Atorvastatin. A review of its pharmacology and therapeutic potential in the management of hyperlipidaemias

Coenzyme Q10 remarkably improves the bio-energetic function of rat liver mitochondria treated with statins

CoQ10 shares a biosynthetic pathway with cholesterol therefore it can be a potential target of the widely available lipid-lowering agents such as statins. Statins are the most widely prescribed cholesterol-lowering drugs with the ability to inhibit HMG-CoA (3-hydroxy-3-methylglutaryl-coenzyme A) reductase. Preclinical and clinical safety data have shown that statins do not cause serious adverse effects in humans. However, their long-term administration is associated with a variety of myopatic complaints. The aim of this study was to investigate whether CoQ10 supplementation of animals under high fat diet (HFD) treated with statins is able to bypass the mitochondrial metabolic defects or not? Animals were divided into 7 groups and fed with either regular (RD) or HFD during experiments. The first group considered as regular control and fed with a RD. Groups 2-7 including HFD control, CoQ10 (10mg/kg), simvastatin (30mg/kg), atorvastatin (30mg/kg), simvastatin+CoQ10 or atorvastatin+CoQ10 treated orally for 30 days and fed with HFD. At the end of treatments, the animals were killed and blood samples were collected for biochemical examinations. The rat liver mitochondria were isolated and several mitochondrial indices including succinate dehydrogenase activity (SDA), ATP levels, mitochondrial membrane potential (MMP) and mitochondrial permeability transition pore (MPP) were determined. We found that triglyceride (Tg), cholesterol (Chol) and low-density lipoprotein (LDL) were augmented with HFD compared to RD and treatment with statins remarkably lowered the Tg, Chol and LDL levels. Mitochondrial parameters including, SDA, ATP levels, MMP and MPP were reduced with statin treatment and improved by co-administration with CoQ10.

Atorvastatin and trans-caryophyllene for the prevention of leukopenia in an experimental chemotherapy model in Wistar rats

Malignant neoplasia represents the second cause of disease-related mortality and, among all patients diagnosed with cancer, 70% will receive chemotherapy during the course of treatment. As a consequence, an increasing number of researchers have focused their attention on the search for more specific anticancer therapies associated with fewer side effects. Leukopenia is an important adverse effect associated with chemotherapy. Secondary infection is very common among leukopenic patients, directly affecting the continuity of the chemotherapeutic treatment and leading to possible complications in tumor immune defense. Atorvastatin, a type of statin, is a known agent used to control hypercholesterolemia. Trans-caryophyllene, isolated from a resinous oil extracted from the copaiba tree, possesses anti-inflammatory and analgesic properties. The AIM of the present study was to evaluate, through a complete leukocyte count, the systemic immunomodulation potential of pentoxifylline (PTX), atorvastatin and trans-caryophyllene, as well as the possible prophylactic role of these drugs against secondary leukopenia, in an experimental chemotherapy model induced by 5-fluorouracil (5-FU) in wistar rats. A total of 32 male wistar rats were used, 24 of which were submitted to treatment with atorvastatin, PTX and trans-caryophyllene prior to the administration of chemotherapy. The Shapiro-Wilk test was used to verify normality and the Kruskal-Wallis test was used for negative data in the normality test. Among the drugs selected, atorvastatin exhibited the best preventive potential in regards to leukopenia secondary to experimental chemotherapy induced by 5-FU, in comparison to the group receiving saline solution, while PTX amplified such alterations in the leukograms of the animals in this trial.

Characterisation of selected active agents regarding pKa values, solubility concentrations and pH profiles by SiriusT3

The aim of this work was to determine pKa values and solubility properties of 34active agents using the SiriusT3 apparatus. The selected drug substances belong to the groups of ACE-inhibitors, β-blockers, antidiabetics and lipid lowering substances. Experimentally obtained pKa and intrinsic solubility values were compared to calculated values (program ACD/ChemSketch) and pKa values to published data as well. Solubility-pH profiles were generated to visualise the substance solubility over the gastrointestinal pH range. The relationship between the solubility characteristic of a substance, its bioavailability and categorisation according to the Biopharmaceutics Classification System (BCS) was examined as well. The results showed a good agreement between experimentally obtained, calculated and published pKa values. The measured and calculated intrinsic solubility values indicated several major deviations. All solubility-pH profiles showed the expected shape and appearance for acids, bases or zwitterionic substances. The obtained results for the pKa and solubility measurements of the examined active agents may help to predict their physicochemical behaviour in vivo, and to understand the bioavailability of the substances according to their BCS categorisation. The easy and reproducible determination of pKa and solubility values makes the SiriusT3 apparatus a useful tool in early stages of drug and formulation development.

Effect of steady-state atorvastatin on the pharmacokinetics of a single dose of colchicine in healthy adults under fasted conditions

BACKGROUND AND OBJECTIVE

Colchicine is commonly prescribed for gout. While minimally metabolized by the cytochrome P450 (CYP) 3A4 isoenzyme, colchicine is a substrate for P-glycoprotein (P-gp). Atorvastatin is metabolized primarily by CYP3A4 and is a P-gp inhibitor. Patients with gout often have dyslipidemia; therefore, the potential for co-administration of atorvastatin and colchicine exists. The objective of this study was to determine the effect of oral atorvastatin on the pharmacokinetics of a single, oral dose of colchicine.

METHODS

Twenty-four healthy adult subjects were enrolled in this single-center, open-label, non-randomized, one-sequence, two-period drug-drug interaction study. On day 1, subjects received a single oral dose of colchicine 0.6 mg. After a 14-day washout, subjects received atorvastatin 40 mg once daily for 14 days followed by a single dose of colchicine 0.6 mg co-administered with atorvastatin 40 mg on day 28. Main outcome measures were colchicine maximum plasma concentration (C max), area under the plasma concentration-time curve (AUC) from time zero to the last measurable concentration (AUC last), and AUC from time zero to infinity (AUC∞), which were compared with and without concurrent atorvastatin.

RESULTS

Colchicine AUC last, AUC∞, and C max increased by 27, 24, and 31 %, respectively, when co-administered with atorvastatin. Corresponding 90 % confidence intervals around the ratios were outside the established no-effect 80-125 % interval.

CONCLUSION

Increased colchicine exposure was observed after a single dose of colchicine was administered with steady-state atorvastatin. Additional studies with multiple dosing of both drugs are needed to further determine the clinical implications of these results.

Metformin enhances the anti-adipogenic effects of atorvastatin via modulation of STAT3 and TGF-β/Smad3 signaling

Adipocyte accumulation is associated with the development of obesity and obesity-related diseases. Interactions of master transcription factors and signaling cascades are required for adipogenesis. Regulation of excessive adipogenic processes may be an attractive therapeutic for treatment of obesity and obesity-related diseases. In this study, we found that atorvastatin exerts an anti-adipogenic activity in 3T3-L1 pre-adipocytes, and that this activity is elevated in combination with metformin. Expression of the adipogenic master regulators PPARγ and C/EBPα, and their target gene aP2, was suppressed by atorvastatin. Furthermore, atorvastatin treatment resulted in increased activation of the key master regulator of cellular energy homeostasis, AMPK. These biological activities of atorvastatin were elevated in combination with metformin. These anti-adipogenic activities were associated with regulation of the STAT3 and TGF-β signaling cascades, resulting in the regulation of the expression of STAT3 target genes, such as KLF5, p53, and cyclin D1, and TGF-β signaling inhibitory genes, such as SMAD7. Our results suggest that combination therapy with atorvastatin and metformin may have therapeutic potential for the treatment of obesity and obesity-related diseases caused by excessive adipogenesis.

Differential effects of Rifampin and Ketoconazole on the blood and liver concentration of atorvastatin in wild-type and Cyp3a and Oatp1a/b knockout mice

Atorvastatin is eliminated by CYP3A4 which follows carrier-mediated uptake into hepatocytes by OATP1B1, OATP1B3, and OATP2B1. Multiple clinical studies demonstrated that OATP inhibition by rifampin had a greater impact on atorvastatin systemic concentration than itraconazole-mediated CYP3A4 inhibition. If it is assumed that the blood and hepatocyte compartments are differentiated by the concentration gradient that is established by OATPs, and if the rate of uptake into the hepatocyte is rate-determining to the elimination of atorvastatin from the body, then it is hypothesized that blood concentrations may not necessarily reflect liver concentrations. In wild-type mice, rifampin had a greater effect on systemic exposure of atorvastatin than ketoconazole, as the blood area under the blood concentration-time curve increased 7- and 2-fold, respectively. In contrast, liver concentrations were affected more by ketoconazole than by rifampin, as liver levels increased 21- and 4-fold, respectively. Similarly, in Cyp3a knockout animals, 39-fold increases in liver concentrations were observed despite insignificant changes in the blood area under the blood concentration-time curve. Interestingly, blood and liver levels in Oatp1a/b knockout animals were similar to wild types, suggesting that Oatp1a/b knockout may be necessary but not sufficient to completely describe atorvastatin uptake in mice. Data presented in this work indicate that there is a substantial drug interaction when blocking atorvastatin metabolism, but the effects of this interaction are predominantly manifested in the liver and may not be captured when monitoring changes in the systemic circulation. Consequently, there may be a disconnect when trying to relate blood exposure to instances of hepatotoxicity because a pharmacokinetic-toxicity relationship may not be obvious from blood concentrations.

Alternate Day versus Once Daily Atorvastatin for Primary Prevention of (CHD) in Naïve Patients of Dyslipidemia

INTRODUCTION

Statins (or HMG-CoA reductase inhibitors) have become drug of choice for raised Low-Density Lipoprotein Cholesterol (LDL-C) in treating. Of these, Atorvastatin, because of its prolonged 3-hydroxy-3-methylglutaryl-coenzyme A (HMG CoA) reductase inhibition has been considered for alternate day therapy in primary prevention of (CHD).

OBJECTIVES

To compare the efficacy and safety of daily versus alternate day 10 mg Atorvastatin on reduction of lipid levels in patients of dyslipidemia and to evaluate the number of patients reaching the target Low-Density Lipoprotein (LDL) goals in these groups.

METHODOLOGY

In this comparative, randomized, parallel group, non-blinded study, 100 naïve dyslipidemic patients in low to moderate risk group as per NCEP ATP (III) Guidelines were divided in two groups. Group A (n=50) received Atorvastatin 10 mg every alternate day for three months and Group B (n=50) received Atorvastatin 10 mg daily for three months. Apart from general examination and baseline investigations, lipid profile was also done. Efficacy was assessed by the percentage reduction in LDL and attainment of LDL goals as per NCEP ATP III Guidelines at the end of the study. Safety of the medication was assessed.

RESULTS

Atorvastatin 10 mg daily produced a significant reduction in Total Cholesterol (TC), LDL, Very Low Density Lipoprotein (VLDL) as compared to Atorvastatin 10 mg alternate day. The increase in the HDL level was also greater with a daily dose as compared to alternate day (but not statistically significant). In Low risk category 86.12 % patients (n=31) on daily dose reached their LDL-C goal vis-a-vis 66.67% (n=18) of patients on alternate day therapy. In the moderate risk category 100 % of daily Atorvastatin patients (n=10) achieved their LDL-C goal versus 33.33% patients (n=4) on alternate day therapy. Adverse events with alternate day therapy (n=4) were less as compared with daily treatment (n=10).

CONCLUSION

Atorvastatin 10 mg daily was found to be safe and efficacious in patients with dyslipidemia compared to an alternate day therapy.

HPLC-DAD Method for the Pharmacokinetic Interaction Study of Atorvastatin with Pioglitazone and Cholestyramine in Wistar Rats

Carotid intima-media thickness is used as a surrogate marker for cardiovascular complications in diabetes mellitus. The combination of atorvastatin and pioglitazone was found to be effective in reducing the thickness of the carotid intima-media layer. The method of RP-HPLC coupled with a diode array detector (DAD) was developed for the pharmacokinetic interaction study of atorvastatin with pioglitazone and cholestyramine, respectively, in Wistar rats. Atorvastatin (ATR) and pioglitazone (PIO) were resolved on a C₁₈ column with a mobile phase composed of 48% methanol, 19% acetonitrile, and 33% 10 mM ammonium formate (v/v/v; pH 3.5±0.3, by formic acid) and a 260 nm detection wavelength on the diode array detector. The method was validated according to international standards with good reproducibility and linear response; mean (r) 0.9987 and 0.9972 to ATR and PIO, respectively. The coefficients of variation of intra- and interassay precision ranged between 4.95–8.12 and 7.29–9.67, respectively. Pharmacokinetic parameters were determined in rats following an oral administration of atorvastatin in the presence and absence of pioglitazone and also with cholestyramine. Compared with the control given atorvastatin alone, the C_max and AUC of atorvastatin were merely unchanged in rats with the co-administration of pioglitazone, while they decreased by nearly 21 and 15%, respectively, with the concurrent use of cholestyramine. There were no significant changes in T_max and the plasma half-life (T_1/2) of atorvastatin in both cases. The performed experiment demonstrated that the presented method was suitable for the estimation and pharmacokinetic interaction study of atorvastatin with pioglitazone and cholestyramine in Wistar rat plasma.

Concise synthesis of atorvastatin lactone under high-speed vibration milling conditions

A Hantzsch-type multicomponent reaction under high-speed vibration milling conditions followed by acid treatment afforded atorvastatin lactone in 38% overall yield.

Nitric oxide-donating atorvastatin attenuates neutrophil recruitment during vascular inflammation independent of changes in plasma cholesterol

PURPOSE

Polymorphonuclear neutrophils, the first leukocytes to infiltrate the inflamed tissue, can make important contributions to vascular inflammatory processes driving the development of atherosclerosis. We herein investigated the effects of atorvastatin and NCX 6560 (a nitric oxide (NO)-donating atorvastatin derivative that has completed a successful phase 1b study) on neutrophilic inflammation in carotid arteries of normocholesterolemic rabbits subjected to perivascular collar placement.

METHODS

Atorvastatin or NCX 6560 were administered orally (5 mg/kg/day or equimolar dose) to New Zealand White rabbits for 6 days, followed by collar implantation 1 h after the last dose. Twenty-four hours later carotids were harvested for neutrophil quantification by immunostaining.

RESULTS

Treatment with NCX 6560 was associated with a lower neutrophil infiltration (-39.5 %), while atorvastatin did not affect neutrophil content. The result was independent of effects on plasma cholesterol or differences in atorvastatin bioavailability, which suggests an important role of NO-related mechanisms in mediating this effect. Consistent with these in vivo findings, in vitro studies showed that NCX 6560, as compared to atorvastatin, had greater inhibitory activity on processes involved in neutrophil recruitment, such as migration in response to IL-8 and IL-8 release by endothelial cells and by neutrophils themselves. Pretreatment with NCX 6560, but not with atorvastatin, reduced the ability of neutrophil supernatants to promote monocyte chemotaxis, a well-known pro-inflammatory activity of neutrophils.

CONCLUSION

Experimental data suggest a potential role of NO-releasing statins in the control of the vascular inflammatory process mediated by polymorphonuclear neutrophils.

Simultaneous quantitation of atorvastatin and its two active metabolites in human plasma by liquid chromatography/(-) electrospray tandem mass spectrometry

A sensitive, accurate and selective liquid chromatography–tandem mass spectrometry method (LC–MS/MS) was developed and validated for the simultaneous quantitation of atorvastatin (AT) and its equipotent hydroxyl metabolites, 2-hydroxy atorvastatin (2-AT) and 4-hydroxy atorvastatin (4-AT), in human plasma. Electrospray ionization (ESI) interface in negative ion mode was selected to improve the selectivity and the sensitivity required for this application. Additionally, a solid phase extraction (SPE) step was performed to reduce any ion-suppression and/or enhancement effects. The separation of all compounds was achieved in less than 6 min using a C₁₈ reverse-phase fused-core^® column and a mobile phase, composed of a mixture of 0.005% formic acid in water:acetonitrile:methanol (35:25:40, v/v/v), in isocratic mode at a flow rate of 0.6 mL/min. The method has lower limit of quantitation (LLOQ) of 0.050 ng/mL for all analytes. The method has shown tremendous reproducibility, with intra- and inter-day precision less than 6.6%, and intra- and inter-day accuracy within ±4.3% of nominal values, for all analytes, and has proved to be highly reliable for the analysis of clinical samples.

Validated spectrophotometric methods for the simultaneous determination of telmisartan and atorvastatin in bulk and tablets

Aim:

Three simple, accurate, and reproducible spectrophotometric methods have been developed and validated for simultaneous estimation of telmisartan (TELM) atorvastatin (ATV) in combined tablet dosage form.

Materials and Methods:

The first method is based on first-order derivative spectroscopy. The sampling wavelengths were 223 nm (zero crossing of TELM) where ATV showed considerable absorbance and 272 nm (zero crossing of ATV) where TELM showed considerable absorbance. The second method Q-analysis (absorbance ratio), involves formation of Q-absorbance equation using respective absorptivity values at 280.9 nm (isobestic point) and 296.0 nm (λmax of TELM). The third method involves determination using multicomponent mode method; sampling wavelengths selected were 296.0 and 246.9 nm.

Results:

TELM and ATV followed linearity in the concentration range of 5–40 and 4–32 μg/ml for method I, 5–30 μg/ml and 2–24 μg/ml for method II and III, respectively. Mean recoveries for all three methods were found satisfactory. All methods were validated according to International Conference on Harmonization Q2B guidelines.

Conclusion:

The developed methods are simple, precise, rugged, and economical. The utility of methods has been demonstrated by analysis of commercially available tablet dosage form.

Promising role of ferulic acid, atorvastatin and their combination in ameliorating high fat diet-induced stress in mice

AIMS

The present study evaluated a comparative and combined hepatoprotective effect of atorvastatin (AS) and ferulic acid (F) against high fat diet (HFD) induced oxidative stress in terms of hyperlipidemia, anti-oxidative status, lipid peroxidation and inflammation.

MAIN METHODS

Male Swiss albino mice were given a diet containing high fat (H) (23.9% wt/wt), supplemented with AS (10mg/kg) or F (100mg/kg) and both (10 and 100mg/kg) for 8weeks. The control mice (C) were fed with normal diet.

KEY FINDINGS

The H mice exhibited increased body weight; hyperlipidemia; serum level of tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6); hepatic lipid profile; lipid accumulation; reactive oxygen species (ROS) of hepatocytes, lipid peroxidation and liver antioxidant capacity was decreased. Immunofluorescent and Western blot assay revealed activation of nuclear factor kappa B (NF-κB) signaling pathway. The addition of F or AS and both in the diet significantly counteracted HFD induced body weight gain; hyperlipidemia; TNF-α, IL-6; hepatic lipid profile; fatty infiltration; NF-κB signaling pathway; ROS; lipid peroxidation and moreover elevated levels of hepatic antioxidant enzymes activity were observed.

SIGNIFICANCE

Simultaneous treatment with AS, F and their combination protected against HFD induced weight gain and oxidative stress. The protection may be attributed to the hypolipidemic and free radical scavenging activity of AS or F and their combination. This study illustrates that AS and F have relatively similar hypolipidemic, antioxidative, anti-inflammatory actions and the AS+F combination along with HFD has shown outstanding effects as compared to other treated groups.

Use of response surface methodology for development of new microwell-based spectrophotometric method for determination of atrovastatin calcium in tablets

BACKGROUND

Response surface methodology by Box-Behnken design employing the multivariate approach enables substantial improvement in the method development using fewer experiments, without wastage of large volumes of organic solvents, which leads to high analysis cost. This methodology has not been employed for development of a method for analysis of atorvastatin calcium (ATR-Ca).

RESULTS

The present research study describes the use of in optimization and validation of a new microwell-based UV-Visible spectrophotometric method of for determination of ATR-Ca in its tablets. By the use of quadratic regression analysis, equations were developed to describe the behavior of the response as simultaneous functions of the selected independent variables. Accordingly, the optimum conditions were determined which included concentration of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), time of reaction and temperature. The absorbance of the colored-CT complex was measured at 460 nm by microwell-plate absorbance reader. The method was validated, in accordance with ICH guidelines for accuracy, precision, selectivity and linearity (r² = 0.9993) over the concentration range of 20-200 μg/ml. The assay was successfully applied to the analysis of ATR-Ca in its pharmaceutical dosage forms with good accuracy and precision.

CONCLUSION

The assay described herein has great practical value in the routine analysis of ATR-Ca in quality control laboratories, as it has high throughput property, consumes minimum volume of organic solvent thus it offers the reduction in the exposures of the analysts to the toxic effects of organic solvents, environmentally friendly "Green" approach) and reduction in the analysis cost by 50-fold.

Effects of D-003 on the Lipid Profile of Patients with Type II Hypercholesterolaemia : A Phase II Clinical Study

BACKGROUND

D-003 is a cholesterol-lowering agent that is isolated and purified from sugarcane wax and has concomitant antiplatelet effects.

OBJECTIVE

To evaluate lipid profile responses to different doses of D-003 in patients with type II hypercholesterolaemia.

STUDY DESIGN

An 8-week, double-blind, placebo-controlled, parallel-group clinical study.

METHODS

After concluding a 5-week diet-only baseline period, 55 patients were randomly allocated to receive either placebo or D-003 at 5, 10, 20 or 40mg once daily with their evening meal for 8 weeks. An interim check-up was performed at week 4. The primary efficacy variable was the reduction of serum low-density lipoprotein-cholesterol (LDL-C) from baseline compared with placebo. Drug safety and tolerability were assessed on the basis of changes in physical, haematological and blood biochemical indicators and on questioning about adverse experiences (AEs).

RESULTS

After 8 weeks of therapy, D-003 significantly lowered (p < 0.0001 vs baseline and placebo) serum LDL-C in a dose-related manner, with reductions of 20.5-26.1% from the lowest to the highest dose investigated. At study completion, 43 of 44 (97.7%) randomised patients treated with D-003 reached LDL-C reductions >15% compared with baseline, while 30 of 44 patients (68.2%) reached LDL-C targets according to their individual global coronary risk status. Decreases in total cholesterol (TC) and the ratios of TC/high-density lipoprotein-cholesterol (HDL-C) and LDL-C/HDL-C were also significant (p < 0.0001) and dose related. Changes in LDL-C, TC and both ratios were significant from the interim check-up. D-003 significantly increased HDL-C values (11.7-16.7%), but the increase was not dose related. No significant changes in lipid profile variables were observed with placebo. D-003 was well tolerated. The treatment did not affect any physical, haematological or blood safety indicators. All included patients completed the study. Four patients reported mild AEs during the study: headache (one patient treated with placebo and one treated with D-003 20 mg/day), insomnia (one patient treated with D-003 5 mg/day) and polyuria (one patient treated with D-003 40 mg/day).

CONCLUSIONS

D-003 was effective in dose dependently reducing LDL-C in patients with type II hypercholesterolaemia, as documented by average percentage reductions and the percentage of patients achieving decreases >15% from baseline and LDL-C goals. The treatment was well tolerated by patients and did not affect any safety indicator. Further studies corroborating these results and exploring the effect of lower doses of D-003 and a longer treatment duration must be carried out, however, before definitive conclusions can be reached. These results encourage continuing clinical investigation on this drug.

Comparison of the effects of policosanol and atorvastatin on lipid profile and platelet aggregation in patients with dyslipidaemia and type 2 diabetes mellitus

BACKGROUND

Diabetes mellitus and hypercholesterolaemia increase the risk for coronary heart disease, with type 2 diabetes mellitus being the most prevalent form of diabetes, frequently accompanied by dyslipidaemia. The main goal of dyslipidaemia control in nondiabetic and diabetic patients is to lower elevated low-density lipoprotein-cholesterol (LDL-C) levels. Policosanol is a cholesterol-lowering drug, purified from sugarcane wax, with a therapeutic range of 5-20 mg/day, which significantly reduces LDL-C levels. Atorvastatin is an HMG-CoA reductase inhibitor that, across its dose range (10-80 mg/day), has shown significantly greater lipid-lowering effects than all previously marketed statins.

OBJECTIVE

To compare the effects on lipid profile and platelet aggregation of policosanol and atorvastatin in patients with dyslipidaemia due to type 2 diabetes.

PATIENTS AND METHODS

This randomised, single-blind, parallel-group study was conducted in patients with type 2 diabetes (fasting glucose </=7 mmol/L and glycosylated haemoglobin [HbA(1c)] <8.5%) and high LDL-C levels (>/=3.0 mmol/L). After 6 weeks on a cholesterol-lowering diet, 40 patients were randomised to policosanol or atorvastatin 10mg tablets taken once daily with the evening meal for 8 weeks. Assessments of lipid profile, platelet aggregation tests, safety indicators and adverse events were performed.

RESULTS

After 8 weeks of therapy, policosanol significantly lowered LDL-C by 25.7% (p < 0.0001 versus baseline) and total cholesterol (TC) by 18.2% (p < 0.001 versus baseline). In turn, atorvastatin 10 mg/day decreased LDL-C by 41.9% and TC by 31.5% (p < 0.0001 versus baseline). Atorvastatin was more effective than policosanol in reducing LDL-C and TC (p < 0.001). Policosanol also significantly reduced the TC/high-density lipoprotein-cholesterol (HDL-C) ratio (25.2%; p < 0.0001) and triglycerides (15.6%; p < 0.001), while atorvastatin lowered TC/HDL-C by 30.5% (p < 0.0001) and triglycerides by 13.9% (p < 0.001); the reductions on these variables were similar in the two groups. Policosanol, but not atorvastatin, significantly increased HDL-C (11.1%; p < 0.01), the effect being significantly different from that of atorvastatin (p < 0.0001). Also, policosanol, but not atorvastatin, significantly inhibited platelet aggregation induced by arachidonic acid 0.75 and 1.5 mmol/L (39.0% and 33.3%, respectively) and by collagen 0.25 and 0.5 mug/mL (15.7% and 28.5%, respectively) [p < 0.001]; these inhibitions were significantly different (p < 0.05) from the changes that occurred with atorvastatin. Neither drug significantly changed platelet aggregation elicited by adenosine diphosphate (ADP). Both treatments were well tolerated, with glycaemic control being unaffected. Neither drug impaired physical safety indicators or glucose control indicators (fasting glucose and HbA(1c)). Atorvastatin significantly increased levels of alanine aminotransferase (ALT) [p < 0.05] and creatine phosphokinase (CPK) [p < 0.01], while policosanol did not significantly change any safety indicator. Only three atorva-statin recipients showed individual values of ALT and CPK that were moderately enhanced (<3 times above the normal upper limit). No patients withdrew from the study. Four patients reported adverse events: two policosanol (insomnia and pruritus) and two atorvastatin (myalgia and raised arterial blood pressure) recipients.

CONCLUSION

Policosanol (10 mg/day) for 8 weeks was less effective than similar doses of atorvastatin in reducing LDL-C and TC in patients with dyslipidaemia due to type 2 diabetes, but more effective in increasing HDL-C. Both drugs similarly reduced the TC/HDL-C ratio and triglycerides. Policosanol showed additional advantages regarding inhibition of platelet aggregation. Nevertheless, further studies of longer duration and using dose-titration schemes to achieve LDL-C goals are needed for wider conclusions about the respective effects of these two drugs in such a population subset.

Pharmacokinetic interaction of garlic and atorvastatin in dyslipidemic rats

Objective:

To assess pharmacokinetic interaction of garlic with atorvastatin in dyslipidemic rats.

Materials and Methods:

Sprague Dawley rats with induced dyslipidemia were divided into five groups of eight rats each. Group 1 was given atorvastatin (10 mg/kg body weight (b.wt) orally), group 2 was given atorvastatin (10 mg/kg b.wt orally)+garlic (1% w/w in feed), group 3 was maintained on atorvastatin (5 mg/kg b.wt orally)+garlic (0.5% w/w in feed), group 4 was maintained on atorvastatin (7.5 mg/kg b.wt orally)+garlic (0.25% w/w in feed), and group 5 was maintained on atorvastatin (2.5 mg/kg b.wt orally)+garlic (0.75% w/w in feed) for 12 weeks. Blood samples were collected at predetermined time intervals for kinetic analysis after the first and last oral dosing of atorvastatin for single and multiple dose studies, respectively. Plasma samples were assayed for atorvastatin concentration by High-Performance Liquid Chromatography (HPLC) and then the concentration-time data were analyzed.

Results:

Maximum observed plasma concentration (C_max), half-life, Area Under Plasma Concentration Time Curve (AUC), and Mean Resident Time (MRT) were significantly (P<0.05) increased during multiple dose kinetic study and elimination rate constant was significantly (P<0.05) decreased in comparison with their respective single-dose values, while there was no significant difference in time to achieve maximum concentration (t_max) in all groups during both phases of the study. The highest values for kinetic parameters were observed in group 2 with correspondingly low activity of Cytochrome P₄₅₀ (CYP₄₅₀).

Conclusion:

The study revealed higher values [C_max, AUC, Area Under The Moment Curve (AUMC), MRT, and half-life] of atorvastatin in garlic-treated groups.

Non-every day statin administration--a literature review

BACKGROUND

Statins are the treatment of choice for lowering LDL-C levels and reducing cardiovascular events. They have a remarkable safety profile, although some patients do not tolerate them. The aim of the study was to summarize the existing data on non-every day statin administration regimens.

METHODS

We searched the MEDLINE databases to identify articles on non-every day statin administration, published between 1990 and January 2010. All publications regardless of methodology, design, size, or language were included. Data extracted included study design, duration and aims, type of statin, therapeutic regimen, patient characteristics, effectiveness, tolerability, and costs.

RESULTS

The 21 retrieved articles were characterized by small sample size, short follow up period, and a preponderance of males and "primary" prevention cases. Several lacked randomization or a control group. The heterogeneity of the study groups, medications, doses, design and aims precluded a pooled or meta-analysis. The most reported and effective regimens were atorvastatin and rosuvastatin on alternate days. These regimens, with or without other lipid lowering agents, were well tolerated even among subjects with previous statin intolerance, and produced meaningful cost savings. Nevertheless, the effectiveness of these regimens on cardiovascular events was not clarified.

CONCLUSIONS

Atorvastatin or rosuvastatin on alternate days might be considered for patients who are intolerant to statin therapy. Further studies are needed to evaluate the effect of these regimens on cardiovascular events.

Validated spectrofluorimetric method for the determination of atorvastatin in pharmaceutical preparations

A rapid, sensitive and simple spectrofluorimetric method was developed for the estimation of atorvastatin. In this method, the native fluorescence characteristics of atorvastatin have been studied in both acidic and basic media. High sensitivity was obtained with 5% acetic acid at 389 nm using 276 nm for excitation. Regression analysis showed a good correlation coefficient (r=0.9995) between fluorescence intensity and concentration over the range of 1.5–4 μg/mL with detection limit of 0.012 μg/mL. The proposed method was successfully applied to the analysis of atorvastatin in pure and pharmaceutical dosage forms with average recovery of 100.29±0.47%. The results were compared favorably with those of the reported method.

Novel microwell-based spectrophotometric assay for determination of atorvastatin calcium in its pharmaceutical formulations

The formation of a colored charge-transfer (CT) complex between atorvastatin calcium (ATR-Ca) as a n-electron donor and 2, 3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as a π-electron acceptor was investigated, for the first time. The spectral characteristics of the CT complex have been described, and the reaction mechanism has been proved by computational molecular modeling. The reaction was employed in the development of a novel microwell-based spectrophotometric assay for determination of ATR-Ca in its pharmaceutical formulations. The proposed assay was carried out in 96-microwell plates. The absorbance of the colored-CT complex was measured at 460 nm by microwell-plate absorbance reader. The optimum conditions of the reaction and the analytical procedures of the assay were established. Under the optimum conditions, linear relationship with good correlation coefficient (0.9995) was found between the absorbance and the concentration of ATR-Ca in the range of 10-150 μg/well. The limits of detection and quantitation were 5.3 and 15.8 μg/well, respectively. No interference was observed from the additives that are present in the pharmaceutical formulation or from the drugs that are co-formulated with ATR-Ca in its combined formulations. The assay was successfully applied to the analysis of ATR-Ca in its pharmaceutical dosage forms with good accuracy and precision. The assay described herein has great practical value in the routine analysis of ATR-Ca in quality control laboratories, as it has high throughput property, consumes minimum volume of organic solvent thus it offers the reduction in the exposures of the analysts to the toxic effects of organic solvents, and reduction in the analysis cost by 50-fold. Although the proposed assay was validated for ATR-Ca, however, the same methodology could be used for any electron-donating analyte for which a CT reaction can be performed.

A validated capillary electrophoresis method for simultaneous determination of ezetimibe and atorvastatin in pharmaceutical formulations

A simple, precise, and sensitive capillary electrophoresis technique coupled with a diode array detector has been developed for the separation and simultaneous determination of ezetimibe and atorvastatin in pharmaceutical formulations. Separation of both ezetimibe and atorvastatin was achieved utilizing fused silica capillary (58 cm × 75 μm ID) and background electrolyte solution that consisted of phosphate buffer (2.5 mM, pH 6.7): methanol (70:30 v/v). The proposed method was validated by testing its specificity, linearity, precision, accuracy, recovery, and detection limit/quantitation limit values. The method was linear over the range 2.5-50 μg/ml for ezetimibe (r = 0.9992) and 1-100 μg/ml for atorvastatin (r = 0.9999). Within-day and between-day RSD for ezetimibe and atorvastatin were ⩽5.6% and ⩽2.9%, respectively. The detection limit was 0.07 μg/ml for ezetimibe and 0.06 μg/ml for atorvastatin. The validated method was successfully employed for the determination of ezetimibe and atorvastatin in tablets with no interfering peaks from common pharmaceutical excipients. The percentage recoveries of the two drugs from their tablets were 99.80 ± 1.76 and 100.19 ± 1.83, respectively.

Effects of HMG-CoA reductase inhibitors on the pharmacokinetics of losartan and its main metabolite EXP-3174 in rats: possible role of CYP3A4 and P-gp inhibition by HMG-CoA reductase inhibitors

The present study was designed to investigate the effects of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (atorvastatin, pravastatin, simvastatin) on the pharmacokinetics of losartan and its active metabolite EXP-3174 in rats. Pharmacokinetic parameters of losartan and EXP-3174 in rats were determined after oral and intravenous administration of losartan (9 mg/kg) without and with HMG-CoA reductase inhibitors (1 mg/kg). The effect of HMG-CoA reductase inhibitors on P-gp and cytochrome (CYP) 3A4 activity were also evaluated. Atorvastatin, pravastatin and simvastatin inhibited CYP3A4 activities with IC₅₀ values of 48.0, 14.1 and 3.10 μmol/l, respectively. Simvastatin (1-10 μmol/l) enhanced the cellular uptake of rhodamine-123 in a concentration-dependent manner. The area under the plasma concentration-time curve (AUC₀₋∞) and the peak plasma concentration of losartan were significantly (p < 0.05) increased by 59.6 and 45.8%, respectively, by simvastatin compared to those of control. The total body clearance (CL/F) of losartan after oral administration with simvastatin was significantly decreased (by 34.8%) compared to that of controls. Consequently, the absolute bioavailability (F) of losartan after oral administration with simvastatin was significantly increased by 59.4% compared to that of control. The metabolite-parent AUC ratio was significantly decreased by 25.7%, suggesting that metabolism of losartan was inhibited by simvastatin. In conclusion, the enhanced bioavailability of losartan might be mainly due to inhibition of P-gp in the small intestine and CYP3A subfamily-mediated metabolism of losartan in the small intestine and/or liver and to reduction of the CL/F of losartan by simvastatin.

4,5-Bis(4-fluoro-phen-yl)-5-hy-droxy-3-(2-methyl-propano-yl)-1-phenyl-pyrrolidin-2-one

The title compound, C₂₆H₂₃F₂NO₃, was synthesized by the reaction of 2-(4-fluoro­benzyl­idene)-4-methyl-3-oxo-N-phenyl­penta­namide and 4-fluoro­benzaldehyde. The dihedral angles between the mean plane through the pyrrolidine ring (nearly planar; maximum deviation of 0.145 Å for the C atom bearing the hydroxy group) with the phenyl and benzene rings are 37.22 (7), 51.88 (7) and 87.64 (9)°, respectively. The pyyolidine ring is near coplaner, with max offset of 0.145 A for C19 atom.\uff09 In the crystal, mol­ecules are linked by pairs of O—H⋯O hydrogen bonds into inversion dimers, which are further assembled into chains parallel to the b axis by weak C—H⋯O hydrogen bonds.

Long-term high-dose atorvastatin decreases brain oxidative and nitrosative stress in a preclinical model of Alzheimer disease: a novel mechanism of action

Alzheimer disease (AD) is an age-related neurodegenerative disorder characterized by progressive memory loss, inability to perform the activities of daily living and personality changes. Unfortunately, drugs effective for this disease are limited to acetylcholinesterase inhibitors that do not impact disease pathogenesis. Statins, which belong to the class of cholesterol-reducing drugs, were proposed as novel agents useful in AD therapy, but the mechanism underlying their neuroprotective effect is still unknown. In this study, we show that atorvastatin may have antioxidant effects, in aged beagles, that represent a natural higher mammalian model of AD. Atorvastatin (80 mg/day for 14.5 months) significantly reduced lipoperoxidation, protein oxidation and nitration, and increased GSH levels in parietal cortex of aged beagles. This effect was specific for brain because it was not paralleled by a concomitant reduction in all these parameters in serum. In addition, atorvastatin slightly reduced the formation of cholesterol oxidation products in cortex but increased the 7-ketocholesterol/total cholesterol ratio in serum. We also found that increased oxidative damage in the parietal cortex was associated with poorer learning (visual discrimination task). Thus, a novel pharmacological effect of atorvastatin mediated by reducing oxidative damage may be one mechanism underlying benefits of this drug in AD.

A new approach to the molecular analysis of docking, priming, and regulated membrane fusion

Studies using isolated sea urchin cortical vesicles have proven invaluable in dissecting mechanisms of Ca(2+)-triggered membrane fusion. However, only acute molecular manipulations are possible in vitro. Here, using selective pharmacological manipulations of sea urchin eggs ex vivo, we test the hypothesis that specific lipidic components of the membrane matrix selectively affect defined late stages of exocytosis, particularly the Ca(2+)-triggered steps of fast membrane fusion. Egg treatments with cholesterol-lowering drugs resulted in the inhibition of vesicle fusion. Exogenous cholesterol recovered fusion extent and efficiency in cholesterol-depleted membranes; α-tocopherol, a structurally dissimilar curvature analogue, selectively restored fusion extent. Inhibition of phospholipase C reduced vesicle phosphatidylethanolamine and suppressed both the extent and kinetics of fusion. Although phosphatidylinositol-3-kinase inhibition altered levels of polyphosphoinositide species and reduced all fusion parameters, sequestering polyphosphoinositides selectively inhibited fusion kinetics. Thus, cholesterol and phosphatidylethanolamine play direct roles in the fusion pathway, contributing negative curvature. Cholesterol also organizes the physiological fusion site, defining fusion efficiency. A selective influence of phosphatidylethanolamine on fusion kinetics sheds light on the local microdomain structure at the site of docking/fusion. Polyphosphoinositides have modulatory upstream roles in priming: alterations in specific polyphosphoinositides likely represent the terminal priming steps defining fully docked, release-ready vesicles. Thus, this pharmacological approach has the potential to be a robust high-throughput platform to identify molecular components of the physiological fusion machine critical to docking, priming, and triggered fusion.

Reduction of liver fructokinase expression and improved hepatic inflammation and metabolism in liquid fructose-fed rats after atorvastatin treatment

Consumption of beverages that contain fructose favors the increasing prevalence of metabolic syndrome alterations in humans, including non-alcoholic fatty liver disease (NAFLD). Although the only effective treatment for NAFLD is caloric restriction and weight loss, existing data show that atorvastatin, a hydroxymethyl-glutaryl-CoA reductase inhibitor, can be used safely in patients with NAFLD and improves hepatic histology. To gain further insight into the molecular mechanisms of atorvastatin's therapeutic effect on NAFLD, we used an experimental model that mimics human consumption of fructose-sweetened beverages. Control, fructose (10% w/v solution) and fructose+atorvastatin (30 mg/kg/day) Sprague-Dawley rats were sacrificed after 14 days. Plasma and liver tissue samples were obtained to determine plasma analytes, liver histology, and the expression of liver proteins that are related to fatty acid synthesis and catabolism, and inflammatory processes. Fructose supplementation induced hypertriglyceridemia and hyperleptinemia, hepatic steatosis and necroinflammation, increased the expression of genes related to fatty acid synthesis and decreased fatty acid β-oxidation activity. Atorvastatin treatment completely abolished histological signs of necroinflammation, reducing the hepatic expression of metallothionein-1 and nuclear factor kappa B binding. Furthermore, atorvastatin reduced plasma (x 0.74) and liver triglyceride (x 0.62) concentrations, decreased the liver expression of carbohydrate response element binding protein transcription factor (x 0.45) and its target genes, and increased the hepatic activity of the fatty acid β-oxidation system (x 1.15). These effects may be related to the fact that atorvastatin decreased the expression of fructokinase (x 0.6) in livers of fructose-supplemented rats, reducing the metabolic burden on the liver that is imposed by continuous fructose ingestion.

Atorvastatin mediates increases in intralesional BAX and BAK expression in human end-stage abdominal aortic aneurysms

Chronic apoptosis activation may participate in abdominal aortic aneurysm (AAA) expansion. Statin treatment slows AAA progression independent of cholesterol lowering. We hypothesized that Atorvastatin treatment alters apoptosis protein expression and activation in AAAs. Protein was isolated from the central and distal portions of end-stage human AAA tissue obtained during surgical repair from non-statin (NST) and Atorvastatin-treated (AT) patients. Expression was compared using immunoblots. Bcl-2 expression was unchanged but Bak (4-fold, p < 0.013) and Bax (3-fold, p < 0.035) expression was increased in AT (n = 12) versus NST (n = 15) patients. No cytochrome c release or caspase 3 activation was detected and Clusterin, GRP78, and BNIP1 expression was similar in NST and AT samples. Bcl-2 and Bax cDNA sequences from AAA tissue (n = 10) and the general population were identical. Thus, the increase in Bax and Bak in AT-treated AAAs did not activate the mitochondria or endoplasmic reticulum mediated apoptosis pathways. Bcl-2, Bax, and Bak have non-apoptosis related functions that include maintenance of endoplasmic reticulum (ER), homeostasis, and adaptation to stress. We speculate that Atorvastatin-mediated increases in Bax and Bak may positively affect their non-apoptosis related cell functions to account for the beneficial effect of statins to slow AAA expansion.

Atorvastatin Modulates Matrix Metalloproteinase Expression, Activity, and Signaling in Abdominal Aortic Aneurysms

Statins may reduce abdominal aortic aneurysm (AAA) progression. We sought to measure how atorvastatin (AT) treatment might modulate matrix metalloproteinase (MMP) expression and/or activity in human AAA. Tissue from human AAAs at surgical repair was obtained from patients who were either not on statins (NST, n = 19) or treated with AT (n = 19). Immunoblots measured expression and zymography measured activity. Expression of most proteins was greater in the central compared with distal AAA region. Matrix metalloproteinase 1, MMP2, MMP3, MMP9, Tissue Inhibitor of Metalloproteinase (TIMP2), TIMP3, TIMP4, or total Sma Mothers Against Decapentaplegia (SMAD2) expression did not differ with treatment. There was a trend toward reduced MMP8 and TIMP1 expression and MMP2 zymographic activity in the AT-treatment group. In contrast, AT-treated samples had significantly reduced MMP13 (P = .02), latent-transforming growth factor (TGF)-β (P = .02), and phospho-SMAD2 (P = .029) expression than NST-treated samples. We conclude that the AT-mediated decrease in MMP expression and activity reduces TGF-β signaling in the central region of human AAAs.

Atorvastatin increases expression of low-density lipoprotein receptor mRNA in human circulating mononuclear cells

1. 3-Hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) inhibitors, or statins, are commonly used to lower plasma cholesterol levels. HMGCR and the low-density lipoprotein (LDL) receptor (LDLR) are of central importance to cholesterol homeostasis and yet there is a paucity of data on the effect of statins on the regulation of the LDLR and HMGCR in humans. 2. In the present study, we examined the effect of atorvastatin on the expression of HMGCR, LDLR and LDLR-related protein (LRP) mRNA in circulating mononuclear cells. Twelve human volunteers were treated with atorvastatin, 20 mg/day for 4 weeks. 3. Atorvastatin decreased plasma total and LDL-cholesterol by 29% (P < 0.0001) and 41% (P < 0.001), respectively, and increased LDLR mRNA abundance, in absolute terms, by 35% (P < 0.001) and 31% (P < 0.0001) and 37% (P = 0.01) relative to reference GAPDH and beta-actin mRNA, respectively. In contrast, atorvastatin had no significant effect on LRP or HMGCR mRNA levels. 4. The increase in LDLR mRNA in circulating mononuclear cells agrees with the few human studies conducted, as well as with in vitro and animal studies, whereas the unchanged HMGCR mRNA is consistent with the hepatic specificity of atorvastatin. The present study firmly documents an increase in LDLR mRNA levels in response to statin administration in normal humans.

Cholesterol metabolism and expression of its relevant genes in cultured steatotic hepatocytes

OBJECTIVE

To investigate the cholesterol metabolism and mRNA expression of the relevant genes in cholesterol synthesis of the cultured steatotic hepatocytes model.

METHODS

A steatotic model of hepatocytes was constructed by adding palmitic acid to the growing L-02 cells. These cells were collected at day 3 and 6, respectively. Cells with the culture solution without palmitic acid added served as the control. The contents of intracellular triglyceride (TG) and total cholesterol (TC) were detected by the analysis kit. The expression of sterol-regulatory element binding protein-2 (SREBP-2) and its target gene hydroxymethylglutaryl CoA reductase (HMGCR) and low-density lipoprotein receptor (LDLR) were measured by RT-PCR.

RESULTS

Hepatocyte steatosis was observed at day 3 and became more intense at day 6. The contents of intracellular TG and TC were increased and the expression of the SREBP-2, HMGCR and LDLR mRNA were upregulated in a time-dependent manner in the model group. Compared with the control group, the content of intracellular TG was higher at both day 3 and 6 (P < 0.05), while the content of intracellular TC was significantly increased only at day 6; The expression of HMGCR and LDLR mRNA was upregulated in steatotic hepatocytes at both day 3 and 6 (P < 0.05), whereas the SREBP-2 mRNA was increased only at day 6 (P < 0.05).

CONCLUSION

Cholesterol accumulation is probably due to the upregulated expression of the relevant genes in the cholesterol synthesis of the steatotic hepatocytes.