Latest medical literature on corgard

Our library of drug research abstracts drawn from the medical literature is updated on a regular schedule, and you can be assured that new corgard research articles will be listed here shortly after becoming available to us.

Medical research on corgard

CGP12177-induced haemodynamic and vascular effects in normotensive and hypertensive rats.

Eur J Pharmacol. 2008 Jun 19;
Holopherne D, Mallem MY, Le Strat E, de Chantemèle EB, Gogny M, Henrion D, Noireaud J, Desfontis JC
CGP12177 is a non-conventional partial agonist, known to have cardiostimulating and vasorelaxant properties related to its agonist action on the low affinity state of the beta(1)-adrenoceptor (beta(1LA)-adrenoceptor). In normotensive Wistar Kyoto (WKY) rats and spontaneously hypertensive rats (SHR), CGP12177-induced vasorelaxant effects were analysed in hindquarter vessels to assess modifications in hind limb vascular resistance, and in femoral artery rings. The global haemodynamic effects induced by CGP12177 were also investigated using telemetry in conscious animals. In hindquarters vasculature precontracted with 5-hydroxytryptamine, CGP12177 (0.16 to 475 mug) produced a similar dose-dependent decrease in hindquarters perfusion pressure in both strains. Vasorelaxation was not modified by nadolol, a beta(1) and beta(2)-adrenoreceptor antagonist, nor by L748337, a beta(3)-adrenoceptor antagonist, but was concentration dependently inhibited by bupranolol, a beta(1LA)-adrenoceptor antagonist at high concentrations. In femoral artery rings from WKY rats and SHR, CGP12177 produced a concentration-dependent relaxation, which was unaffected by nitric oxide synthases inhibition but was significantly reduced in the presence of bupranolol. With double cardiac autonomic blockade (atropine plus atenolol) in conscious WKY rats and SHR, CGP12177 greatly increased heart rate with minor changes in mean arterial pressure in both strains. Conversely, in the absence of double cardiac autonomic blockade, the amplitude of CGP12177-induced heart rate increase was less pronounced and had an hypotensive effect. The reduction in tachycardia and the hypotension were significantly greater in SHR compared to WKY rats. In conclusion, in both strains, CGP12177 produced vasodilating effects in hindquarter vessels and femoral arteries that can be attributed to a beta(1LA)-adrenoceptor stimulation. In conscious WKY rats and SHR, CGP12177-induced cardiostimulation and hypotension were not significantly different after baroreflex blockade, but were decreased and increased respectively, in the presence of baroreflex activity.

Purple-red papules on foot.

J Fam Pract. 2008 Jun; 57(6): 389-91
Welsh JP, Allen HB
An 88-year-old Caucasian man of Italian ancestry came into our clinic with multiple, painful purple-red "growths" on his left foot that he'd had for several years. The patient had no systemic complaints (no fever, chills, weight loss, night sweats). He had a history of hypertension, a cardiac valve replacement, and chronic back pain (secondary to a motor vehicle accident). He was taking warfarin and nadolol. The patient had multiple, 0.1- to 0.5-cm purple-red papules and nodules on the dorsal and plantar surfaces of the left foot, with associated moderate lower extremity edema and mottled dyspigmentation. We did a punch biopsy, which showed a nodular neoplasm composed of moderately plump, spindle-shaped cells in short interweaving fascicles and numerous extravasated erythrocytes in the spaces ("vascular slits") between the spindle-shaped cells. What is your diagnosis, and how would you manage this condition?

Role of central beta-adrenergic receptors in regulating proinflammatory cytokine responses to a peripheral bacterial challenge.

Brain Behav Immun. 2008 May 9;
Johnson JD, Cortez V, Kennedy SL, Foley TE, Hanson H, Fleshner M
Elevation of proinflammatory cytokines in the brain have potent effects on altering physiological, behavioral, and cognitive processes. The mechanism(s) by which brain cytokines are induced during a peripheral immune challenge remains unclear since microorganisms/cytokines do not cross the blood-brain barrier (BBB). Recent studies indicate that central beta-adrenergic receptors (beta-ADRs) may mediate brain interleukin-1beta (IL-1) production. This has direct implications for the production of brain cytokines during a peripheral immune response since peripheral pathogens and cytokines rapidly stimulate brainstem catecholamine neurons via peripheral nerves and circumventricular pathways. Studies here examine the role of central beta-ADRs in regulating brain cytokine production following peripheral Escherichia coli (E. coli) challenge. Rats were centrally administered propranolol (beta-ADR antagonist) or vehicle followed by peripheral E. coli or saline and sacrificed 6h later for measurement of cytokines. Pre-treatment with propranolol completely blocked the induction of brain IL-1 following E. coli. Surprisingly, central propranolol also attenuated E. coli-induced peripheral cytokines. To examine whether the attenuated peripheral cytokine response following central propranolol administration was due leakage of propranolol into the general circulation and blockade of peripheral beta-blockade, nadolol (beta-ADR antagonist that does not cross the BBB) was administered peripherally prior to E. coli. Nadolol administration did not block central cytokine production following E. coli, but instead enhanced both peripheral and central proinflammatory cytokine production. Furthermore, central administration of isoproterenol (beta-ADR agonist) results in a time-dependent increase in brain IL-1 production. These data demonstrate central beta-ADRs may play a critical role to induce brain IL-1, while peripheral beta-ADRs inhibit cytokine response to bacterial challenge.

Primary prophylaxis of esophageal variceal bleeding in cirrhosis.

Gastroenterol Clin Biol. 2008 May; 32(5 Pt 1): 532-40
Bellot P, García-Pagán JC, Abraldes JG, Bosch J
Variceal bleeding is a common and severe complication of liver cirrhosis. The risk of bleeding increases with the size of varices, red wheal marks and disease severity. Noninvasive tests are not accurate enough for the diagnosis of varices, so all patients with cirrhosis should be screened by endoscopy. Nonselective beta-blockers (propranolol, nadolol) are indicated for primary prophylaxis in patients with medium/large varices, and for those with small varices and red signs or advanced liver failure (Child C). In such patients, beta-blockers have been shown to reduce the risk of bleeding from 25 to 15%. There is no evidence to support using beta-blockers with nitrates or spironolactone. In patients with contraindication or intolerance to beta-blockers, endoscopic band ligations are indicated.

Liquid chromatography tandem mass spectrometry assay for the simultaneous determination of venlafaxine and O-desmethylvenlafaxine in human plasma and its application to a bioequivalence study.

J Pharm Biomed Anal. 2008 Jul 15; 47(3): 603-11
Patel BN, Sharma N, Sanyal M, Shrivastav PS
A rapid, simple and sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) assay for simultaneous determination of venlafaxine (VEN) and its active metabolite, O-desmethylvenlafaxine (ODV) in human plasma was developed using nadolol as internal standard (IS). The analytes and IS were extracted from 200mul aliquots of human plasma via protein precipitation using 0.43% formic acid in acetonitrile and separated on a Hypurity cyano (50mmx4.6mm, 5mum) column. Quantitation was performed on a triple quadrupole mass spectrometer employing electrospray ionization technique, operating in multiple reaction monitoring (MRM) and positive ion mode. The precursor to product ion transitions monitored for VEN, ODV and IS were m/z 278.3-->58.1, 264.3-->58.1 and 310.4-->254.1, respectively. The total chromatographic runtime was 3min with retention time for VEN, ODV and IS at 1.93, 1.50 and 1.29min, respectively. The method was fully validated for its sensitivity, accuracy and precision, linearity, recovery, matrix effect, dilution integrity and stability studies. The linear dynamic range of 2.0-500ng/ml was established for both VEN and ODV with mean correlation coefficient (r), 0.9994 and 0.9990, respectively. The intra-batch and inter-batch precision (%CV) in three validation batches across five concentration levels (LLOQ, LQC, MQC, HQC and ULOQ) was less than 12.6% for both the analytes. The accuracy determined at these levels was within -9.8 to +3.9% in terms of %bias. The method was successfully applied to a bioequivalence study of 150mg venlafaxine extended release capsule formulation in 22 healthy Indian male subjects under fed condition.

Pulmonary vein isolation and the Cox maze procedure only partially denervate the atrium.

J Thorac Cardiovasc Surg. 2008 Apr; 135(4): 894-900
Lall SC, Foyil KV, Sakamoto S, Voeller RK, Boineau JP, Damiano RJ, Schuessler RB
OBJECTIVES: The effects of ablation lines on myocardial innervation and response to autonomic stimuli are unclear. This study examined the effects of radiofrequency ablation on atrial autonomic innervation and compared pulmonary vein isolation and the biatrial Cox maze procedure. METHODS: In 12 acute canines right and left vagosympathetic trunks and right and left stellate ganglia were isolated. Each nerve was stimulated before bipolar ablation, after pulmonary vein isolation, and after the Cox maze procedure. Nadolol (n = 6) and atropine (n = 6) were administered to block sympathetic and parasympathetic responses, respectively. Changes in heart rate and atrioventricular interval were compared. Changes in QRST area relative to an isoelectric baseline (index of local innervation) were calculated. RESULTS: Sympathetic stimulation of each nerve and parasympathetic stimulation of the vagosympathetic trunks caused significant changes in heart rate and atrioventricular interval. After pulmonary vein isolation, the effect of 33% of the nerves on heart rate changes was eliminated. The Cox maze procedure eliminated right stellate sympathetic effects on heart rate. Fifty percent of the nerves caused heart rate changes after the Cox maze procedure. There was no significant effect of either lesion set on atrioventricular interval changes. Stimulation of 50% of nerves after pulmonary vein isolation produced local area changes significantly different from control area. After the Cox maze procedure, a different 50% of the nerves produced local changes different from those seen after pulmonary vein isolation. CONCLUSIONS: Surgical ablation procedures disrupted innervation, affecting heart rate but not atrioventricular interval. Autonomic innervation affecting the atria was changed by pulmonary vein isolation and additionally by the Cox maze procedure. Residual autonomic effects were present even after the complete Cox maze procedure.

Say what, beta-blockers for asthma?

Am J Respir Cell Mol Biol. 2008 Mar; 38(3): 249-50
Chupp GL

Treatment of gastropathy and gastric antral vascular ectasia in patients with portal hypertension.

Curr Treat Options Gastroenterol. 2007 Dec; 10(6): 483-94
Ripoll C, Garcia-Tsao G
Portal hypertensive gastropathy (PHG) and gastric antral vascular ectasia (GAVE) are two distinct gastric mucosal lesions that may cause acute and/or chronic upper gastrointestinal hemorrhage in patients with cirrhosis. Whereas PHG is associated with portal hypertension, GAVE may present in patients without portal hypertension or liver disease. Diagnosis is made upon visualization of the characteristic lesions with upper gastrointestinal endoscopy, although the differential may be difficult at times. PHG is characterized endoscopically by a mosaic pattern with or without red signs and a proximal distribution. PHG mainly causes chronic blood loss and anemia in patients with cirrhosis but also can cause acute hemorrhage. First-line therapy for chronic hemorrhage from PHG is a nonselective beta-blocker (propranolol or nadolol) and iron supplementation. If bleeding/anemia are not controlled with these measures and the patient is transfusion-dependent, shunt therapy (transjugular intrahepatic portosystemic shunt or shunt surgery) should be considered. Management of acute bleeding from PHG, an infrequent event, should be accomplished with a vasoactive drug, somatostatin (or its analogues) or terlipressin. If bleeding responds, the patient must be switched to a nonselective beta-blocker. Shunt therapy should be considered in patients who rebleed or continue to bleed despite adequate beta-blocker therapy. GAVE is less common than PHG. It is characterized by red spots without a background mosaic pattern, typically in the gastric antrum. When lesions have a linear distribution, the lesion is called "watermelon stomach." GAVE is a cause of chronic gastrointestinal bleeding and anemia in patients with cirrhosis. If lesions are localized, first-line therapy is argon plasma coagulation. In more diffuse lesions, therapy with argon plasma coagulation is more complicated. Preliminary data suggest that cryotherapy may be a reasonable option for diffuse GAVE lesions. Neither beta-blockers nor TIPS reduces the bleeding risk in patients with GAVE and thus should not be used in this setting.

Beta3-adrenoceptors modulate left ventricular relaxation in the rat heart via the NO-cGMP-PKG pathway.

Acta Physiol (Oxf). 2008 Jul; 193(3): 229-39
Angelone T, Filice E, Quintieri AM, Imbrogno S, Recchia A, Pulerà E, Mannarino C, Pellegrino D, Cerra MC
AIMS: Using a model of isolated and Langendorff-perfused rat heart we analysed whether activation of beta3-adrenergic receptors (beta3-ARs) influences ventricular lusitropic performance. We also focused on the NOS/NO/cGMP/PKG cascade as the signal transduction mechanism. METHODS: Hearts were treated with increasing concentrations (from 10(-12) to 10(-6) m) of BRL(37344), a selective beta3-AR agonist, and cardiac performance was evaluated by analysing both lusitropic parameters and coronary motility. Cardiac preparations were also perfused with BRL(37344) in the presence of either isoproterenol (ISO) or nadolol, or pertussis toxin (PTx), or selective inhibitors of the NOS/NO/cGMP/PKG pathway. RESULTS: BRL(37344) caused a significant concentration-dependent reduction in (LVdP/dt)(min), a decrease in half time relaxation significant starting from 10(-12) m, and an increase in (LVdP/dt)(max)/(LVdP/dt)(min) ratio (T/-t). BRL(37344) abolished the ISO-mediated positive lusitropism. beta3-AR-dependent effects on relaxation were insensitive to beta(1)/beta2-AR inhibition by nadolol (100 nm), and were abolished by G(i/o) protein inhibition by PTx (0.01 nm). NO scavenging by haemoglobin (10 microm), and nitric oxide synthase (NOS) inhibition by NG-monomethyl-l-arginine (10 microm) revealed the involvement of NO signalling in BRL(37344) response. Pre-treatment with inhibitors of either soluble guanylate cyclase (ODQ; 10 microm) or PKG (KT(5823); 100 nm) abolished beta3-AR-dependent negative lusitropism. In contrast, anantin (10 nm), an inhibitor of particulate guanylate cyclase, did not modify the effect of BRL(37344) on relaxation. CONCLUSION: Taken together, our findings provide functional evidence for beta3-AR modulation of ventricular relaxation in the rat heart which involves PTx-sensitive inhibitory Gi protein and occurs via an NO-cGMP-PKG cascade. Whether the effects of beta3-AR stimulation on lusitropism are beneficial or detrimental remains to be established.

Effect of chronic beta-blockade on QT interval in patients with liver cirrhosis.

J Hepatol. 2008 Mar; 48(3): 415-21
Zambruni A, Trevisani F, Di Micoli A, Savelli F, Berzigotti A, Bracci E, Caraceni P, Domenicali M, Felline P, Zoli M, Bernardi M
BACKGROUND/AIMS: QT interval prolongation is frequent in cirrhosis, predicts a poor prognosis and may trigger severe ventricular arrhythmias. Our aim was to evaluate the effect of chronic beta-blockade on QT prolongation. METHODS: Clinical and laboratory evaluation, ECG and hepatic vein pressure gradient (HVPG) measurement were performed in 30 cirrhotic patients before and 1-3 months after prophylactic nadolol. QT was corrected for heart rate by the cirrhosis-specific formula and other formulas. RESULTS: QT(cirrhosis) was prolonged in 10 patients (33%); HVPG was increased in all cases. QT(cirrhosis) was correlated with the Child-Pugh score (r=0.40; p=0.027). Nadolol shortened QT interval only with the Bazett formula (p=0.01), remaining unchanged with the other formulas. The QT interval shortened only if prolonged at baseline (from 473.3+/-5.5 to 458.4+/-6.5 ms; p=0.007), while it lengthened when normal (from 429.8+/-3.1 to 439.3+/-2.9 ms; p=0.01). QTc changes were directly related to the baseline value (p