Safety and compliance with once-daily niacin extended-release/lovastatin as initial therapy in the Impact of Medical Subspecialty on Patient Compliance to Treatment (IMPACT) study

Interventions to improve adherence to lipid-lowering medication

BACKGROUND

Lipid-lowering drugs are widely underused, despite strong evidence indicating they improve cardiovascular end points. Poor patient adherence to a medication regimen can affect the success of lipid-lowering treatment.

OBJECTIVES

To assess the effects of interventions aimed at improving adherence to lipid-lowering drugs, focusing on measures of adherence and clinical outcomes.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, PsycINFO and CINAHL up to 3 February 2016, and clinical trials registers (ANZCTR and ClinicalTrials.gov) up to 27 July 2016. We applied no language restrictions.

SELECTION CRITERIA

We evaluated randomised controlled trials of adherence-enhancing interventions for lipid-lowering medication in adults in an ambulatory setting with a variety of measurable outcomes, such as adherence to treatment and changes to serum lipid levels. Two teams of review authors independently selected the studies.

DATA COLLECTION AND ANALYSIS

Three review authors extracted and assessed data, following criteria outlined by the Cochrane Handbook for Systematic Reviews of Interventions. We assessed the quality of the evidence using GRADEPro.

MAIN RESULTS

For this updated review, we added 24 new studies meeting the eligibility criteria to the 11 studies from prior updates. We have therefore included 35 studies, randomising 925,171 participants. Seven studies including 11,204 individuals compared adherence rates of those in an intensification of a patient care intervention (e.g. electronic reminders, pharmacist-led interventions, healthcare professional education of patients) versus usual care over the short term (six months or less), and were pooled in a meta-analysis. Participants in the intervention group had better adherence than those receiving usual care (odds ratio (OR) 1.93, 95% confidence interval (CI) 1.29 to 2.88; 7 studies; 11,204 participants; moderate-quality evidence). A separate analysis also showed improvements in long-term adherence rates (more than six months) using intensification of care (OR 2.87, 95% CI 1.91 to 4.29; 3 studies; 663 participants; high-quality evidence). Analyses of the effect on total cholesterol and LDL-cholesterol levels also showed a positive effect of intensified interventions over both short- and long-term follow-up. Over the short term, total cholesterol decreased by a mean of 17.15 mg/dL (95% CI 1.17 to 33.14; 4 studies; 430 participants; low-quality evidence) and LDL-cholesterol decreased by a mean of 19.51 mg/dL (95% CI 8.51 to 30.51; 3 studies; 333 participants; moderate-quality evidence). Over the long term (more than six months) total cholesterol decreased by a mean of 17.57 mg/dL (95% CI 14.95 to 20.19; 2 studies; 127 participants; high-quality evidence). Included studies did not report usable data for health outcome indications, adverse effects or costs/resource use, so we could not pool these outcomes. We assessed each included study for bias using methods described in the Cochrane Handbook for Systematic Reviews of Interventions. In general, the risk of bias assessment revealed a low risk of selection bias, attrition bias, and reporting bias. There was unclear risk of bias relating to blinding for most studies.

AUTHORS' CONCLUSIONS

The evidence in our review demonstrates that intensification of patient care interventions improves short- and long-term medication adherence, as well as total cholesterol and LDL-cholesterol levels. Healthcare systems which can implement team-based intensification of patient care interventions may be successful in improving patient adherence rates to lipid-lowering medicines.

Niacin inhibits fat accumulation, oxidative stress, and inflammatory cytokine IL-8 in cultured hepatocytes: Impact on non-alcoholic fatty liver disease

OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) is a common disorder characterized by excessive hepatic fat accumulation, production of reactive oxygen species (ROS), inflammation and potentially resulting in non-alcoholic steatohepatitis (NASH), cirrhosis and end-stage liver disease. Recently, we have shown that niacin significantly prevented hepatic steatosis and regressed pre-existing steatosis in high-fat fed rat model of NAFLD. To gain further insight into the cellular mechanisms, this study investigated the effect of niacin on human hepatocyte fat accumulation, ROS production, and inflammatory mediator IL-8 secretion.

MATERIALS AND METHODS

Human hepatoblastoma cell line HepG2 or human primary hepatocytes were first stimulated with palmitic acid followed by treatment with niacin or control for 24 h.

RESULTS

The data indicated that niacin (at 0.25 and 0.5 mmol/L doses) significantly inhibited palmitic acid-induced fat accumulation in human hepatocytes by 45-62%. This effect was associated with inhibition of diacylglycerol acyltransferase 2 (DGAT2) mRNA expression without affecting the mRNA expression of fatty acid synthase (FAS) and carnitine palmitoyltransferase 1 (CPT1). Niacin attenuated hepatocyte ROS production and it also inhibited NADPH oxidase activity. Niacin reduced palmitic acid-induced IL-8 levels.

CONCLUSIONS

These findings suggest that niacin, through inhibiting hepatocyte DGAT2 and NADPH oxidase activity, attenuates hepatic fat accumulation and ROS production respectively. Decreased ROS production, at least in part, may have contributed to the inhibition of pro-inflammatory IL-8 levels. These mechanistic studies may be useful for the clinical development of niacin and niacin-related compounds for the treatment of NAFLD/NASH and its complications.

Safety and efficacy of long-term combination therapy with bezafibrate and ezetimibe in patients with dyslipidemia in the prospective, observational J-COMPATIBLE study

Background

There are numerous reports describing the efficacy of fenofibrate in combination with ezetimibe for treating dyslipidemia. In contrast, a study combining bezafibrate and ezetimibe has not yet been conducted. In this study, we examined the safety, including the risk of gallstone formation, and the efficacy of long-term combination therapy with bezafibrate and ezetimibe for treating dyslipidemia.

Methods

Dyslipidemic patients treated with 400 mg/day bezafibrate in combination with 10 mg/day ezetimibe for the first time were eligible. We selected 157 institutions in Japan and conducted a 12-month prospective observational study, with patients enrolled on the day they started combination therapy. Safety of the combination was examined in terms of the type, onset, and severity of adverse drug reactions (ADRs). Efficacy was evaluated in terms of the changes in low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), triglyceride (TG), and non-HDL cholesterol (non-HDL-C) levels from the start of combination therapy (baseline) to the last observation carried forward (LOCF). Lipid levels were assessed at 1, 3, 6, and 12 months after starting combination therapy.

Results

We enrolled 665 patients in this observational study. Safety was evaluated in 659, and ADRs occurred in 42 patients (6.4%). The most frequent ADRs were blood creatine phosphokinase increase (1.5%) and myalgia (0.8%). Asymptomatic gallstones were observed in four patients (0.6%). Effectiveness was evaluated in 622 patients. LDL-C, HDL-C, TG, and non-HDL-C levels improved significantly from baseline to LOCF by −17.4%, 8.8%, –40.5%, and −21.6%, respectively (all, p < 0.001). Lipid levels also improved from baseline to each evaluation time-point.

Conclusions

Bezafibrate in combination with ezetimibe is safe and effective, and is potentially useful for comprehensive management of dyslipidemia.

Impact of dose frequency on compliance and health outcomes: a literature review (1966-2006)

In order for treatments to be effective, patients must be compliant with their medication regimens. Currently, patient compliance is seen as one of the most challenging issues in treating patients with chronic diseases. Studies in which dose frequency has been changed have been reviewed across several different diseases to examine the impact of a change in dose frequency on compliance and health outcomes, as well as efficacy and tolerability. In general, reducing dose frequency may improve medication compliance and effectiveness, and reduce adverse events, while possibly reducing healthcare costs. Suggestions for future research have been presented, including a need to measure compliance with injectable formulations and a standardized definition of compliance.

Niacin extended-release therapy in phase III clinical trials is associated with relatively low rates of drug discontinuation due to flushing and treatment-related adverse events: a pooled analysis

BACKGROUND AND OBJECTIVE

Niacin is a highly effective agent for increasing low high-density lipoprotein cholesterol (HDL-C) levels. It also has beneficial effects on key pro-atherogenic lipoprotein parameters. However, the side effect of flushing can challenge patient adherence to treatment. In this study, we pooled safety data from available trials of at least 16 weeks' duration to evaluate the impact of flushing on patient adherence to niacin extended-release (NER) therapy.

METHODS

Data were pooled from eight NER studies (administered as NER with a maximum dosage of 1000, 1500, and 2000 mg/day, either as monotherapy or in combination with simvastatin 20 or 40 mg/day [NER/S], or lovastatin 20 or 40 mg/day [NER/L]) to evaluate rates of study discontinuation due to flushing or any treatment-related adverse events.

RESULTS

While 66.6% of patients experienced flushing, only 5.2% of patients discontinued treatment due to flushing. Of the total number of patients treated with NER (n = 307), NER/S (n = 912), or NER/L (n = 928), 34 (11%), 105 (11%), and 127 (14%) patients discontinued due to any treatment-related adverse event, respectively, while 14 (5%), 43 (5%), and 55 (6%) discontinued due to flushing. Discontinuation for flushing did not differ with regard to maximum dose, or to the presence or type of statin combined with NER.

CONCLUSION

Although flushing was common with NER treatment, discontinuation due to flushing occurred in only 5-6% of patients in this pooled analysis. This could be due to several factors, including the fact that all patients in the NER trials were educated about flushing and its management. Translation of methodology employed in these trials into clinical practice may improve long-term adherence to NER therapy, which would enhance the therapeutic benefit of NER for reducing cardiovascular risk.

The ezetimibe controversy: implications for clinical practice

Low-density lipoprotein cholesterol (LDL-C) remains the primary target of lipid-lowering therapy. Achieving LDL-C goals as outlined by the National Cholesterol Education Program Adult Treatment Panel III can be difficult with statins alone; therefore, adjunctive therapy is often indicated to reduce cardiovascular risk. Ezetimibe, a potent inhibitor of intestinal cholesterol absorption, has been shown to be safe, tolerable and effective at lowering LDL-C, non-high-density lipoprotein cholesterol and apolipoprotein B, each of which has been correlated with improved clinical outcomes, alone or in combination with a statin. However, because of randomized trials that demonstrated mixed results about atherosclerotic plaque regression via carotid intima-media thickness and a concern about cancer risk, ezetimibe's role in lipid therapy has been questioned. Currently, a large randomized controlled trial is in progress to answer if ezetimibe improves clinical outcomes in patients with high-risk acute coronary syndrome. A smaller trial in patients with chronic kidney disease demonstrated reduced clinical events, including myocardial infarction, stroke and revascularization for patients taking the combination of ezetimibe and simvastatin versus those taking statin or placebo alone. In this paper, we review the trials that have led to the ezetimibe controversy and then discuss the possible role of ezetimibe in specific patient populations until the results of ongoing clinical trials are known.

Low high-density lipoprotein cholesterol: current status and future strategies for management

Atherosclerotic cardiovascular disease is the foremost cause of death and disability in the Western world, and it is rapidly becoming so in the developing nations. Even though the use of statin therapy aiming at the low-density lipoprotein cholesterol (LDL) has significantly reduced cardiovascular events and mortality, substantial residual cardiac events still occur in those being treated to the currently recommended targets. In fact, residual risk is also seen in those who are treated “aggressively” such as the “high risk” patients so defined by the National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATP III). Consequently, one must look for the predictors of risk beyond LDL reduction. High-density lipoprotein cholesterol (HDL) is the next frontier. The protectiveness of elevated HDL against atherosclerosis is well described in the literature. HDL subdues several atherogenic processes, such as oxidation, inflammation, cell proliferation and thrombosis. It also helps mobilize the excess LDL via reverse cholesterol transport. Low levels of HDL have been shown to be independent predictors of risk. Thus, therapies to raise the HDL hold promise for additional cardiac risk reduction. In this regard, several randomized trials have recently tested this hypothesis, especially in patients at high risk. In addition to the use of aggressive lifestyle modification, clinical outcomes have been measured following augmentation of HDL levels with various treatment modalities, including aggressive statin therapy, combination therapy with fibrates and niacin, and direct HDL-raising drug treatments. These data for low HDL as an independent risk factor and as the new treatment target are reviewed in this paper.

Utilization patterns of extended-release niacin in Canada: analysis of an administrative claims database

BACKGROUND AND OBJECTIVE

To evaluate utilization patterns with extended-release niacin (ERN) compared with those observed with other lipid-modifying drugs (LMDs).

METHODS

A random sample of 17% of patients who had at least one LMD dispensation between January 2004 and February 2007 was obtained from the administrative databases of the Régie de l'assurance maladie du Quebec. Primary outcomes included drug adherence, persistence and discontinuation with ERN and other LMDs, and daily maintenance dose attainment (1500 mg and 2000 mg) with ERN at one-year follow-up. Adherence was defined as the sum of days of all dispensations divided by the total number of days of follow-up. Persistence was defined as renewal of prescription before the end of dispensation plus a grace period (50% prescription duration).

RESULTS

Among 26,862 patients, the majority received statins (73.4%), whereas 867 (3.2%) received ERN. The mean age of ERN patients was 62 years and 75% were male. After one year, adherence with ERN was below that of statins (62.0% versus 74.9%), as was persistence (36.1% versus 46.7%), while discontinuation rates were higher (64.0% versus 53.3%). The median time until discontinuation for ERN was shorter than for statins (66 days versus 99 days). After one year, 5.8% of patients were taking 1500 mg or more and 3.2% were on 2000 mg.

CONCLUSIONS

In the present cohort of patients from regular clinical practice in Quebec, ERN use was associated with low prescription rates, inferior adherence and persistence compared with other LMDs, high discontinuation rates, and very low 2000 mg dose attainment.

Drug treatment of hyperlipidaemia: a guide to the rational use of lipid-lowering drugs

Mammalian sterol and lipid metabolism depends on a large number of highly evolved biochemical and histological processes responsible for the absorption, distribution and steady-state anabolic/catabolic handling of these substances. Lipoproteins are complex polymolecular assemblies comprising phospholipids, cholesterol and cholesterol esters, triglycerides and a variety of apolipoproteins. The primary function of lipoproteins is to facilitate the systemic distribution of sterols and lipids. Abnormalities in lipoprotein metabolism are quite common and are attributable to a large number of genetic mutations, metabolic derangements such as insulin resistance or thyroid dysfunction, and excess availability of cholesterol and fat from dietary sources. Dyslipidaemic states facilitate endothelial dysfunction and atherogenesis. Dyslipidaemia is recognized as a risk factor for cardiovascular disease in both men and women, and people of all racial and ethnic groups throughout the world. Dyslipidaemia is modifiable with dietary change and the use of medications that impact on lipid metabolism through a variety of mechanisms. Reducing atherogenic lipoprotein burden in serum is associated with significant and meaningful reductions in risk for a variety of cardiovascular endpoints, including myocardial infarction, ischaemic stroke, development of peripheral arterial disease and mortality. This review provides an overview on how to best position lipid-lowering drugs when attempting to normalize serum lipid profiles and reduce risk for cardiovascular disease. HMG-CoA reductase inhibitors (statins) are widely accepted to be the agents of choice for reducing serum levels of low-density lipoprotein cholesterol (LDL-C) in both the primary and secondary prevention settings. Ezetimibe and bile acid sequestrants are both effective agents for reducing LDL-C, either used alone or in combination with statins. The statins, fibric acid derivatives (fibrates) and niacin raise high-density lipoprotein cholesterol to different extents depending upon genetic and metabolic background. Fibrates, niacin and omega-3 fish oils are efficacious therapies for reducing serum triglycerides. Combinations of these drugs are frequently required for normalizing mixed forms of dyslipidaemia.

Treating mixed hyperlipidemia and the atherogenic lipid phenotype for prevention of cardiovascular events

Statins reduce cardiovascular events and cardiovascular and total mortality in persons at risk for and with coronary disease, but there remains a significant residual event rate, particularly in those with the atherogenic lipid phenotype that is characterized by a low high-density lipoprotein (HDL) cholesterol and increase in non-HDL cholesterol. Large outcome trials designed to assess the value of combining statins with other agents to target HDL cholesterol and non-HDL cholesterol will not be completed for a few years, but there is ample evidence for the clinician to consider combination therapy. The choices for therapies to supplement statins include niacin, fibrates, and omega-3 fatty acids. We present the argument that after therapeutic lifestyle changes, the first priority should be the maximally tolerated effective dose of a potent statin. Evidence supports the addition of niacin as the second agent. In some situations, high-dose omega-3 fatty acid therapy could be the first agent added to statins. Although fibrate monotherapy alone or in combination with non-statin low-density lipoprotein cholesterol-lowering agents can be effective in mixed hyperlipidemia when statins are not tolerated, the combination of statin+fibrate should be considered second-line therapy until the efficacy and safety are established.

Hepatotoxicity Associated with Metformin Therapy in Treatment of Type 2 Diabetes Mellitus with Nonalcoholic Fatty Liver Disease

Objective:

To report a case of idiosyncratic hepatotoxicity associated with metformin in the treatment of type 2 diabetes with nonalcoholic fatty liver disease (NAFLD).

Case Summary:

A 61-year-old obese man presented with jaundice, nausea, fatigue, and an unintentional weight loss 2 weeks following initiation of metformin. Laboratory findings revealed aminotransferase values 10–15 times the upper limit of normal. Potential causative agents, including metformin, simvastatin, and Niaspan (extended-release niacin), were discontinued. Two months later, the patient's signs and symptoms had resolved and aminotransferase values returned to normal. An objective causality assessment revealed that the adverse reaction was probably associated with metformin.

Discussion:

Since numerous medications and disease states can cause abnormalities in liver enzymes, it is important for providers to be able to distinguish the cause(s) and take appropriate actions. This can take a great deal of time and effort in patients with multiple medications and comorbidities. In this patient's case, viral hepatitis, worsening NAFLD, and the concomitant drugs were highly suspected. As hydroxymethylglutaryl coenzyme A reductase inhibitors offer substantial cardiovascular benefits and as metformin is a first-line agent in helping to lower blood glucose concentrations and to normalize the metabolic profile in type 2 diabetes, reintroduction of metformin and simvastatin would likely be beneficial.

Conclusions:

This is a case report of metformin-induced hepatotoxicity. As the prevalence of type 2 diabetes and subsequent metabolic effects increases in the US, metformin use will likewise increase. As potential for increased idiosyncratic hepatotoxicity associated with metformin use is likely to occur, clinicians should be vigilant.

A "hot" topic in dyslipidemia management--"how to beat a flush": optimizing niacin tolerability to promote long-term treatment adherence and coronary disease prevention

Niacin is the most effective lipid-modifying agent for raising high-density lipoprotein cholesterol levels, but it also causes cutaneous vasodilation with flushing. To determine the frequency of flushing in clinical trials, as well as to delineate counseling and treatment approaches to prevent or manage flushing, a MEDLINE search was conducted of English-language literature from January 1, 1985, through April 7, 2009. This search used the title keywords niacin or nicotinic acid crossed with the Medical Subject Headings adverse effects and human. Niacin flushing is a receptor-mediated, mainly prostaglandin D(2)-driven phenomenon, the frequency, onset, and duration of which are largely determined by the distinct pharmacological and metabolic profiles of different niacin formulations. Subjective assessments include ratings of redness, warmth, itching, and tingling. In clinical trials, most (>60%) niacin users experienced mild or moderate flushing, which tended to decrease in frequency and severity with continued niacin treatment, even with advancing doses. Approximately 5% to 20% of patients discontinued treatment because of flushing. Flushing may be minimized by taking niacin with meals (or at bedtime with a low-fat snack), avoiding exacerbating factors (alcohol or hot beverages), and taking 325 mg of aspirin 30 minutes before niacin dosing. The current review advocates an initially slow niacin dose escalation from 0.5 to 1.0 g/d during 8 weeks and then from 1.0 to 2.0 g in a single titration step (if tolerated). Through effective counseling, treatment prophylaxis with aspirin, and careful dose escalation, adherence to niacin treatment can be improved significantly. Wider implementation of these measures should enable higher proportions of patients to reach sufficient niacin doses over time to prevent cardiovascular events.

Interventions to improve adherence to lipid lowering medication

BACKGROUND

Lipid lowering drugs are still widely underused, despite compelling evidence about their effectiveness in the treatment and prevention of cardiovascular disease. Poor patient adherence to a medication regimen is a major factor in the lack of success in treating hyperlipidaemia. In this updated review we focus on interventions which encourage patients at risk of heart disease or stroke to take lipid lowering medication regularly.

OBJECTIVES

To assess the effects of interventions aimed at improved adherence to lipid lowering drugs, focusing on measures of adherence and clinical outcomes.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, Issue 1), MEDLINE, EMBASE, PsycINFO and CINAHL (March 2008). No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled trials of adherence-enhancing interventions for lipid lowering medication in adults for both primary and secondary prevention of cardiovascular disease in an ambulatory setting looking at adherence, serum lipid levels, adverse effects and health outcomes. Studies were selected independently by two review authors.

DATA COLLECTION AND ANALYSIS

Data were extracted and assessed by two review authors following criteria outlined by the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

Three additional studies were found in the update and, in total, 11 studies were included in this review. The studies included interventions that caused a change in adherence ranging from -3% to 25% (decrease in adherence by 3% to increase in adherence by 25%). Patient re-enforcement and reminding was the most promising category of interventions, investigated in six trials of which four showed improved adherent behaviour of statistical significance (absolute increase: 24%, 9%, 8% and 6%). Other interventions associated with increased adherence were simplification of the drug regimen (absolute increase 11%) and patient information and education (absolute increase 13%). The methodological and analytical quality of some studies was low and results have to be considered with caution.

AUTHORS' CONCLUSIONS

At this stage, reminding patients seems the most promising intervention to increase adherence to lipid lowering drugs. The lack of a gold standard method of measuring adherence is one major barrier in adherence research. More reliable data might be achieved by newer methods of measurement, more consistency in adherence assessment and longer duration of follow up. More recent studies have started using more reliable methods for data collection but follow-up periods remain too short. Increased patient-centredness with emphasis on the patient's perspective and shared decision-making might lead to more conclusive answers when searching for tools to encourage patients to take lipid lowering medication.

What's the deal with niacin development: is laropiprant add-on therapy a winning strategy to beat a straight flush?

PURPOSE OF REVIEW

Niacin is a B-complex vitamin used as a lipid-altering drug since the 1950s. Niacin improves multiple lipid parameters. Atherosclerotic coronary heart disease outcome studies support niacin's efficacy in reducing coronary heart disease events, either as monotherapy or when used in combination with other lipid-altering drugs. The most commonly reported reason for the lack of its more widespread clinical use is niacin-induced flushing.

RECENT FINDINGS

Laropiprant is a highly selective prostaglandin D2 receptor 1 antagonist that mitigates niacin-induced flushing.

SUMMARY

This review examines the history and provides a perspective regarding the extended-release niacin/laropiprant development program, which was designed to better allow patients to achieve a more therapeutic niacin dose of 2 g/day, without the need for titration. Ongoing coronary heart disease outcome studies will provide better insight as to the benefits of niacin in general, and the safety and efficacy of extended-release niacin/laropiprant specifically.

Review of extended-release niacin/laropiprant fixed combination in the treatment of mixed dyslipidemia and primary hypercholesterolemia

Although statins reduce cardiovascular morbidity and mortality further risk reduction is needed. In this respect low HDL-cholesterol concentrations and/or elevated triglyceride concentrations may be potential treatment targets. Niacin (nicotinic acid) is an effective drug which increases the plasma concentration of high-density lipoprotein (HDL)-cholesterol and decreases the concentration of low-density lipoprotein (LDL)-cholesterol, triglycerides and lipoprotein(a). Clinical studies indicate that niacin can significantly reduce the risk for cardiovascular events. However, niacin is not very commonly used because of significant side effects (especially flushing). Laropiprant is a potent selective antagonist of PGD2-receptor subtype-1 and can thus reduce niacin-induced flushing. Although the addition of laropiprant will reduce the frequency of flushing, it will not completely eliminate this side effect. Laropiprant does not change the effect of niacin on lipids or other side effects of niacin (ie, gastro-intestinal problems, glucose elevation). The combination of niacin with laropiprant may therefore enable use of niacin at higher doses and therefore exploit the full potential of the drug. Endpoint studies that will be published over the next few years will show whether this treatment modality also translates into clinical effect in patients treated with statins. Until publication of these studies niacin/laropiprant should be used only in high-risk patients not achieving lipid goals on statins.

Transition probabilities and predictors of adherence in a California Medicaid population using antihypertensive and lipid-lowering medications

OBJECTIVES

To determine adherence rates, transition probabilities, and factors associated with transition from higher to lower adherence in antihypertensive (AH) and lipid-lowering (LL) medications.

METHODS

California Medicaid data (1995-2003) were used to identify hypertensive patients with prescriptions for both AH and LL medications. Proportion of days covered (PDC) was used to define three adherence classifications: fully adherent (FA, PDC >or= 0.8), partially adherent (PA, 0.2 <or= PDC < 0.8), and nonadherent (NA, PDC < 0.2). Annual transition matrices documented the probability of adherence status changes.

RESULTS

Only 13% of the 5943 patients were FA to both drugs at baseline. Patients who were FA (60%) or NA (84%) to both drugs had high probability of maintaining status at year two (Y2). Significant variables associated with a transition from adherent to NA at Y2 included African American race (odds ratio [OR] 1.5), other race groups (OR 1.2), lack of Medicare eligibility (OR 1.3), and initiating LL therapy of fibric acid derivatives (OR 1.3) or niacin (OR 1.8).

CONCLUSIONS

Patients FA or NA with both drugs at baseline were more likely to maintain their adherence status. Race, insurance coverage, and type of LL medication were significantly associated with transitioning from any adherence status to nonadherence. These findings may be useful in guiding cost-effectiveness analyses incorporating adherence estimates.

Current and emerging paradigms in the therapeutic management of atherosclerosis

BACKGROUND

The pathogenesis of atherosclerosis lies in abnormalities in lipoprotein metabolism leading to pathological interactions with vessel walls and the release of inflammatory components, which further aggravate the disease condition.

OBJECTIVE

To elucidate current and emerging trends in drug discovery towards the development of new entities regulating lipoprotein metabolism and inflammatory components to combat the progression of atherosclerosis.

METHODS

Research/review articles in the public domain and press releases were employed.

RESULTS/CONCLUSION

With the recent failure of torcetrapib and succinobucol, drug discovery and development efforts towards the treatment of atherosclerosis have received a big jolt and have been slowed down to a certain extent [corrected]. But this could be a starting point for several new mechanisms that are emerging to discover new drugs to combat the disease.

Long-term safety and efficacy of a combination of niacin extended release and simvastatin in patients with dyslipidemia: the OCEANS study

INTRODUCTION

High-dose HMG-CoA reductase inhibitors (statins) fail to prevent approximately two-thirds of cardiovascular events. This fact has focused increased attention on treating abnormalities of non-high-density lipoprotein-cholesterol (non-HDL-C), HDL-C, and triglycerides in national guidelines and has intensified interest in combination therapy.

METHODS

The OCEANS study (Open-label evaluation of the safety and efficacy of a Combination of niacin ER and simvAstatin in patieNts with dySlipidemia; ClinicalTrials.gov identifier: NCT00080275) evaluated the safety and efficacy of a combination of niacin extended release and simvastatin (NER/S; SIMCOR) over 52 weeks in 520 patients with mixed dyslipidemia. After a >or=4-week run-in phase of diet modification and simvastatin 40 mg/day, median baseline values (mg/dL) were: non-HDL-C = 141, low-density lipoprotein-cholesterol (LDL-C) = 110, HDL-C = 45, and triglyceride = 151. Patients were randomized to an 8- or 12-week niacin titration scheme to a maximum NER/S dosage of 2,000/40 mg/day.

RESULTS

Differences between titration groups in tolerability, safety, and efficacy were minimal; therefore, all results are for pooled titration groups. The safety of NER/S was consistent with the safety profile of each individual component. Treatment with NER/S was well tolerated: 71% of patients experienced flushing and 92% of flushing episodes were mild or moderate in intensity. Overall, 61% of patients experienced flushing episodes that were rated as mild or moderate in intensity. Flushing decreased over time: <40% of those who had flushing during titration experienced flushing during the final 12 weeks. A total of 20% of patients discontinued treatment because of a treatment-related adverse event, including 7% who discontinued because of flushing. Median changes from baseline (following the simvastatin 40 mg/day run-in phase) to 24 weeks were: non-HDL-C = -27.3%, LDL-C = -25.0%, HDL-C = +23.9%, and triglycerides = -35.9% (all p < 0.0001 vs baseline). In lipid-treatment-naive patients, NER/S 2,000/40 mg/day decreased non-HDL-C, LDL-C, and triglycerides by approximately 50% and increased HDL-C by approximately 25% when week-24 lipid values were compared with lipid values obtained prior to the simvastatin 40 mg/day run-in. All three therapeutic lipid targets (LDL-C [risk-adjusted goal], HDL-C >or=40 mg/dL, and triglycerides <150 mg/dL) were achieved concurrently by 65% of patients treated with NER/S.

CONCLUSION

Treatment with NER/S 2,000/40 mg/day is well tolerated, has no unanticipated adverse events, and provides additional, clinically relevant improvements in multiple lipid parameters beyond statin monotherapy.

The pharmacokinetics and disposition of MK-0524, a Prostaglandin D2receptor 1 antagonist, in rats, dogs and monkeys

MK-0524 is a potent, selective and orally active Prosglandin D(2) Receptor 1 (DP(1)) antagonist currently under clinical development for the treatment of niacin-induced flushing. Experiments to study the pharmacokinetics, metabolism and excretion of MK-0524 were conducted in rats, dogs and monkeys. MK-0524 displayed linear kinetics and rapid absorption following an oral dose. Following intravenous (i.v.) administration of MK-0524 to rats and dogs (1 and 5 mg/kg), the mean Cl(p) was approximately 2 and approximately 6 ml/min/kg, the T(1/2) was approximately 7 and approximately 13 h and the Vd(ss) was approximately 1 and approximately 5 L/kg, respectively. In monkeys dosed i.v. at 3 mg/kg, the corresponding values were 8 ml/min/kg, 3 h and 1 L/kg, respectively. Following oral dosing of MK-0524 to rats (5, 25 and 100 mg/kg), dogs (5 mg/kg) and monkeys (3 mg/kg), the absorption was rapid with the mean C(max) occurring between 1 and 4 h. Absolute oral bioavailability values in rats, dogs and monkeys were 50, 70 and 8%, respectively. The major circulating metabolite was the acyl glucuronide of MK-0524 (M2), with ratios of glucuronide to the parent aglycone being highest in the monkey followed by dog and rat. In bile duct-cannulated rats and dogs, MK-0524 was eliminated primarily via acyl glucuronidation followed by biliary excretion of the acyl glucuronide, M2, the major drug-related entity in bile.

Reducing coronary risk by raising HDL-cholesterol: risk modelling the addition of nicotinic acid to existing therapy

BACKGROUND AND OBJECTIVES

Reduction in total cholesterol (TC) and LDL-cholesterol (LDL-C) forms one of the principal objectives of most cardiovascular secondary prevention strategies. Many patients being treated with statins, however, have significant residual dyslipidaemia, with many having suboptimal HDL-cholesterol (HDL-C) levels. The addition of nicotinic acid to a statin has been shown to improve this profile, although clinical outcome evidence is currently lacking. This study set out to model the impact of nicotinic acid therapy on cardiovascular risk in these patients, based on Framingham risk assessments on a cohort of patients drawn from UK general practitioner records.

METHODS

Cardiovascular risk profiles were extracted from a research database of 602,222 patients from 98 UK general practices. 23 262 statin-treated patients with established cardiovascular disease or diabetes were identified and their 4-year Framingham risk was estimated. Patients who had either TC or HDL-C outside the desirable range then had their lipid profile adjusted in accordance with the likely performance of nicotinic acid, and the Framingham risk was then re-assessed.

RESULTS

Baseline 4-year coronary risk in the group as a whole was 11.5% (95%CI: 11.4-11.6). After adjustment of the lipid profile, this was reduced to 9.7% (95%CI: 9.6-9.8), a reduction in risk of 15.9% (95%CI: 15.1-16.6). When modelling was limited to those with diabetes or an abnormal treated lipid profile, the magnitude of change was increased to 23-29% depending on sex and subgroup.

CONCLUSIONS

Risk factor modelling suggests that raising HDL-C levels using nicotinic acid in statin-treated patients is likely to yield significant incremental clinical benefits. The results of clinical trials currently under way are awaited with interest.

Niacin use and cutaneous flushing: mechanisms and strategies for prevention

Niacin, or nicotinic acid, has established efficacy for the treatment of dyslipidemia, but the clinical use of niacin has been limited by cutaneous flushing, a well-recognized associated adverse effect. Flushing has been cited as the major reason for the discontinuation of niacin therapy, estimated at rates as high as 25%-40%. A number of studies have established that moderate doses of prostaglandin inhibitors reduce the cutaneous flushing response from niacin administration. Other strategies for reducing flushing include regular consistent dosing, the use of extended-release formulations, patient education, dosing with meals or at bedtime, and the avoidance of alcohol, hot beverages, spicy foods, and hot baths or showers close to or after dosing. Because niacin has recognized cardiovascular benefits, promoting patient awareness of factors that can minimize niacin-induced flushing can help enhance the tolerability of this valuable dyslipidemic agent.

Present-day uses of niacin: effects on lipid and non-lipid parameters

Existing guidelines for the prevention and treatment of coronary artery disease focus on lowering low-density lipoprotein cholesterol (LDL-C) as the primary lipid target. However, there has been increasing interest in raising high-density lipoprotein cholesterol (HDL-C) due to strong evidence linking low HDL-C levels with an increased risk of atherosclerosis. Raising HDL-C levels with lifestyle changes and pharmacologic interventions appear to reduce the risk of coronary artery disease beyond that of lowering LDL-C alone. Niacin has a substantial HDL-C raising effect, and also may beneficially alter total cholesterol, LDL-C and triglyceride levels. Niacin also exhibits antioxidant, anti-inflammatory and other beneficial effects on atherosclerosis. Niacin is safe and effective to use in women, in patients with diabetes mellitus and/or metabolic syndrome, and when used in combination with statins. Niacin has the promise of being a powerful pharmacologic agent in the fight against atherosclerotic disease, although additional clinical studies are required to examine this further.

Niacin in cardiovascular prevention: mechanisms, efficacy, and safety

PURPOSE OF REVIEW

This review describes niacin's mechanism of action, efficacy in cardiovascular prevention, and safety.

RECENT FINDINGS

A G-protein-coupled receptor [GPR109A/HM74A, mouse PUMA-G (protein upregulated in macrophages by interferon-gamma)] was found to mediate the antilipolytic effect of niacin via inhibition of adenylyl cyclase in adipocytes. The same receptor in skin Langerhans cells mediates the common flushing side effect. The endogenous ligand for the receptor may be beta-hydroxybutyrate. Among nine controlled clinical trials using niacin, mostly combined with other drugs, statistically significant positive impact on clinical or anatomic cardiovascular end-points was found in seven, which represents a remarkably consistent record of benefit. Although niacin induces insulin resistance, deterioration of glycemic control in diabetes is usually minor, and there is no evidence of increased incidence of new onset diabetes. Hepatic toxicity is common with higher doses of sustained-release niacin but rare with immediate-release and extended-release niacin at doses up to 2000 mg/day. Extended-release and immediate-release niacin do not substantially potentiate myopathic effects when given in combination with statins.

SUMMARY

Recently developed understanding of the mechanisms, efficacy, and safety of niacin, along with progress in reducing the chief side effect of flushing, should enhance the use of this valuable agent for cardiovascular prevention.

Absorption, metabolism, and excretion of [(14)C]MK-0524, a prostaglandin D(2) receptor antagonist, in humans

[(3R)-4-(4-Chlorobenzyl)-7-fluoro-5-(methylsulfonyl)-1,2,3,4-tetrahydrocyclopentaindol-3-yl]acetic acid (MK-0524) is a potent orally active human prostaglandin D(2) receptor 1 antagonist that is currently under development for the prevention of niacin-induced flushing. The metabolism and excretion of [(14)C]MK-0524 in humans were investigated in six healthy human volunteers following a single p.o. dose of 40 mg (202 microCi). [(14)C]MK-0524 was absorbed rapidly, with plasma C(max) achieved 1 to 1.5 h postdose. The major route of excretion of radioactivity was via the feces, with 68% of the administered dose recovered in feces. Urinary excretion averaged 22% of the administered dose, for a total excretion recovery of approximately 90%. The majority of the dose was excreted within 96 h following dosing. Parent compound was the primary radioactive component circulating in plasma, comprising 42 to 72% of the total radioactivity in plasma for up to 12 h. The only other radioactive component detected in plasma was M2, the acyl glucuronic acid conjugate of the parent compound. The major radioactive component in urine was M2, representing 64% of the total radioactivity. Minor metabolites included hydroxylated epimers (M1/M4) and their glucuronic acid conjugates, which occurred in the urine as urea adducts, formed presumably during storage of samples. Fecal radioactivity profiles mainly comprised the parent compound, originating from unabsorbed parent and/or hydrolyzed glucuronic acid conjugate of the parent compound. Therefore, in humans, MK-0524 was eliminated primarily via metabolism to the acyl glucuronic acid conjugate, followed by excretion of the conjugate into bile and eventually into feces.

Safety considerations with niacin therapy

Niacin has beneficial effects on plasma lipoproteins and has demonstrated clinical benefits in reducing cardiovascular events and atherosclerosis progression. The side effects of niacin, however, have limited its use in general clinical practice. An understanding of cutaneous flushing based on the best available evidence should enhance patient education efforts and improve adherence. Although serious hepatic toxicity from niacin administration has been reported, it is largely confined to the use of slow-release formulations given as unregulated nutritional supplements. Niacin has been shown to induce insulin resistance in short-term trials, but the glycemic response in subjects with and without diabetes is usually minor. Niacin can be used safely in patients with diabetes. Despite a few case reports of myopathy associated with niacin-statin (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor) combination therapy, 2 decades of clinical evidence since the introduction of statins do not support a general myopathic effect of niacin either alone or in combination with statins. Rare, less well-defined side effects of niacin include blurred vision due to cystoid macular edema, nausea and vomiting, and the exacerbation of peptic ulcers. Laboratory abnormalities that are usually small (< or =10%) and clinically unimportant include increased prothrombin time, increased uric acid, and decreases in platelet count and serum phosphorus. Overall, the perception of niacin side effects is often greater than the reality. As a result, a valuable medication for cardiovascular risk is underused.

Metabolism of MK-0524, a prostaglandin D2 receptor 1 antagonist, in microsomes and hepatocytes from preclinical species and humans

(3R)-4-(4-Chlorobenzyl)-7-fluoro-5-(methylsulfonyl)-1,2,3,4-tetrahydrocyclopenta[b]indol-3-yl acetic acid (MK-0524) is a potent orally active human prostaglandin D(2) receptor 1 antagonist that is currently under development for the prevention of niacin-induced flushing. The major in vitro and in vivo metabolite of MK-0524 is the acyl glucuronic acid conjugate of the parent compound, M2. To compare metabolism of MK-0524 across preclinical species and humans, studies were undertaken to determine the in vitro kinetic parameters (K(m) and V(max)) for the glucuronidation of MK-0524 in Sprague-Dawley rat, beagle dog, cynomolgus monkey, and human liver microsomes, human intestinal microsomes, and in recombinant human UDP glucuronosyltransferases (UGT). A comparison of K(m) values indicated that UGT1A9 has the potential to catalyze the glucuronidation of MK-0524 in the liver, whereas UGT1A3 and UGT2B7 have the potential to catalyze the glucuronidation in the intestine. MK-0524 also was subject to phase I oxidative metabolism; however, the rate was significantly lower than that of glucuronidation. The rate of phase I metabolism was ranked as follows: rat approximately monkey > human intestine > dog > human liver with qualitatively similar metabolite profiles across species. In all the cases, the major metabolites were the monohydroxylated epimers (M1 and M4) and the keto-metabolite, M3. Use of inhibitory monoclonal antibodies and recombinant human cytochromes P450 suggested that CYP3A4 was the major isozyme involved in the oxidative metabolism of MK-0524, with a minor contribution from CYP2C9. The major metabolite in hepatocyte preparations was the acyl glucuronide, M2, with minor amounts of M1, M3, M4, and their corresponding glucuronides. Overall, the in vivo metabolism of MK-0524 is expected to proceed via glucuronidation, with minor contributions from oxidative pathways.

Clinical evidence for use of acetyl salicylic acid in control of flushing related to nicotinic acid treatment

Nicotinic acid (NA) is highly effective and widely used in the management of dyslipidaemia. For many patients, the side effect of flushing of the face and upper body leads to discontinuation. Flushing with NA is mediated by prostaglandins, and as acetyl salicylic acid (ASA, 'aspirin') is a highly effective inhibitor of prostaglandin synthesis, there is a rationale for its use to prevent or reduce the severity of NA-related flushing. This literature survey identified four studies specifically exploring the utility of ASA in preventing NA-related flushing in healthy volunteers. Twenty-three NA studies, where ASA was mandatory or optional within the protocol, and four studies, where background ASA therapy was reported in most participants, were also identified. Although the incidence of flushing in studies using ASA was often high, discontinuation rates due to flushing were low (mean 7.7%). This figure compares favourably with discontinuation rates with NA commonly reported in the literature (up to approximately 40%). There is good supportive evidence for the use of ASA in reducing the severity of NA-related flushing.

Statin safety: an overview and assessment of the data--2005

The 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, or statin drugs, have been studied in numerous controlled human research trials involving hundreds of thousands of study participants. Statins have been prescribed for millions of patients. Based on this vast research and clinical experience, statins have been shown to improve lipid blood levels and reduce atherosclerotic coronary artery disease (CAD) risk, resulting in reduced CAD morbidity and mortality, and in several studies, reduced overall ("all-cause") mortality. From a safety perspective, both research trial evidence and clinical practice experience have demonstrated that statins are generally well tolerated. However, as with all pharmaceuticals, safety considerations exist with both monotherapy and combination statin therapy, mainly involving potential adverse effects on muscle, liver, kidney, and the nervous system. The evidence supporting statin-related potential adverse experiences on these organ systems is sometimes strong and based on clear clinical trial evidence (such as the increased risk of muscle enzyme elevation with higher statin doses). The evidence is at other times more speculative, being based on case reports and inconclusive clinical trial data (such as possible favorable or unfavorable effects of statins on cognition). Because the use of statins is so widespread, it is useful for the clinician to understand statin safety issues and the level of available evidence supporting the contention that various adverse effects are caused by statins. This review presents an assessment of statin safety based on an overview of the current statin safety data and their clinical implications.

Nicotinic acid: the broad-spectrum lipid drug. A 50th anniversary review

Nicotinic acid has, like the Roman God Janus, two faces. One is the vitamin. The other is the broad-spectrum lipid drug. The Canadian pathologist Rudolf Altschul discovered 50 years ago that nicotinic acid in gram doses lowered plasma levels of cholesterol. From the point of view of treatment of the dyslipidaemias that are risk factors for clinical atherosclerosis nicotinic acid is a miracle drug. It lowers the levels of all atherogenic lipoproteins--VLDL and LDL with subclasses as well as Lp(a)--and in addition it raises more than any other drug the levels of the protective HDL lipoproteins. Trials have shown that treatment with nicotinic acid reduces progression of atherosclerosis, and clinical events and mortality from coronary heart disease. The new combination treatment with statin-lowering LDL and nicotinic acid-raising HDL is reviewed. A basic effect of nicotinic acid is the inhibition of fat-mobilizing lipolysis in adipose tissue leading to a lowering of plasma free fatty acids, which has many metabolic implications which are reviewed. The very recent discovery of a nicotinic acid receptor and the finding that the drug stimulates the expression of the ABCA 1 membrane cholesterol transporter have paved the way for exciting and promising new 50 years in the history of nicotinic acid.