Discovery and characterization of GSK256073, a non-flushing hydroxy-carboxylic acid receptor 2 (HCA2) agonist.

Niacin has been used for many years in the treatment of dyslipidemia due to its ability to decrease serum levels of triglycerides and low-density lipoprotein cholesterol and to increase levels of high density lipoprotein cholesterol. However, niacin causes severe flushing resulting in poor patient compliance. The discovery of hydroxy-carboxylic acid receptor 2 (HCA2) as a high affinity receptor for niacin has opened avenues to investigate the mechanism of action of niacin, and to potentially discover agonists which maintain the antilipolytic effects of niacin accessed by a decrease in circulating non-esterified fatty acids (NEFA) and thereby perhaps the lipid/lipoprotein effects, but avoid the flushing effects. Here we describe the strategy we implemented to identify such compounds. This approach resulted in the discovery of GSK256073, a highly potent HCA2 agonist, which produced similar NEFA lowering effects to niacin in preclinical models (rat and guinea pig). A guinea pig model was used to predict flushing, via an increase in ear temperature, and GSK256073 was found to have a minimal effect in this model. These preclinical models appeared to be predictive of human response, since in a first-time-in-human study, GSK256073 displayed long lasting NEFA and triglyceride lowering effects in healthy male subjects, which were not associated with flushing. GSK256073 can be used as a pharmacological tool to better understand the role of HCA2 in lipid metabolism.

Flushing and pruritus secondary to prescription fish oil ingestion in a patient with allergy to fish.

BACKGROUND: A brand of fish oil capsules contains omega-3 fatty acids obtained from several fish sources. Although the manufacturer calls for caution in patients with fish hypersensitivity, insufficient data is available to make a definitive recommendation regarding its use in this population. CASE PRESENTATION: A patient with documented seafood allergy presented to the emergency department 4 days after the initiation of prescription brand name fish oil capsules complaining of chest tightness, shortness of breath, tingling of upper extremities, flushing, and pruritus that was minimally relieved by excessive nonprescription diphenhydramine administration. During subsequent follow-up, the patient reported that all symptoms had resolved within 5 days of discontinuing the medication and 3 days of disposing of her pillbox and all medications that had come in contact with the fish oil capsules. CONCLUSION: Due to the patient's allergic history, timing of onset/offset of the reaction, laboratory evidence, and the use of the Naranjo probability scale, prescription fish oil capsules were deemed the probable cause of this patient's pruritus and flushing of the face and trunk. Practitioners and patients should always ensure they have an updated list of allergies within the patient's medical record that includes medications as well as foods and food additives.

Benefits and harm of niacin and its analog for renal dialysis patients: a systematic review and meta-analysis.

PURPOSE: Clinical trials have shown that niacin and its analog, niacinamide, significantly reduce serum phosphate in patients undergoing dialysis. This review aimed to assess the benefits and harm of niacin and niacinamide in renal dialysis patients. METHODS: PubMed, EMBASE, and Cochrane Library were searched, without language limitation, randomized controlled trials (RCTs). Standard methods, consistent with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, were used. Reviewer Manager software, version 5.2, was used for meta-analysis. RESULTS: Five RCTs with a sample size of 230 patients were included. The meta-analysis showed that niacin and niacinamide significantly decreased serum phosphorus levels [weight mean difference (WMD) -0.88; 95 % confidence interval (CI) -1.19 to -0.57] as well as the calcium × phosphorus product (Ca × P) (WMD -9.15; 95 % CI -13.23 to -5.08), and increased high-density lipoprotein (HDL) levels (WMD 9.30; 95 % CI 5.86-12.74) in renal dialysis patients. Niacin significantly increased the risk of flushing [relative risk (RR) 33; 95 % CI 4.71-232.12] in these patients, while the risk of thrombocytopenia was significantly increased in the niacinamide group (RR 2.82; 95 % CI 1.14-6.94). However, sensitivity analysis showed that our finding regarding thrombocytopenia should be regarded with a low degree of certainty. CONCLUSION: Niacin and its analog effectively improved phosphorus metabolism in renal dialysis patients. However, niacin can cause flushing and niacinamide probably cause thrombocytopenia. Further larger sample size and well-designed RCTs are needed.

Apple pectin for the reduction of niacin-induced flushing.

BACKGROUND: Niacin, or vitamin B3, when used in high doses can significantly improve the levels of all major lipoproteins. Despite these benefits, the use of niacin is greatly limited secondary to benign yet bothersome cutaneous flushing primarily involving the face and upper extremities. Pretreatment with aspirin or other prostaglandin inhibitors has demonstrated significant reductions in niacin-induced flushing (NIF), but other treatment options are needed. Clinical and anecdotal evidence suggests the ingestion of pectin-containing fruits (eg, apple) mitigates NIF; however, clinical trials evaluating this are nonexistent. OBJECTIVE: That pretreatment with encapsulated apple pectin would limit the incidence, severity, time of initiation, and duration of NIF. METHODS: We enrolled 100 niacin-naïve subjects (n = 25 per group) and preteated them in a double-blind manner with apple pectin, apple pectin + aspirin, aspirin, or placebo, followed by a one-time 1000 mg dose of niacin extended-release (niacin ER). Subjects then assessed major flushing parameters hourly for the next 6 hours with a validated visual analog scale. RESULTS: Apple pectin and aspirin each significantly lowered the duration of NIF and produced nonsignificant but positive improvements in all other major flushing parameters compared with placebo. CONCLUSION: Apple pectin may potentially be an alternative to aspirin for the prevention of NIF. Larger trials are needed to further evaluate the benefit of pectin on NIF.

Combination treatment with atorvastatin plus niacin provides effective control of complex dyslipidemias: a literature review.

Patients with dyslipidemia receive a cardiovascular benefit from lowering low-density lipoprotein cholesterol (LDL-C). Atorvastatin is currently one of the most effective approved medications for lowering LDL-C, and has been shown to significantly reduce cardiovascular risk in many patient groups. However, even with substantial lowering of LDL-C with atorvastatin, patients still have a residual risk for coronary heart disease. Elevated triglyceride levels and low high-density lipoprotein cholesterol (HDL-C) levels may contribute to this risk. Approved medications targeting these secondary lipid parameters include fibrates, omega-3 fatty acids, and niacin. Among these medications, niacin provides the optimal increase in HDL-C levels and has efficacy similar to the other medications in lowering triglyceride levels. However, there are challenges to adherence with niacin treatment. The most common challenge during niacin treatment is flushing, although it typically decreases with ongoing use and can be ameliorated by pretreatment with aspirin and counseling by the prescriber. A combination of atorvastatin and niacin may provide more complete normalization of the lipid profile and increased cardiovascular benefits. A literature review of the PubMed and Embase databases was conducted for clinical studies that reported on the lipid-modifying efficacy of the atorvastatin plus niacin combination. Identified studies involved patients at risk for coronary heart disease and patients with established coronary heart disease. Overall, the studies were small but indicated that atorvastatin in combination with niacin was efficacious in normalizing lipid parameters. Larger lipid studies as well as studies evaluating cardiovascular outcomes during atorvastatin plus niacin treatment are warranted.

Important considerations for treatment with dietary supplement versus prescription niacin products.

Niacin is a water-soluble B vitamin (B3) known to have favorable effects on multiple lipid parameters, including raising high-density lipoprotein cholesterol (HDL-C) levels and lowering triglycerides (TGs), lipoprotein(a), and low-density lipoprotein cholesterol (LDL-C). Although LDL-C remains the primary target of lipid-altering therapy, current guidelines emphasize HDL-C and other modifiable lipid factors as key secondary targets. Thus, niacin is considered an important therapeutic option to help reduce the risk of cardiovascular disease in patients with mixed dyslipidemia who, in addition to high LDL-C, have elevated TGs and low HDL-C. Although available prescription niacin products, including immediate-release niacin (IR; Niacor) and an extended-release niacin formulation (Niaspan), have demonstrated safety and efficacy in randomized clinical trials, confusion remains among health care providers and their patients regarding the various commercially available nonprescription dietary supplement niacin products. These dietary supplements, which include IR, sustained-release (SR), and "no-flush" or "flush-free" niacin products, are not subject to the same stringent US Food and Drug Administration regulations as prescription drugs. In fact, both the American Heart Association and the American Pharmacists Association recommend against the use of dietary supplement niacin as a substitute for prescription niacin. Although some dietary supplement IR and SR niacin products have demonstrated a lipid response in clinical trials, products labeled as "no-flush" or "flush-free" that are intended to avoid the common niacin-associated adverse effect of flushing generally contain minimal or no free, pharmacologically active niacin and therefore lack beneficial lipid-modifying effects. To clarify important differences between available prescription and dietary supplement niacin products, this article contrasts current regulatory standards for dietary supplements and prescription drugs and provides an overview of available clinical data from key trials of niacin.

Pleiotropic effects of nicotinic acid: beyond high density lipoprotein cholesterol elevation.

AIMS: Treatment with statins has significantly reduced cardiovascular morbidity and mortality, an effect attributed to both the low-density lipoprotein cholesterol (LDL-C) lowering capacity and the pleiotropic actions of these drugs. However, residual risk remains even after intense LDL-C lowering. Therefore, additional treatment with lipid-lowering drugs which improve other lipid parameters and have favourable non-lipid effects may be of clinical value. The aim of the present article is to review the actions of nicotinic acid and comment on the limitations and possible benefits of this drug in clinical practice. METHODS: Relevant articles were identified through a Pubmed search up to July 2010. RESULTS: Nicotinic acid (niacin) improves the lipid profile and has been associated with reduction in morbidity and mortality from cardiovascular disease. This favourable outcome may be due to several beneficial actions of this drug, such as antithrombotic, anti-inflammatory and antioxidant. However, its use has been limited due to side effects, especially flushing. A novel formulation with a prostaglandin D2 receptor antagonist (laropiprant) appears to substantially decrease the frequency and intensity of flushing, without affecting the other properties of niacin. Some concerns regarding treatment with nicotinic acid include impaired glucose metabolism and elevations in uric acid and homocysteine levels. CONCLUSION: Nicotinic acid is a safe supplementary (to statins) lipid lowering agent which may also improve cardiovascular outcomes. Whether its combination with laropiprant will be proved equally effective and more favourable in terms of adverse effects remains to be established by large clinical trials.

Salvia divinorum: exposures reported to a statewide poison control system over 10 years.

BACKGROUND: Salvia divinorum, a hallucinogenic herb, has in recent years become popular among teenagers and young adults. Salvia is presently marketed as a "legal" alternative to other drugs of abuse, but little is known about the clinical toxicity of this substance. OBJECTIVES: The purpose of this study is to describe the clinical and demographic features of this emerging substance of recreational abuse using data obtained from the records of a poison control center. METHODS: We performed retrospective review of exposures to the herbal hallucinogen Salvia divinorum as reported to the California Poison Control System (CPCS) over the last 10 years. Demographic and clinical data were collected and compiled from the computerized records of the CPCS for the search terms "salvia" and "sage." RESULTS: There were 37 exposures to S. divinorum and 96 exposures to non-hallucinogenic Salvia species. Eighteen (49%) of the exposures were to S. divinorum alone. Intentional Salvia exposures resulted in a variety of neurologic, cardiovascular, and gastrointestinal effects. Notably, the use of concomitant substances of abuse was associated with a high rate of complications and psychomotor disturbances. CONCLUSIONS: Intentional use of S. divinorum, whether alone or in combination with alcoholic beverages and other drugs, causes neurologic, cardiovascular, and gastrointestinal effects. This poison-center-based review helps to characterize the clinical toxicity of S. divinorum, but more clinical and pharmacologic research is warranted for this rapidly emerging substance of abuse.

Alterations of niacin skin sensitivity in recurrent unipolar depressive disorder.

INTRODUCTION: Skin flushing after niacin (methylnicotinate, vitamin B(3)) stimulation is a biological marker of availability of polyunsaturated fatty acids (PUFA). Decreased PUFA levels have been reported in depressive disorder, while add-on supplementation of omega-3 PUFA has been suggested to improve depressive symptoms. This study aimed to clarify whether a disturbance of niacin skin flushing occurs also in depression, and to identify patient characteristics for those who might benefit from PUFA supplementation. METHOD: We studied 30 patients with recurrent unipolar depressive disorder during a major depressive episode (treated with antidepressants), and 30 healthy volunteers matched for age and gender. Aqueous methylnicotinate was applied in three dilution steps (0.001M, 0.01M, and 0.1M) onto the inner forearm skin. Skin flushing was assessed in three-minute intervals over 15min using optical reflection spectroscopy. RESULTS: While there was no overall difference in skin flushing between patients and controls, niacin sensitivity was inversely correlated with severity of symptoms, and flush deficits were significantly associated with depressed mood, feelings of anxiety and somatic symptoms (loss of appetite and weight loss). CONCLUSION: Results are suggestive of a subgroup of depressive patients characterised by a specific symptom cluster and disturbed niacin skin flushing.

Investigation of niacin on parameters of metabolism in a physiologic dose: randomized, double-blind clinical trial with three different dosages.

The aim of this double-blind, placebo-controlled cross-over design trial was to assess the safety of a multi-vitamin preparation containing nicotinic acid in a physiological dose. Seventy-two healthy volunteers took part in this trial. At six consecutive time-points, we systematically documented blood pressure, pulse, skin temperature and flushing symptoms after an oral dose of up to 50.1 mg nicotinic acid. The results suggest that nicotinic acid in a dosage of 16.7 mg does not cause flushing symptoms. In higher doses up to 50.1 mg, flushing symptoms are sporadically possible. There was no physiologically relevant change regarding the central metabolic parameters blood pressure, pulse and skin temperature.

Impaired flush response to niacin skin patch among schizophrenia patients and their nonpsychotic relatives: the effect of genetic loading.

We previously reported familial aggregation in flush response to niacin skin patch among schizophrenia patients and their nonpsychotic relatives. However, little is known about whether this abnormal skin response is associated with genetic loading for schizophrenia. This study compared the niacin flush response in subjects from families with only one member affected with schizophrenia (simplex families) with those from families having a sib-pair with schizophrenia (multiplex families). Subjects were patients with schizophrenia and their nonpsychotic first-degree relatives from simplex families (176 probands, 260 parents, and 80 siblings) and multiplex families (311 probands, 180 parents, and 52 siblings) as well as 94 healthy controls. Niacin patches of 3 concentrations (0.001M, 0.01M, and 0.1M) were applied to forearm skin, and the flush response was rated at 5, 10, and 15 minutes, respectively, with a 4-point scale. More attenuated flush response to topical niacin was shown in schizophrenia probands and their relatives from multiplex families than in their counterparts from simplex families, and the differentiation was better revealed using 0.1M concentration of niacin than 0.01M or 0.001M. For the highest concentration of 0.1M and the longest time lag of 15 minutes, a subgroup of probands (23%), parents (27%), and siblings (19%) still exhibited nonflush response. Flush response to niacin skin patch is more impaired in schizophrenia patients and their relatives from families with higher genetic loading for schizophrenia, and this finding has implications for future genetic dissection of schizophrenia.

Phospholipid membrane abnormalities and reduced niacin skin flush response in schizophrenia.

OBJECTIVES: Reduced n-3 and n-6 polyunsaturated fatty acids (PUFAs) content in red blood cell (RBC) membranes and abnormal membrane phospholipid metabolism were repeatedly implicated in the etiology of schizophrenia. FINDINGS: Prenatal and perinatal depletion of PUFAs interferes with normal brain development and function. The lack of docosahexaenoic acid - DHA in the brain is reflected in lower membrane DHA/AA (AA - arachidonic acid) ratio, increased activity of AA-metabolizing enzymes, and disturbance of downstream metabolic pathways involved in signaling, growth modulation, brain glucose uptake, immune functions, neurotransmission, synaptogenesis and neurogenesis. Preliminary high-throughput metabolomic studies revealed abnormal biochemical profile in patients with schizophrenia or brief psychotic disorder when compared to healthy controls. The results of both metabolomic and proteomic studies pointed to energy metabolism and lipid biosynthesis being impaired in schizophrenia. The usefulness of antipsychotic medication and supplementation with PUFAs in reverting to the normal metabolic state has been suggested in early treatment of the first psychotic episode. Abnormalities of phospholipid metabolism can be also detected as attenuated niacin skin flush response in the variety of neuropsychiatric disorders. CONCLUSIONS: Disturbances of lipid homeostasis could represent biochemical markers in the preclinical phase of neuropsychiatric illnesses and could serve as triggers in genetically vulnerable individuals. The assessment of patients' lipid status may also help in monitoring the course of the disease and treatment response. In this regard, simple, cheap and fast niacin skin flush test might be valuable. It might help in diagnosis of adolescents and young adults with psychotic behaviour, or in defining the necessity for long-term antipsychotic therapy. Along with antipsychotic medication schizophrenic patients need specific medical nutrition therapies.

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.

"Flush-free niacin": dietary supplement may be "benefit-free".

This report describes a patient with coronary artery disease who was instructed to take extended-release niacin to treat low high-density lipoprotein cholesterol and instead purchased "flush-free niacin" available at the pharmacy. There was no significant change in his lipids. Once the patient switched to extended-release niacin, the anticipated beneficial effects were seen. The article reviews the composition of flush-free niacin, its purported and real lipid effects, and warns against the effects of misleading marketing.

Clinical observation on Breviscapine in treating hypertension patients complicated with micro-albuminuria of renal impairment.

OBJECTIVE: To evaluate the efficacy of Breviscapine on essential hypertension (EH) patients complicated with micro-albuminuria of renal impairment. METHODS: Seventy-six EH patients were randomly assigned to the control group and the treated group, the former was given amlodipine, captopril/uropidil and the latter was given in addition Breviscapine intravenously dripped for 2 treatment courses. The indexes of serum creatinine (Cr), blood urea nitrogen (BUN), blood and urinary beta(2)-microglobulin (beta(2)-MG), and quantitative determination of 24 hrs urinary protein were evaluated before and after treatment. RESULTS: In the control group, compared with before treatment, the quantitative determination of 24 hrs urinary protein got reduced significantly (P < 0.05), while in the treated group, both urinary beta(2)-MG and quantitative determination of 24 hrs urinary protein got lowered significantly (P < 0.05 and P < 0.01). But after treatment, compared with the control group, urinary beta(2)-MG and quantitative determination of 24 hrs urinary protein in the treated group were obviously reduced (P < 0.05). CONCLUSION: Besides lowering blood pressure effectively, Breviscapine could improve the renal function significantly and reduce the urinary micro-albuminuria, hence showing promising effect on renal protection.

Sildenafil citrate ingestion in a pediatric patient.

BACKGROUND: Sildenafil citrate is the first FDA-approved oral agent for male erectile dysfunction. Common adverse effects include flushing, headache, and dyspepsia, although more serious side effects have been reported. Because of its specific therapeutic indication, sildenafil toxicity has been limited almost exclusively to adults. We report a symptomatic case of pediatric sildenafil ingestion. CASE: A 2-year-old male ingested 75 mg of sildenafil citrate (Viagra) 2 hours prior to arrival at an emergency room. Ipecac syrup had been given at home with one episode of vomiting. Activated charcoal was considered but withheld due to the delayed presentation to the hospital. The patient was observed in the hospital for 17.5 hours. Observed clinical effects included facial flushing, transient penile engorgement, bilateral rhonchi, and diarrhea. No significant cardiovascular effects were seen. A bronchodilator was given with resolution of rhonchi. No other specific interventions were required. One day after discharge, the patient had one additional bout of diarrhea and complained of pain in the penile region for one day. Two weeks after the exposure, the patient's mother denied any unusual symptoms. CONCLUSION: Pediatric ingestion of sildenafil may result in mild symptoms including persistent flushing and penile engorgement with associated pain. Penile pain may persist even after resolution of the erection. It is questionable whether the respiratory symptoms and diarrhea were related since neither has been described following sildenafil exposure. Significant cardiovascular symptoms were not seen. Early administration of ipecac syrup did not prevent symptoms from developing.

Complementary and alternative therapies for advanced prostate cancer.

This article reviews complementary and alternative therapies for advanced prostate cancer. This is not a comprehensive survey of nontraditional therapies for prostate cancer. Rather, this review focuses on alternative and complementary therapies with published studies to evaluate efficacy and safety. Three areas are addressed: alternative forms of hormonal therapy, management of side effects of hormonal therapy, and management of skeletal complications.