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Recenti Prog Med. 2008 Sep; 99(9): 443-50
Ipponi A, Moriconi S, Pelagotti F, Lombardo G, Pagni M, Colombai R, Donati MG, Banfi R, Roccato E
Dispensing medication at the discharge of patients is an activity that allows to the Pharmacy Department to have a privileged point of view about prescribing new drugs and therapies. During last year we met several prescriptions for new drugs utilized in the treatment of pulmonary arterial hypertension (PAH), These prescriptions are the mirror of the avalaibility of new specific drugs. PAH is a rare and fatal disease; current disease-specific therapeutic interventions in PAH established pathways in disease treatment: prostacyclin, endothelin receptors antagonist. Several studies indicate that sildenafil, an oral phosphodiesterase type-5 inhibitor, may also offer benefits in the pharmacological management of PAH as well as tadalafil or vardenafil too. We collected data from our Pharmacy patient's database to evaluate the impact of this rare disease on our setting, to analyse the patterns of prescription of our physicians and to think specific health policy or pathways for the patients suffering from this disease.
J Chromatogr B Analyt Technol Biomed Life Sci. 2008 Nov 14;
Ku HY, Shon JH, Liu KH, Shin JG, Bae SK
A rapid and sensitive LC-MS/MS method for the determination of vardenafil and its major metabolite, N-desethylvardenafil, in human plasma using sildenafil as an internal standard was developed and validated. The analytes were extracted from 0.25-mL aliquots of human plasma by liquid-liquid extraction, using 1mL of ethyl acetate. Chromatographic separation was carried on a Luna C(18) column (50mmx2.0mm, 3mum) at 40 degrees C, with an isocratic mobile phase consisting of 10mM ammonium acetate (pH 5.0) and acetonitrile (10:90, v/v), a flow rate of 0.2mL/min, and a total run time of 2min. Detection and quantification were performed using a mass spectrometer in the selected reaction-monitoring mode with positive electrospray ionization at m/z 489.1-->151.2 for vardenafil, m/z 460.9-->151.2 for N-desethylvardenafil, and m/z 475.3-->100.1 for the internal standard (IS), respectively. This assay was linear over a concentration range of 0.5-200ng/mL with a lower limit of quantification of 0.5ng/mL for both vardenafil and N-desethylvardenafil. The coefficient of variation for the assay precision was 93.1%. This method was successfully applied to a pharmacokinetic study after oral administration of vardenafil 20mg tablet in Korean healthy male volunteers.
J Sex Med. 2008 Nov 17;
Uckert S, Bazrafshan S, Sonnenberg JE, Kuczyk ME
ABSTRACT Introduction. It has been suggested that the capability of the phosphodiesterase 5 (PDE5) inhibitor sildenafil citrate (VIAGRA) to retard the ejaculatory response may include modulation of the contraction of seminal vesicle (SV) smooth muscle. In fact, it has been shown that PDE inhibitors can reverse the tension of isolated human SV tissue and enhance the production of cyclic AMP and cyclic GMP. Aim. The aim of this study was to examine the effects of selective phosphodiesterase (PDE) inhibitors on both the spontaneous and electrically induced phasic contractions of isolated human SV smooth muscle. Main Outcome Measures. To measure the inhibition exerted by PDE inhibitors vinpocetine (PDE1-inhibitor), rolipram (PDE4-inhibitor), sildenafil, and vardenafil (PDE5-inhibitors) on the phasic contractile response of isolated SV tissue. Methods. Using the organ bath technique, the effects of increasing concentrations of the PDE inhibitors (1 nM-10 microM) were investigated on phasic contractions of SV tissue strips either mediated by means of electrical field stimulation (EFS) or the alpha(1)-adrenoceptor agonist norepinephrine. Results. The contractile activity in response to EFS was dose-dependently reversed by the PDE inhibitors. The rank order of efficacy was: rolipram > sildenafil >/= vardenafil > vinpocetine. Mean maximum inhibition of contraction was determined as -89.6% (rolipram), -61.3% (sildenafil), -62% (vardenafil), and -46% (vinpocetine). No differences were registered with regard to the effects of sildenafil and vardenafil on the inhibition of the contraction amplitudes. The frequency of the spontaneous contractions (amplitudes/5 minutes) was reduced by 50% in the presence of 2 microM rolipram, 5 microM sildenafil or vardenafil, and 8 microM vinpocetine. Conclusion. Our results demonstrate that PDE inhibitors can inhibit EFS-induced and spontaneous contractile activity of isolated human SV tissue. These findings might be of importance with regard to the pharmacological treatment of premature ejaculation.Uckert S, Bazrafshan S, Sonnenberg JE, and Kuczyk ME. Effects of phosphodiesterase inhibitors on the contractile responses of isolated human seminal vesicle tissue to adrenergic stimulation.
Transplantation. 2008 Nov 27; 86(10): 1414-8
Loganathan S, Radovits T, Hirschberg K, Korkmaz S, Barnucz E, Karck M, Szabó G
Recently, the infarct reducing and cardioprotective effects of phosphodiesterase-5-inhibitors were described. In this study, we investigated these effects on ischemia/reperfusion injury in a rat model of heart transplantation. Three groups were assigned for our study: a vardenafil preconditioning group, an ischemic control, and a nonischemic control. Hemodynamic parameters were significantly increased in the vardenafil group (Pmax: 82+/-4 vs. 110+/-12 vs. 127+/-13 mm Hg; dP/dtmax: 1740+/-116 vs. 3197+/-599 vs. 4397+/-602 mm Hg/sec; ischemic control vs. vardenafil vs. nonischemic control; P
J Chromatogr B Analyt Technol Biomed Life Sci. 2008 Dec 15; 876(2): 283-7
Vos RM, Chahbouni A, Sinjewel A, Swart EL
A simple, sensitive and specific liquid chromatography tandem mass spectrometry method with minimal sample pretreatment was developed for the simultaneous analysis of sildenafil and its metabolite desmethylsildenafil in human serum. Sample pretreatment consisted of adding a methanolic solution of the internal standard vardenafil to the samples. After vortexing and centrifugation the samples were directly injected onto the C18 column using gradient elution. The aqueous and organic mobile phases were ammonium acetate 2mM supplemented with 0.1% formic acid in water and methanol, respectively. The detection by a triple quadrupole mass spectrometer in positive ESI ionization mode was completed within 5min. The lower limits of quantification for sildenafil and desmethylsildenafil are 1.0ng/ml. The intra- and inter-day precisions measured as relative standard deviation were within 10% for both compounds over the linear range. Intra- and inter-day accuracy of sildenafil and desmethylsildenafil ranged from 92 to 103%. This method has been used in a clinical pharmacokinetic study of sildenafil in intensive care patients.
BJU Int. 2008 Nov 13;
Matsumoto S, Hanai T, Uemura H, Levin RM
OBJECTIVES To investigate whether vardenafil, a phosphodiesterase 5 (PDE-5) inhibitor, would protect the bladder from decompensatory changes in a 4-week rat bladder outlet obstruction (BOO) model, as evidence has been accumulating that PDE-5 inhibitors improve lower urinary tract symptoms (LUTS) in patients with benign prostatic hyperplasia (BPH). MATERIALS AND METHODS In all, 50 12-week-old female Sprague-Dawley rats were divided into five equal groups; group 1, sham operated vehicle control rats; group 2, BOO vehicle rats; group 3-5, BOO rats given oral vardenafil at 5, 20, 80 mg/L, respectively. Vardenafil was given in drinking water from the day of surgery. At 4-weeks after the introduction of BOO, vardenafil was washed-out by giving water for 24-48 h, and then the bladder was excised and dissected into four longitudinal strips for isometric organ-bath assay. Contractile responses of bladder strips to electrical field stimulation (EFS), carbachol and KCl was determined for each group. RESULTS BOO induced a significant increase in bladder weight in group 2 compared with group 1. Bladder weights of groups 3-5 were not significantly different from that of group 2. The contractile forces in response to EFS, carbachol and KCl in group 2 were 30.7-51.7% of those in group 1. Vardenafil treatment in groups 3-5 generally did not block the BOO-induced reduction of contractile force in the bladder strips. However, treatment with a high dose of vardenafil resulted in a significant increase in the contractile response to carbachol (78.4% group 5 vs 51.7% group 2). CONCLUSION Chronic treatment with a high dose of vardenafil protected the rat bladder from BOO-induced contractile dysfunction to carbachol.
The role of combination medical therapy in benign prostatic hyperplasia.
Int J Impot Res. 2008 Dec; 20 Suppl 3: S33-43
Greco KA, McVary KT
To review key trials of monotherapy and combination therapy of alpha(1)-adrenergic receptor antagonists (alpha(1)-ARAs), 5alpha-reductase inhibitors (5alphaRIs) and anti-muscarinic agents in the treatment of lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH). To assess the safety and efficacy of combination therapies for LUTS associated with BPH, a search of the MEDLINE and Cochrane databases (1976-2008) was conducted for relevant trials and reviews using the terms benign prostatic hyperplasia, lower urinary tract symptoms, alpha(1)-adrenergic receptor antagonists, 5alpha-reductase inhibitors, anti-muscarinics, anticholinergics, combination therapy, alfuzosin, doxazosin, tamsulosin, terazosin, dutasteride, finasteride, tolterodine, flavoxate, propiverine, oxybutynin, erectile dysfunction, sildenafil, vardenafil and tadalafil. Data from the Medical Therapy of Prostatic Symptoms (MTOPS) study indicated a role for long-term use of alpha(1)-ARAs and 5alphaRIs in combination. In the MTOPS study, combination therapy with the alpha(1)-ARA doxazosin and the 5alphaRI finasteride was significantly more effective than either component alone in reducing symptoms (P=0.006 vs doxazosin monotherapy; P
[Tadalafil for erectile dysfunction: outstanding efficacy for 36 hours]
Zhonghua Nan Ke Xue. 2008 Sep; 14(9): 857-60
Deng SM
Phosphodiesterase type 5 (PDE5) inhibitors are first-line oral medication for erectile dysfunction (ED). Compared with the other two PDE inhibitors (sildenafil and vardenafil), tadalafil is characterized by rapid onset, convenient dosing, excellent efficacy, especially the 36-hour duration of effectiveness deriving from long elimination half-life, allowing for more flexibility to scheduled medication. Higher satisfaction of patients and their partners with tadalafil is mainly due to such psychosocial benefits as decreased time concerns. Tadalafil is well-tolerated, consistent with the principle of safely, effectiveness and convenient dosing and is becoming the favorite choice of ED patients and their partners.
The use of phosphodiesterase 5 inhibitors with concomitant medications.
J Endocrinol Invest. 2008 Sep; 31(9): 799-808
Corona G, Razzoli E, Forti G, Maggi M
The phosphodiesterase-5 inhibitors (PDE5i) sildenafil, vardenafil, and tadalafil are considered first-line therapy for the treatment of patients with erectile dysfunction (ED). In addition to the classical pro-erectile-effect, clinical findings have suggested that they can also influence vascular tone in pulmonary, coronary and other vascular tissues, as well as improving symptoms associated with benign prostatic hyperplasia. Therefore, considering the hypothetical widespread application of PDE5i, the potential for drug-drug interactions emerges as a relevant factor in determining the safety profile of PDE5i. Review of relevant literature was conducted using data sources from MEDLINE (1998, to June 2007). The use of nitrates remains the only contraindication for all 3 PDE5i. Vardenafil is also not recommended in patients taking type 1A (such as quinidine, or procainamide) or type 3 antiarrhythmics (such as sotalol, or amiodarone) while no other major limitations have been reported for tadalafil and sildenafil. In contrast to previously reported labeling, recent studies have suggested only a precaution, but not contraindication with the concomitant use of alpha-blockers agents. In addition, precaution is also suggested in the presence of potent CYP3A inhibitors, such as azole antifungals, antiretroviral protease inhibitors, or macrolid antibiotics. This is because sildenafil, vardenafil, and tadalafil are metabolized mainly via the CYP3A4 pathway. On the other hand, statins and testosterone seem to have synergic effects with PDE5i on sexual activity.
Clin Exp Pharmacol Physiol. 2008 Oct 15;
Toque HA, Priviero FB, Zemse SM, Antunes E, Teixeira CE, Webb RC
1. The anococcygeus muscle is part of the erectile machinery in male rodents. Phosphodiesterase (PDE) 5 inhibitors enhance and prolong the effects of cGMP, which has a key role in penile erection. The aim of the present study was to provide a functional and biochemical comparison of the three PDE5 inhibitors, namely sildenafil, tadalafil and vardenafil, in the rat anococcygeus muscle. 2. Muscle strips were mounted in 4 mL organ baths and isometric force recorded. Levels of cGMP were measured using an enzyme immunoassay kit. Western blots were used to determine PDE5 protein expression. 3. The PDE5 inhibitors concentration-dependently relaxed carbachol-precontracted anococcygeus muscle; however, vardenafil was more potent (pEC(50) = 8.11 +/- 0.05) than sildenafil (7.72 +/- 0.06) or tadalafil (7.69 +/- 0.05). Addition of N(G)-nitro-l-arginine methyl ester (100 micromol/L) or 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (10 micromol/L) to the organ baths caused significant rightward shifts in concentration-response curves for all PDE5 inhibitors. 4. Sildenafil, tadalafil and vardenafil (all at 0.1 micromol/L) caused leftward shifts in the glyceryl trinitrate (GTN) concentration-response curves (by 4.0-, 3.7- and 5.5-fold, respectively). In addition, all three PDE5 inhibitors significantly potentiated relaxation responses to both GTN (0.01-10 micromol/L) and electrical field stimulation (EFS; 1-32 Hz), with vardenafil having more pronounced effects. 5. All three PDE5 inhibitors reduced EFS-evoked contractions in a concentration-dependent manner over the concentration range 0.001-1 micromol/L. There were no significant differences between the effects of the three PDE5 inhibitors. 6. Vardenafil (0.01-0.1 micromol/L) was more potent in preventing cGMP degradation in vitro than sildenafil (0.01-0.1 micromol/L) and tadalafil (0.01-0.1 micromol/L). 7. Under control conditions, the expression of PDE5 was higher in the anococcygeus muscle than in the corpus cavernosum. 8. In conclusion, PDE5 inhibitors enhance exogenous and endogenous nitric oxide-mediated relaxation in the rat anococcygeus muscle. The potency of vardenafil was greater than that of either sildenafil or tadalafil.