Latest medical literature on accupril

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Medical research on accupril

Determination of quinapril and quinaprilat in human plasma by ultraperformance liquid chromatography-electrospray ionization mass spectrometry.

Biomed Chromatogr. 2008 Nov 17;
Dasandi B, Shah S,
A novel, specific and sensitive ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was developed for the simultaneous determination of quinapril and its active metabolite quinaprilat in human plasma. The method involves a simple, one-step extraction procedure coupled with an Acquity UPLCtrade mark BEH C(18 )column (100 x 2.1 mm, i.d., 1.7 microm) with isocratic elution at a flow-rate of 0.2 mL/min and lisinopril as the internal standard. Detection was performed on a triple-quadrupole tandem mass spectrometer in multiple reaction monitoring mode via electrospray ionization. Using 250 microL plasma, the methods were validated over the concentration range 5.010-500.374 ng/mL for quinapril and 10.012-1000 ng/mL for quinaprilat, with a lower limit of quantification of 5.010 ng/mL for quinapril and 10.012 ng/mL for quinaprilat. The intra- and inter-day precision and accuracy were within 10.0%. The recovery was 85.8, 62.6 and 61.3% for quinapril, quinaprilat and lisinopril, respectively. Total run time was 3.0 min only. Copyright (c) 2008 John Wiley & Sons, Ltd.

Effect of angiotensin-converting enzyme inhibition and angiotensin II type 1 receptor blockade on streptozotocin-induced diabetic nephropathy.

Ren Fail. 2008; 30(10): 1023-33
Saniye S, Mehmet K, Sedat U, Cevat A, Dogutan H, Omer Y
The aim of this study was designed to investigate the possible beneficial effects of the angiotensin-converting enzyme (ACE) inhibitor, Quinapril (Q) and, the angiotensin (ang) II T(1) (AT1) receptor blocker, irbesartan (Irb), in streptozotocin (STZ)-induced diabetes in rats. The rats were randomly allotted into one of five experimental groups: A (control), B (diabetic untreated), C (diabetic treated with Q), D (diabetic treated with Irb), and E (diabetic treated with Q&Irb), each group containing 10 animals. Groups B-E received STZ. Diabetes was induced in four groups by a single intraperitoneal (i.p) injection of STZ (50 mg/kg, freshly dissolved in 5 mmol/L citrate buffer, pH 4.5). Two days after STZ treatment, development of diabetes in four experimental groups was confirmed by measuring blood glucose levels in a tail vein blood samples. Rats with blood glucose levels of 250 mg/dL or higher were considered to be diabetic. The rats in Q-, Irb-, and Q&Irb-treated groups were given Q (in a dose of 3 mg/kg body weight), Irb (5 mg/kg body weight), and Q&Irb (in a dose of 1.5 mg/kg + 2.5 mg/kg body weight) once a day orally by using intra-gastric intubation for 12 weeks starting two days after STZ injection. Treatment of Q and especially Irb reduced the glomerular size and thickening of capsular, glomerular, and tubular basement membranes; and increased amounts of mesangial matrix and tubular dilatation and renal function as compared with diabetics untreated. Notably, the better effects were obtained when Q and Irb given together. We conclude that Q, Irb, and especially Q+Irb therapy causes renal morphologic and functional improvement after STZ-induced diabetes in rats. We believe that further preclinical research into the utility of Q and Irb treatment, alone or its combination, may indicate its usefulness as a potential treatment in diabetic nephropathy (DNp).

ADMA impairs nitric oxide-mediated arteriolar function due to increased superoxide production by angiotensin II-NAD(P)H oxidase pathway.

Hypertension. 2008 Nov; 52(5): 960-6
Veresh Z, Racz A, Lotz G, Koller A
Asymmetrical dimethylarginine (ADMA) is thought to be an endogenous regulator of arteriolar tone by inhibiting NO synthase. However, our previous studies showed that, in isolated arterioles, ADMA induced superoxide production as well. Thus, the mechanisms by which ADMA affects arteriolar tone remain obscure. We hypothesized that ADMA, by activating NAD(P)H oxidase, increases superoxide production, interfering with NO mediation of flow-induced dilation. In the presence of indomethacin, isolated arterioles from rat gracilis muscle ( approximately 160 microm at 80 mm Hg) were incubated with ADMA (10(-4) mol/L), which elicited significant constriction (from 162+/-4 to 143+/-4 microm) and eliminated the dilations to increases in intraluminal flow (from a maximum 31+/-2% to 3+/-1%; P

Blood pressure control with amlodipine add-on therapy in patients with hypertension and diabetes: results of the amlodipine diabetic hypertension efficacy response evaluation trial.

Ann Pharmacother. 2008 Nov; 42(11): 1552-62
Kloner RA, Neutel J, Roth EM, Weiss R, Weinberger MH, Thakker KM, Schwartz B, Shi H, Gregg AM,
BACKGROUND: Attainment of blood pressure (BP) goals in patients with diabetes is critical both to reduce the risk of cardiovascular events and to delay the progression of renal disease. While therapeutic guidelines advise initial therapy with an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker, monotherapy with these agents may not be sufficient to attain target BP. OBJECTIVE: The ADHT (Amlodipine Diabetic Hypertension Efficacy Response Evaluation Trial) evaluated the efficacy and safety of adding amlodipine to the treatment regimen of patients with hypertension and diabetes who were already receiving either quinapril or losartan as monotherapy. METHODS: ADHT was a double-blind, double-dummy, 22-week trial conducted in the US. After a washout period of 7-13 days, patients (aged 30-75 y) with hypertension and diabetes were randomized to receive quinapril 20 mg/day plus placebo or losartan 50 mg/day plus placebo for 4 weeks, titrated to 40 mg or 100 mg (if required), respectively, for an additional 4 weeks to achieve their BP goals (

Simultaneous determination of hydrochlorothiazide, quinapril and quinaprilat in human plasma by liquid chromatography-tandem mass spectrometry.

J Chromatogr B Analyt Technol Biomed Life Sci. 2008 Sep 15; 873(1): 59-69
Parekh SA, Pudage A, Joshi SS, Vaidya VV, Gomes NA, Kamat SS
A rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the simultaneous estimation of hydrochlorothiazide, quinapril and its metabolite quinaprilat in human plasma. After solid phase extraction (SPE), the analytes and IS were chromatographed on a hypurity C8 (100 mm x 2.1 mm i.d., 5 microm particle size) column using 2 microL injection volume with a run time of 2.8 min. An isocratic mobile phase consisting of 0.5% (v/v) formic acid:acetonitrile (25:75, v/v) was used to separate all these drugs. The precursor and product ions of these drugs were monitored on a triple quadrupole mass spectrometer, operating in the multiple reaction monitoring mode (MRM) without polarity switch. The proposed method was validated over the range of 5-500 ng/mL for hydrochlorothiazide method and 5-1500 ng/mL for quinapril and quinaprilat. Inter-batch and intra-batch precision (coefficient of variation - % CV) across five validation runs lower limit of quantitation (LLOQ), lower quality control (LQC), middle quality control (MQC), higher quality control (HQC) and upper limit of quantitation (ULOQ) was less than 15. The accuracy determined at these levels was within +/-13% in terms of relative percentage error.

Transport of angiotensin-converting enzyme inhibitors by H+/peptide transporters revisited.

J Pharmacol Exp Ther. 2008 Nov; 327(2): 432-41
Knütter I, Wollesky C, Kottra G, Hahn MG, Fischer W, Zebisch K, Neubert RH, Daniel H, Brandsch M
Angiotensin-converting enzyme (ACE) inhibitors are often regarded as substrates for the H+/peptide transporters (PEPT)1 and PEPT2. Even though the conclusions drawn from published data are quite inconsistent, in most review articles PEPT1 is claimed to mediate the intestinal absorption of ACE inhibitors and thus to determine their oral availability. We systematically investigated the interaction of a series of ACE inhibitors with PEPT1 and PEPT2. First, we studied the effect of 14 ACE inhibitors including new drugs on the uptake of the dipeptide [14C]glycylsarcosine into human intestinal Caco-2 cells constitutively expressing PEPT1 and rat renal SKPT cells expressing PEPT2. In a second approach, the interaction of ACE inhibitors with heterologously expressed human PEPT1 and PEPT2 was determined. In both assay systems, zofenopril and fosinopril were found to have very high affinity for binding to peptide transporters. Medium to low affinity for transporter interaction was found for benazepril, quinapril, trandolapril, spirapril, cilazapril, ramipril, moexipril, quinaprilat, and perindopril. For enalapril, lisinopril, and captopril, very weak affinity or lack of interaction was found. Transport currents of PEPT1 and PEPT2 expressed in Xenopus laevis oocytes were recorded by the two-electrode voltage-clamp technique. Statistically significant, but very low currents were only observed for lisinopril, enalapril, quinapril, and benazepril at PEPT1 and for spirapril at PEPT2. For the other ACE inhibitors, electrogenic transport activity was extremely low or not measurable at all. The present results suggest that peptide transporters do not control intestinal absorption and renal reabsorption of ACE inhibitors.

Pharmacokinetics and bioequivalence study of the two 20-mg quinapril hydrochloride tablet formulations in healthy Thai male volunteers.

J Med Assoc Thai. 2008 May; 91(5): 739-46
Rojanasthien N, Nasangiam N, Kumsorn B, Roongapinun S, Jengjareon A
OBJECTIVE: To determine the pharmacokinetics and bioequivalence of two 20-mg quinapril hydrochloride tablet preparations; Quinaril (The Biolab Ltd, Bangkok, Thailand) as the test and Accupril as the reference. MATERIAL AND METHOD: The present study was a single dose, randomized two-period crossover design conducted in 24 healthy volunteers under fasting conditions with a 7-day washout period. Serial plasma concentrations of quinapril and its active metabolite quinaprilat up to 24 h after dosing were determined by HPLC with UV detection. The pharmacokinetic parameters were analyzed by noncompartmental analysis and the ANOVA was carried out using logarithmically transformed data of the AUC and C as well as untransformed T(max). RESULTS: There were no significant differences between the two preparations regarding the T(max) of quinapril and quinaprilat and their median T(max) were 0.5 h and 1.4 - 1.5 h, respectively. The half-life of quinapril (1.2 h) was faster than quinaprilat (1.8-1.9 h) although the volume of distribution (Vd/F) of quinapril (1.1 L/kg) was larger than quinaprilat (0.3 L/kg), however, its clearance rate (CL/F) was faster when compared to quinaprilat (20-26 ml/min/kg vs. 1.7 ml/min/kg). The mean (90% CI) for the ratios Reference/Test of quinapril were 0.99 (0.89-1.10), 0.99 (0.90-1.09) and 1.01 (0.90-1.14), respectively for AUC(0-24), AUC(0-infinity) and C(max). Similarly, the corresponding values for quinaprilat were 0.95 (0.90-1.01), 0.95 (0.90-1.01) and 1.03 (1.00-1.07), respectively. These values were within the bioequivalence range of 0.80 - 1.25, thus, demonstrated the bioequivalence of the two preparations. CONCLUSION: The results of the present study indicated that the two quinapril HCL preparations are bioequivalent and it can be assumed that they are therapeutically equivalent and exchangeable in clinical practice.

Comparison of the effects of quinapril and irbesartan on P-wave dispersion in hypertensive patients.

Adv Ther. 2008 Aug; 25(8): 775-86
Guntekin U, Gunes Y, Tuncer M, Simsek H, Gunes A
INTRODUCTION: P-wave dispersion (PWD) has been shown to be a non-invasive electrocardiographic predictor for development of atrial fibrillation (AF). Thus, it may be possible to attenuate AF risk through improvement of PWD. In this study, we compared the effects of an angiotensin-converting enzyme (ACE) inhibitor, quinapril, and an angiotensin receptor blocker (ARB), irbesartan, on PWD. METHODS: A total of 38 newly diagnosed hypertensive patients were enrolled in the study. The patients were randomly assigned to receive treatment with either irbesartan (150-300 mg) or quinapril (20-40 mg). P-wave durations and PWD were measured at baseline and after 6 and 12 months of treatment. Echocardiographic examinations were performed at baseline and after 12 months of treatment. RESULTS: Both drugs significantly reduced blood pressure to a similar degree (P

Electrochemical behavior of quinapril and its determination in pharmaceutical formulations by square-wave voltammetry at a mercury electrode.

Pharmazie. 2008 Jun; 63(6): 428-33
Süslü I, Altinöz S
The electrochemical behavior of the antihypertensive drug quinapril was investigated at a hanging mercury drop electrode using different voltammetric techniques such as cyclic voltammetry, square-wave voltammetry and chronoamperometry. A simple and sensitive square-wave voltammetric method for the electrochemical analysis of quinapril in its pharmaceutical formulations was developed and validated. The experimental and instrumental parameters affecting the peak current of quinapril were investigated. Various buffers such as Britton Robinson, borate and phosphate buffers at different pH values (3.0-11.0) were examined as supporting electrolyte. The optimum conditions were obtained using Britton Robinson buffer at pH 10.0 and frequency: 50 Hz, scan increment: 4 mV and pulse amplitude: 25 mV. A well-defined peak current was observed at the hanging mercury drop electrode at -1100 mV vs. Ag/AgCl reference electrode. This proposed method was validated by evaluating linearity, sensitivity, repeatability, accuracy, precision, selectivity, recovery, robustness and ruggedness. The linear calibration range was 0.50-8.68 microg mL-' (r = 0.9992). The detection and quantification limits of this method were 0.22 and 0.50 Ctg mL(-1) and intra-day and inter-day precision were between 0.81-4.32% (n = 7), respectively. The developed method was applied successfully for the determination of quinapril in its tablet dosage forms. The average amount of quinapril in tablets was found as 20.26 +/- 0.12 with RSD of 1.60% for 20 mg tabletsand 40.55 +/- 0.23 with RSD of 1.52% for 40 mg tablets.

Quinapril improves endothelial function in postmenopausal hypertensive patients.

Kidney Blood Press Res. 2008; 31(4): 226-33
Farkas K, Fábián E, Nagy L
BACKGROUND/AIM: Hypertension is one of the main cardiovascular risk factors, and it may be responsible for the excess morbidity and mortality in postmenopausal women. Endothelium-dependent dilation of conduit arteries is reduced in women after menopause, as shown by the reduced flow-mediated dilation (FMD) of the brachial artery. The aim of this study was to evaluate changes in FMD during and following a 6-month-long treatment with increasing doses (10, 20 and 40 mg) of quinapril in hypertensive postmenopausal patients. METHODS: A multicenter, open-label, non-comparative, baseline control study in 61 postmenopausal outpatients. RESULTS: The mean baseline FMD (% +/- SD) of the 53 patients in the intent-to-treat population (patients with at least one FMD evaluation) was 2.83 +/- 1.24%; FMD of the 51 subjects on 10 mg quinapril daily was 5.58 +/- 2.179%; FMD of the 52 patients on 20 mg quinapril was 7.06 +/- 2.31%, and FMD of the 53 subjects on 40 mg daily was 8.07 +/- 2.57% (p < 0.001 for each dose, compared to baseline). CONCLUSION: Ourresults confirmed that quinapril improves endothelial function at all examined doses as measured by FMD. Modulation of the renin-angiotensin system may act as a target for reducing cardiovascular risk in postmenopausal hypertensive women.