Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0016382 (flushing)
 6,387 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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.
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PMID:Niacin use and cutaneous flushing: mechanisms and strategies for prevention. 1837 36

The efficacy and safety of 2 regimens of a combination of a proprietary niacin extended release plus simvastatin (NER/S; 1,000/20 and 2,000/20 mg/day) were compared with simvastatin monotherapy (20 mg/day) for 24 weeks in 319 high-risk patients with predominantly mixed dyslipidemia who were already at National Cholesterol Education Program Adult Treatment Panel III risk-adjusted goals for low-density lipoprotein cholesterol. After a run-in on simvastatin 20 mg/day, both NER/S doses (1,000/20 and 2,000/20 mg/day) resulted in greater decreases in non-high-density lipoprotein (HDL) cholesterol vs simvastatin 20 mg/day (-13.9% and -22.5% vs -7.4%, respectively; p <0.01). Significant improvements in HDL cholesterol, triglycerides, apolipoprotein B, lipoprotein(a), and total/HDL cholesterol ratio were also observed. Patients with hypertriglyceridemia (triglycerides > or =200 mg/dl) typically had greater lipid responses to NER/S with the notable exception that HDL cholesterol responses to NER/S were similar in those with or without increased triglycerides. Treatment with both doses of NER/S was well tolerated; < or =60% of patients in any treatment group experienced flushing, >90% of flushing was mild or moderate in intensity, and only 7.5% of patients in both NER/S treatment groups discontinued because of flushing. The safety of NER/S was consistent with the safety profile of each individual component. In conclusion, this study showed that NER/S provided additional clinically relevant improvements in multiple lipid parameters and was safe and well tolerated.
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PMID:Comparison of the safety and efficacy of a combination tablet of niacin extended release and simvastatin vs simvastatin monotherapy in patients with increased non-HDL cholesterol (from the SEACOAST I study). 1847 54

The discovery and profiling of 3-(1H-tetrazol-5-yl)-1,4,5,6-tetrahydro-cyclopentapyrazole (5a, MK-0354), a partial agonist of GPR109a, is described. Compound 5a retained the plasma free fatty acid lowering effects in mice associated with GPR109a agonism, but did not induce vasodilation at the maximum feasible dose. Moreover, preadministration of 5a blocked the flushing effect induced by nicotinic acid but not that induced by PGD2. This profile made 5a a suitable candidate for further study for the treatment of dyslipidemia.
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PMID:3-(1H-tetrazol-5-yl)-1,4,5,6-tetrahydro-cyclopentapyrazole (MK-0354): a partial agonist of the nicotinic acid receptor, G-protein coupled receptor 109a, with antilipolytic but no vasodilatory activity in mice. 1866 82

Treatment with niacin effectively improves multiple lipid parameters and cardiovascular outcomes. Widespread use of niacin, however, is limited by flushing, which is mediated primarily by prostaglandin D2 (PGD2). Laropiprant is a selective PGD2 receptor 1 (DP1) antagonist that reduces objective measures of niacin-induced flushing symptoms upon initiation of therapy and with more chronic use. Results from early dosing and formulation studies have culminated in the development of a combination extended-release (ER) niacin/laropiprant tablet aimed at providing the beneficial lipid-modifying effects of niacin, while reducing niacin-induced flushing. The improvement in the tolerability of niacin with ER niacin/laropiprant allows niacin dosing to initiate directly at 1 g and rapidly advance to a 2-g target dose. ER niacin/laropiprant generally is tolerated well and represents a new treatment option for dyslipidemia that offers the potential for more patients to receive the lipid-modifying and cardiovascular benefits of niacin.
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PMID:Extended-release niacin/laropiprant: reducing niacin-induced flushing to better realize the benefit of niacin in improving cardiovascular risk factors. 1903 52

Niacin has long been used in the treatment of dyslipidemia and cardiovascular disease. Recent research on niacin has been focused on understanding the mechanism of action of niacin and preparation of safer niacin formulations. New findings indicate that niacin does the following: 1) it inhibits hepatic diacylglycerol acyltransferase 2, resulting in inhibition of triglyceride synthesis and decreased apolipoprotein B-containing lipoproteins; 2) it decreases the surface expression of hepatic adenosine triphosphate synthase beta-chain, leading to decreased holoparticle high-density lipoprotein catabolism and increased high-density lipoprotein levels; and 3) it increases redox potential in arterial endothelial cells, resulting in inhibition of redox-sensitive genes. Flushing, an adverse effect of niacin, results from niacin receptor GPR109A-mediated production of prostaglandin D2 and E2 via DP1 and EP2/4 receptors. DP1 receptor antagonist (laropiprant) attenuates the niacin flush. A reformulated preparation of extended-release niacin (Niaspan; Abbott, Abbott Park, IL) lowers flushing compared with an older Niaspan formulation. These advancements in niacin research have rejuvenated its use for the treatment of dyslipidemia and cardiovascular disease.
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PMID:Niacin: an old drug rejuvenated. 1908 Jul 27

Nicotinic acid is one of the most effective agents for both lowering triglycerides and raising HDL. However, the side effect of cutaneous flushing severely limits patient compliance. As nicotinic acid stimulates the GPCR GPR109A and Gi/Go proteins, here we dissected the roles of G proteins and the adaptor proteins, beta-arrestins, in nicotinic acid-induced signaling and physiological responses. In a human cell line-based signaling assay, nicotinic acid stimulation led to pertussis toxin-sensitive lowering of cAMP, recruitment of beta-arrestins to the cell membrane, an activating conformational change in beta-arrestin, and beta-arrestin-dependent signaling to ERK MAPK. In addition, we found that nicotinic acid promoted the binding of beta-arrestin1 to activated cytosolic phospholipase A2 as well as beta-arrestin1-dependent activation of cytosolic phospholipase A2 and release of arachidonate, the precursor of prostaglandin D2 and the vasodilator responsible for the flushing response. Moreover, beta-arrestin1-null mice displayed reduced cutaneous flushing in response to nicotinic acid, although the improvement in serum free fatty acid levels was similar to that observed in wild-type mice. These data suggest that the adverse side effect of cutaneous flushing is mediated by beta-arrestin1, but lowering of serum free fatty acid levels is not. Furthermore, G protein-biased ligands that activate GPR109A in a beta-arrestin-independent fashion may represent an improved therapeutic option for the treatment of dyslipidemia.
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PMID:beta-Arrestin1 mediates nicotinic acid-induced flushing, but not its antilipolytic effect, in mice. 1934 87

Flushing symptoms limit the use of niacin as an effective treatment for dyslipidemia; laropiprant, a prostaglandin D2 receptor subtype 1 antagonist, reduces niacin-induced flushing and is being developed in combination with niacin. The aims of this study were to both determine the effect of renal insufficiency on plasma pharmacokinetics of laropiprant and to assess safety and tolerability in patients with severe renal insufficiency. This open-label study compared the pharmacokinetics of a single laropiprant 40-mg dose in 8 nondialyzed, severe renal insufficiency patients (RIs) with healthy matched subjects (HSs) (24-hour creatinine clearance <30 mL/min/1.73 m(2) and >80 mL/min/1.73 m(2) for RIs and HSs, respectively). In RIs, laropiprant was well tolerated and the area under the concentration time curve (AUC(0-infinity)) was modestly higher (ratio of geometric least-squares means [GMR] for RIs to HSs was 1.58; 90% confidence interval [CI], 1.06-2.35); neither the maximum laropiprant plasma concentration (C(max)) nor the time to C(max) (T(max)) was significantly affected. The apparent terminal half-life (t(1/2)) was 26.0 and 14.8 hours for RIs and HSs, respectively (P = 0.007). Similarly, for the inactive laropiprant glucuronide metabolite, the GMR for AUC(0-infinity) was 2.17 (90% CI, 1.44-3.27), and the apparent t(1/2) values were 25.3 to 14.5 hours (P = 0.037) in RIs and HSs, respectively. Renal insufficiency had no clinically significant effect on laropiprant pharmacokinetics. Because niacin and its metabolites are excreted through the kidneys, the combination of niacin with laropiprant should be used with caution in patients with renal impairment.
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PMID:Pharmacokinetics of laropiprant and glucuronide metabolite in patients with severe renal insufficiency. 1943 74

Laropiprant (LRPT), a prostaglandin D2 receptor 1 antagonist shown to reduce niacin-induced flushing symptoms, is being developed in combination with niacin for the treatment of dyslipidemia. This study assessed the pharmacokinetics/pharmacodynamics of single-dose warfarin in the presence/absence of multiple-dose LRPT. Thirteen subjects received 2 treatments in random order separated by > or =10-day washout: (1) multiple-dose LRPT 40 mg/d for 12 days (days -5 to 7) with coadministered single-dose warfarin 30 mg (day 6) and (2) single-dose warfarin 30 mg (day 1). R+- and S(-)-warfarin and international normalized ratio (INR) were assayed predose and up to 168 hours postdose. Comparability was declared if the 90% confidence intervals (CIs) for the geometric mean ratio (GMR; warfarin + LRPT/warfarin alone) of area under the plasma concentration curve from zero to infinity (AUC0-infinity) for R+- and S(-)-warfarin were contained within (0.80, 1.25). The estimated GMRs of AUC0-infinity (90% CIs) were 1.02 (0.96, 1.09) and 1.04 (0.98, 1.09) for R+- and S(-)-warfarin, respectively. The estimated GMRs of maximum plasma concentration (Cmax) (90% CIs) were 1.13 (1.02, 1.26) and 1.11 (0.99, 1.24) for R+- and S(-)-warfarin, respectively. The estimated GMRs of area under the prothrombin time INR curve from 0 to 168 hours on day 21 (INR AUC0-168 h) and average maximum observed prothrombin time INR (INRmax) were 1.02 (0.99, 1.05) and 1.04 (0.98, 1.10), respectively. There was no evidence of clinically meaningful alterations in the pharmacokinetics and pharmacodynamics (ie, INR) of R(+)- or S(-)-warfarin after coadministration of multiple-dose LRPT and single-dose warfarin.
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PMID:Influence of laropiprant, a selective prostaglandin D2 receptor 1 antagonist, on the pharmacokinetics and pharmacodynamics of warfarin. 1945 60

Niacin has beneficial effects on a patient's lipid and lipoprotein profiles and cardiovascular risk, particularly at doses >2 g/day, but is underused due to flushing. Laropiprant (LRPT), a selective prostaglandin D(2) receptor-1 antagonist, decreases flushing associated with extended-release niacin (ERN). We compared flushing with ERN/LRPT dosed by a simplified 1-g --> 2-g regimen versus gradually titrated niacin extended-release (N-ER; given as NIASPAN, trademark of Kos Life Sciences LLC). Patients with dyslipidemia (n = 1,455) were randomized 1:1 to ERN/LRPT (1 g for 4 weeks advanced to 2 g for 12 weeks) or N-ER (0.5 g for 4 weeks titrated in 0.5-g increments every 4 weeks to 2 g for the final 4 weeks). Aspirin/nonsteroidal anti-inflammatory drugs were allowed to mitigate flushing. Flushing severity was assessed using the validated Global Flushing Severity Score (GFSS; none 0, mild 1 to 3, moderate 4 to 6, severe 7 to 9, extreme 10). Patients on ERN/LRPT, despite more rapid niacin titration, had less flushing than those on N-ER, as measured by number of days per week with moderate or greater GFSS across the treatment period (p <0.001). More than 2 times as many patients had no episodes of moderate, severe, or extreme flushing (GFSS > or =4) with ERN/LRPT than with N-ER (47.0% vs 22.0%, respectively) across the treatment period. Fewer patients on ERN/LRPT discontinued due to flushing than those on N-ER (7.4% vs 12.4%, p = 0.002). Other than the decrease in flushing, the safety and tolerability profile of ERN/LRPT was similar to that of N-ER. In conclusion, improvement in flushing with ERN/LRPT versus gradually titrated N-ER supports a rapidly advanced 1-g --> 2-g dosing regimen, allowing patients to start at 1 g and quickly reach and tolerate the optimal 2 g dose of ERN.
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PMID:Flushing profile of extended-release niacin/laropiprant versus gradually titrated niacin extended-release in patients with dyslipidemia with and without ischemic cardiovascular disease. 1957 24

Laropiprant, an antagonist of the PGD(2) receptor, DP1, is effective in reducing the flushing symptoms associated with extended-release (ER) niacin and thereby improves the tolerability of niacin therapy for dyslipidemia. Because PGD(2) has been reported to inhibit platelet aggregation in vitro, it has been speculated that antagonism of DP1 may enhance platelet reactivity. Three clinical studies evaluated the potential effect of laropiprant, with or without coadministration of ER niacin, on in vivo platelet function in healthy subjects and hypercholesterolemic or diabetic subjects by measuring urinary levels of 11-dehydrothromboxane B(2) (11-dTxB(2)), a marker of in vivo platelet activation. Following 7 days of multiple-dose administration, coadministration of laropiprant with ER niacin did not increase urinary 11-dTxB(2) levels compared to ER niacin alone in healthy, hypercholesterolemic, or diabetic subjects. In hypercholesterolemic and diabetic subjects, laropiprant did not increase urinary 11-dTxB(2) levels compared to placebo. These results demonstrate that laropiprant does not enhance in vivo platelet reactivity, either alone or in combination with niacin.
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PMID:Laropiprant in combination with extended-release niacin does not alter urine 11-dehydrothromboxane B2, a marker of in vivo platelet function, in healthy, hypercholesterolemic, and diabetic subjects. 1983 61


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