention of Coronary Heart Disease to be used after, or in addition to, a first-line approach with diet. Several large-scale clinical trials have shown HMG-CoA reductase inhibitors to be efficacious and well tolerated, and to be associated with a low rate of treatment withdrawal due to adverse events. These studies included mortality and morbidity end-points, and comprised both primary- and secondary-prevention trials. Hepatic, renal and muscular systems are rarely affected during HMG-CoA reductase inhibitor therapy and the few drug interactions that can occur with concomitantly administered drugs are well documented. There is no conclusive evidence linking HMG-CoA reductase inhibitors to the development of cancer in humans. In long term studies with various HMG-CoA reductase inhibitors, there was no increase in cancer rates compared with placebo. Thus, it can be concluded that HMG-CoA reductase inhibitors are well tolerated, effective treatments for hypercholesterolaemia.

Anticholesteremic Agents↗
PubMed2001

Effectiveness of colesevelam hydrochloride in decreasing LDL cholesterol in patients with primary hypercholesterolemia: a 24-week randomized controlled trial.

OBJECTIVE: To evaluate the efficacy, tolerability, and safety of colesevelam hydrochloride, a new nonsystemic lipid-lowering agent. PATIENTS AND METHODS: In this double-blind, placebo-controlled trial performed in 1998, 494 patients with primary hypercholesterolemia (low-density lipoprotein [LDL] cholesterol level > or = 130 mg/dL and < or = 220 mg/dL) were randomized to receive placebo or colesevelam (2.3 g/d, 3.0 g/d, 3.8 g/d, or 4.5 g/d) for 24 weeks. Fasting serum lipid profiles were measured to assess efficacy. Adverse events were monitored, and discontinuation rates and compliance rates were analyzed. The primary outcome measure was the mean absolute change of LDL cholesterol from baseline to the end of the 24-week treatment period. RESULTS: Colesevelam lowered mean LDL cholesterol levels 9% to 18% in a dose-dependent manner (P<.001), with a median LDL cholesterol reduction of 20% at 4.5 g/d. The reduction in LDL cholesterol levels was maximal after 2 weeks and sustained throughout the study. Mean total cholesterol levels decreased 4% to 10% (P<.001), while median high-density lipoprotein cholesterol levels increased 3% to 4% (P<.001). Median triglyceride levels increased by 5% to 10% in placebo and colesevelam treatment groups relative to baseline (P<.05), but none of these differences were significantly different from placebo. Mean apolipoprotein B levels decreased 6% to 12% in an apparent dose-dependent manner (P<.001). No significant differences occurred in adverse events or discontinuation rates between groups, and compliance rates were between 88% and 92% for all groups. CONCLUSIONS: Colesevelam was efficacious, decreasing mean LDL cholesterol levels by up to 18%, and well tolerated without serious adverse events.

Adult↗
PubMed2001

A comparison of simvastatin and atorvastatin up to maximal recommended doses in a large multicenter randomized clinical trial.

OBJECTIVE: At higher doses, simvastatin has been shown to produce significantly greater increases in high-density lipoprotein (HDL) cholesterol and apolipoprotein (apo) A-I than atorvastatin. To extend and confirm these findings, a 36-week, randomized, double-blind, dose-titration study was performed in 826 hypercholesterolemic patients to compare the effects of simvastatin and atorvastatin on HDL cholesterol, apo A-I, and clinical and laboratory safety. PRIMARY HYPOTHESIS: Simvastatin, across a range of doses, will be more effective than atorvastatin at raising HDL cholesterol and apo A-I levels. METHODS: A total of 826 hypercholesterolemic patients were enrolled in this double-blind, randomized, parallel, 36-week, dose-escalation study. Patients randomized to simvastatin received 40 mg/day for the first 6 weeks, 80 mg/day for the next 6 weeks, and remained on 80 mg/day for the final 24 weeks. Patients randomized to atorvastatin received 20 mg/day for the first 6 weeks, 40 mg/day for the next 6 weeks, and 80 mg/day for the remaining 24 weeks. RESULTS: During the first 12 weeks of the study, simvastatin increased HDL cholesterol and apo A-I more than the comparative doses of atorvastatin, while producing slightly lower reductions in low-density lipoprotein (LDL) cholesterol and triglycerides. At the maximal dose comparison, simvastatin 80 mg and atorvastatin 80 mg, the HDL cholesterol and apo A-I differences favoring simvastatin were larger than at the lower doses. In addition, at the maximal dose comparison, the incidence of drug-related clinical adverse experiences was approximately two-fold higher with atorvastatin 80 mg than with simvastatin 80 mg (23 versus 12%, p < 0.001), due predominantly to a greater incidence of gastrointestinal symptoms with atorvastatin (10 versus 3%, p < 0.001). The incidence of clinically significant alanine aminotransferase elevations was also higher with atorvastatin 80 mg than with simvastatin 80 mg (3.8 versus 0.5%, p < 0.010), especially in women (6.0 versus 0.6%). CONCLUSIONS: At the doses compared in this study, simvastatin led to greater increases in HDL cholesterol and apo A-I levels than atorvastatin. At the maximum dose comparison, there were fewer drug-related gastrointestinal symptoms and clinically significant aminotransferase elevations with simvastatin.

Adult↗
PubMed2000

Effects of continuous estrogen and estrogen-progestin replacement regimens on cardiovascular risk markers in postmenopausal women.

OBJECTIVE: To evaluate the influence of 2 continuous combined estrogen-progestin replacement products, compared with unopposed estrogen and placebo, on cardiovascular risk markers in postmenopausal women in a randomized, double-blind, placebo-controlled trial. METHODS: Two hundred seventy healthy postmenopausal women were randomly assigned to 1 of 4 treatment groups: placebo, unopposed 17-beta estradiol (1 mg), 1 mg of 17-beta estradiol with 0.25 mg of norethindrone acetate, or 1 mg of 17-beta estradiol with 0.5 mg of norethindrone acetate. The primary outcome variable was change from baseline in low-density lipoprotein cholesterol concentration. Additional outcome variables included changes in other serum lipid levels, hemostatic variables, and indicators of carbohydrate metabolism. RESULTS: The low-density lipoprotein cholesterol level was reduced to a similar degree in all groups receiving active treatment (10%-14% from baseline; P =.001 for 17-beta estradiol with 0.5 mg of norethindrone acetate, P =.004 for 17-beta estradiol with 0.25 mg of norethindrone acetate, and P =. 001 for 1 mg of 17-beta estradiol vs placebo). Compared with unopposed 17-beta estradiol, 17-beta estradiol with 0.5 mg of norethindrone acetate enhanced the reductions in total cholesterol and apolipoprotein B levels (P<.01 vs 17-beta estradiol). 17-beta Estradiol plus norethindrone blunted or reversed the increases in levels of high-density lipoprotein cholesterol, apolipoprotein A-I, and triglycerides produced by 17-beta estradiol alone. Effects of 17-beta estradiol plus norethindrone on hemostatic variables were similar to those of 17-beta estradiol except for factor VII activity, which was significantly reduced with 17-beta estradiol combined with 0.25 mg (P<.01) and 0.5 mg (P<.05) of norethindrone acetate. 17-beta Estradiol plus norethindrone appeared to blunt reductions in C-peptide and insulin levels produced by unopposed 17-beta estradiol but did not elevate these values compared with placebo. CONCLUSIONS: 17-beta Estradiol plus norethindrone produced favorable changes in most cardiovascular risk markers evaluated and has a profile distinct from that of unopposed 17-beta estradiol. The impact of these differences on cardiovascular events warrants investigation. Arch Intern Med. 2000;160:3315-3325.

Aged↗
PubMed2000

Association between elevated plasma fibrinogen and the small, dense low-density lipoprotein phenotype among postmenopausal women.

A predominance of small, dense low-density lipoprotein (LDL) particles (subclass pattern B) has been associated with a 2- to threefold increase in coronary heart disease risk. Recently, it has been reported that LDL subclass pattern B is associated with hyperfibrinogenemia, which is also a coronary heart disease risk factor. The present study examined the relation between hyperfibrinogenemia and LDL subclass pattern in 258 postmenopausal women. A significant univariate correlation was observed between the concentration of cholesterol carried in small, dense LDL particles and plasma fibrinogen concentration (r = 0.17, p = 0.01). The prevalence of LDL subclass pattern B was 41.9% in the highest fibrinogen tertile, compared with 27.9% and 24.4% in the first and second tertiles, respectively (global chi-square 6.8, p = 0.03). The crude odds ratio (OR) for LDL subclass pattern B among women in the highest fibrinogen tertile, compared with the lower tertiles, was 2.03 (95% confidence interval [CI] 1.18 to 3.51, p = 0.01). After adjustment for age and plasma lipids (log(e) triglycerides, LDL cholesterol, and high-density lipoprotein cholesterol), the OR was 2.14 (95% CI 1.17 to 3.96, p = 0.01). Further adjustment for hematocrit, indicators of carbohydrate homeostasis, body mass index, waist circumference, and several variables related to lifestyle did not attenuate this association (OR 2.56, 95% CI 1.27 to 5.27, p = 0.01). These data suggest that hyperfibrinogenemia and LDL subclass pattern B may be 2 components of a common syndrome and suggest that hyperfibrinogenemia may contribute to the increased coronary heart disease risk associated with LDL subclass pattern B.

Aged↗