AIMTo develop a new synthetic route for olmesartan medoxomil.

METHODSOlmesartan medoxomil was prepared from ethyl 4-(1-hydroxy-1-methylethyl)-2-propylimidazole-5-carboxylate via hydrolysis and lactonization to afford 4,4- dimethyl-2-propyl-4,6-dihydrofuro [3,4-d]-1H-imidazole-6-one which was condensed with 2-(triphenylmethyl)-5-[4'-(bromomethylbiphenyl)-2-yl] tetrazole, followed by esterification with 4-chloromethyl-5-methyl-1,3-dioxol-2-one, and deprotection. The chemical structure of the major impurity in condensation reaction is the regio-isomer in the imidazole moiety, and confirmed by single crystal X-ray diffraction. The corresponding regio-isomer of olmesartan medoxomil was synthesized from the impurity by similar method. Optimization of the condensation conditions reduced the impurity to a negligible quantity.

RESULTSSynthesis of olmesartan medoxomil by the new route gave a product of 60% yield and above 99.0% purity. The content of olmesartan medoxomil regio-isomer was effectively controlled to less than 0.1%.

CONCLUSIONA novel synthetic route for olmesartan medoxomil was developed successfully. The olmesartan medoxomil regio-isomer is reported for the first time.

Angiotensin II Type 1 Receptor Blockers ; chemical synthesis ; chemistry ; Animals ; Antihypertensive Agents ; chemical synthesis ; chemistry ; pharmacology ; Blood Pressure ; drug effects ; Imidazoles ; chemical synthesis ; chemistry ; pharmacology ; Molecular Structure ; Olmesartan Medoxomil ; Rats ; Stereoisomerism ; Tetrazoles ; chemical synthesis ; chemistry ; pharmacology

OBJECTIVETo evaluate the efficacy and safety of olmesartan medoxomil compared with losartan potassium in patients with mild to moderate essential hypertension.

METHODThis is a randomized, double-blind, double-dummy, active-controlled, parallel, multi-center study. After a 2-week placebo run-in period, a total of 287 eligible subjects were randomized at 1:1 ratio to receive olmesartan medoxomil 20 mg or losartan potassium 50 mg, once daily for 8 weeks. The blood pressure was assessed after 4 weeks treatment. If the subject's seating diastolic blood pressure (SeDBP) was still >or=90 mm Hg, the dosage was doubled for another 4 weeks; for those subjects whose SeDBP was <90 mm Hg after 4-week treatment, the initial dosage remained unchanged and the treatment continued until completion of the study.

RESULTS(1) The mean trough reduction in SeDBP from baseline in olmesartan group was significantly greater than that in losartan group after 4 weeks (11.72 mm Hg vs 9.23 mm Hg, P=0.004) and 8 weeks treatment (12.94 mm Hg vs 11.01 mm Hg, P=0.035). (2) The number and percentage of responders in olmesartan group (81, 65.3%) were statistically higher than those (68, 52.7%) in losartan group (P=0.028) after 4 weeks treatment and were similar between the two groups after 8 weeks treatment (P>0.05). (3) Individual and overall trough/peak ratios of DBP and SBP in 24-hour ambulatory blood pressure monitoring were higher in olmesartan group than losartan group. The hypotensive effect of olmesartan was more durable than losartan at 24 hour interval. (4) The incidence of study drug-related adverse events (AEs) in olmesartan group (10.5%) was similar as that in losartan group (13.9%, P>0.05). Most of these AEs were mild and transient.

CONCLUSIONThis study shows that olmesartan medoxomil, at oral dose of 20 mg-40 mg once daily was effective and safe for hypertension treatment and the hypotensive effect was superior to losartan potassium (50 mg-100 mg once daily).

Adolescent ; Adult ; Aged ; Antihypertensive Agents ; administration & dosage ; China ; Double-Blind Method ; Female ; Humans ; Hypertension ; drug therapy ; physiopathology ; Imidazoles ; adverse effects ; therapeutic use ; Losartan ; adverse effects ; therapeutic use ; Male ; Middle Aged ; Olmesartan Medoxomil ; Tetrazoles ; adverse effects ; therapeutic use

BACKGROUND/AIMS: To evaluate the effects of the phosphodiesterase type 5 (PDE5) inhibitor vardenafil on esophageal function, including bolus transit, using multichannel intraluminal impedance and esophageal manometry (MII-EM). METHODS: Sixteen healthy volunteers (15 men) underwent an MII-EM study including 10 liquid swallows and 10 viscous swallows in a seated position after fasting. Then, each subject was asked to ingest 50 mL distilled water or 10 mg vardenafil dissolved in 50 mL water, in a double-blind manner. After 25 minutes, the MII-EM study was repeated. RESULTS: Eight men received vardenafil and eight subjects received water. Resting and residual lower esophageal sphincter pressures differed significantly only in the vardenafil group (from 18 +/- 6.7 to 6.6 +/- 5.3 mmHg, P < 0.001 and from 4.9 +/- 2.6 to 2.1 +/- 3.6 mmHg, P = 0.006, respectively). Mean distal esophageal amplitude decreased significantly only in the vardenafil group (from 86.7 +/- 41.6 to 34.0 +/- 38.0 mmHg, P < 0.05). Complete bolus transits of liquid and viscous meals decreased significantly only after vardenafil ingestion (from 80.2% +/- 13.8% to 49.4% +/- 27.9%, P < 0.05 and from 72.8% +/- 33.6% to 21.5% +/- 29.0%, P = 0.01, respectively). CONCLUSIONS: Vardenafil decreased esophageal bolus transit in the seated position, despite decreased lower esophageal sphincter pressure.
Eating ; Electric Impedance ; Esophageal Sphincter, Lower ; Fasting ; Humans ; Imidazoles ; Male ; Manometry ; Meals ; Piperazines ; Sulfones ; Swallows ; Triazines ; Water ; Vardenafil Dihydrochloride

PURPOSE: To clarify whether vardenafil can be used as a substitute for intracavernosal injection as a method of induction of penile erection, we compared the outcome of penile duplex Doppler ultrasonography using both methods in the same patient with erectile dysfunction. MATERIALS AND METHODS: A total of 23 patients underwent penile duplex ultrasonography twice with a one week interval between procedures. Twelve were randomly selected for intracavernosal injection first with prostaglandin E1(PGE1) 20microgram and the remaining 11 were initially treated with oral vardenafil 20mg 1 hour before the Doppler study and in addition had visual sexual stimulation using a head-mounted display during the study. The peak systolic velocity(PSV), end diastolic velocity(EDV) and the degree of maximum erectile response were measured and compared between the two groups. RESULTS: Measurements from the PGE1 treatment were not significantly different from those with the vardenafil treatment. The percentage of compatibility between the two methods with regard to hemodynamic diagnosis and pharmaceutical erectile response was as high as 83%(19 of 23) and 91%(21 of 23), respectively. Both methods were tolerable and safe without severe complications. However, in 4 patients where the diagnosis was uncertain, the injection method provided a more accurate interpretation of the penile vascular status with duplex ultrasonography. CONCLUSIONS: These results suggest that oral vardenafil can be used as an initial method for inducing penile erection when assessing erectile dysfunction with penile duplex Doppler ultrasonography in selected patients with erectile dysfunction.
Alprostadil ; Erectile Dysfunction ; Hemodynamics ; Humans ; Imidazoles ; Male ; Penile Erection ; Phosphodiesterase Inhibitors ; Piperazines ; Sulfones ; Triazines ; Ultrasonography, Doppler, Duplex ; Vardenafil Dihydrochloride

OBJECTIVETo investigate the neointima formation and the expression of monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-alpha (TNF-alpha) in cuff-induced vascular injury in mouse model, and to examine the effect of angiotensin II type 1 receptor (AT1) blocker, olmesartan, on MCP-1 and TNF-alpha expression and consequently vascular remodeling.

METHODSVascular injury was induced by polyethylene cuff-placement around the mouse femoral artery. Some mice were treated with AT1 receptor blocker, olmesartan, at the dose of 3 mg.kg(-1).day(-1) with an osmotic minipump. Neointima formation and the proliferation of vascular smooth muscle cells (VSMCs) were measured by morphometric analysis and bromodeoxyuridine (BrdU) incorporation. MCP-1 and TNF-alpha expression was detected by Western blot and immunohistochemical staining.

RESULTSWe observed neointima formation 14 days after cuff placement as well as VSMCs proliferation in the media and neointima. Cuff placement also induced MCP-1 and TNF-alpha expression in the media and neointima that the VSMCs specifically existed. Treatment of mice with olmesartan at a dose of 3 mg.kg(-1).day(-1), which did not influence systolic blood pressure, significantly decreased neointima formation and the proliferation of VSMCs. Olmesartan also inhibited MCP-1 and TNF-alpha expression in the injured arteries.

CONCLUSIONSOur results demonstrate that blockade of AT1 receptor inhibits MCP-1 and TNF-alpha expression and thereby improves vascular remodeling.

Analysis of Variance ; Animals ; Blotting, Western ; Cell Division ; drug effects ; physiology ; Cells, Cultured ; Chemokine CCL2 ; analysis ; Disease Models, Animal ; Imidazoles ; pharmacology ; Immunohistochemistry ; Male ; Mice ; Mice, Inbred C57BL ; Monocytes ; cytology ; drug effects ; Muscle, Smooth, Vascular ; cytology ; drug effects ; Neovascularization, Physiologic ; drug effects ; physiology ; Olmesartan Medoxomil ; Probability ; Sensitivity and Specificity ; Tetrazoles ; pharmacology ; Tumor Necrosis Factor-alpha ; analysis ; drug effects ; Tunica Intima ; drug effects ; pathology ; Vascular Diseases ; physiopathology

The remarkable therapeutic success of PDE5 inhibitors in the treatment of male erectile dysfunction has focused the attention of the researchers on better defining the properties of the individual inhibitors and PDE5 that contribute to the high affinity of these inhibitors for interaction with the PDE5 catalytic site. Recent molecular studies have demonstrated that vardenafil has high affinity for PDE5 and low dissociation rate from PDE5, which serves to explain why vardenafil works with low dosage, onsets quickly and has curative action in clinical practice. Moreover, the potency of vardenafil depends on its ring structure that resembles the purine moiety in cGMP.
Drug Interactions ; Erectile Dysfunction ; drug therapy ; Humans ; Imidazoles ; chemistry ; pharmacology ; Male ; Molecular Structure ; Phosphodiesterase Inhibitors ; chemistry ; pharmacology ; Piperazines ; chemistry ; pharmacology ; Sulfones ; chemistry ; pharmacology ; Triazines ; chemistry ; pharmacology ; Vardenafil Dihydrochloride

PURPOSE: Oxytocin is associated with the ability to form normal social attachments. c-Fos is an immediate early gene whose expression is used as a marker for stimulus-induced changes in neurons. The effect of phosphodiesterase-5 (PDE-5) inhibitors on oxytocin activation in the brain without sexual stimuli has not yet been reported. In the present study, we investigated the effects of vardenafil on oxytocin and c-Fos expression in the paraventricular nucleus (PVN) of conscious rats. METHODS: Male Sprague-Dawley rats weighing 300+/-10 g were divided into 6 groups (n=5 in each group): the control group, the 1-day-0.5 mg/kg, the 1-day-1 mg/kg, the 1-day-2 mg/kg, the 3-day-1 mg/kg, and the 7-day-1 mg/kg vardenafil administration group. The experiment was conducted without sexual stimulation. Vardenafil was orally administered. The animals in the control group received an equivalent amount of distilled water orally. The expression of oxytocin and c-Fos in the PVN was detected by immunohistochemistry. RESULTS: Oxytocin expression in the PVN was increased by 1 day administration of 2 mg/kg vardenafil, and this effect of vardenafil appeared in a duration-dependent manner. c-Fos in the oxytocin neurons of the PVN was increased by 1 day administration of 2 mg/kg vardenafil, and this effect of vardenafil also appeared in a duration-dependent manner. These results showed that vardenafil augments the expression of oxytocin with activation of oxytocin neurons in the PVN. CONCLUSIONS: In this study, we showed that the PDE-5 inhibitor, vardenafil directly enhances oxytocin expression and also activates oxytocin neurons in the PVN, which indicates that vardenafil may exert positive effects on affiliation behavior and social interaction.
Animals ; Brain ; Cyclic Nucleotide Phosphodiesterases, Type 5 ; Humans ; Imidazoles ; Interpersonal Relations ; Male ; Neurons ; Oxytocin ; Paraventricular Hypothalamic Nucleus ; Piperazines ; Rats ; Rats, Sprague-Dawley ; Sulfones ; Triazines ; Water ; Vardenafil Dihydrochloride

PURPOSE: After the market launch of multiple phosphodiesterase type 5 inhibitors (PDE5Is), a considerable amount of information has emerged regarding the efficacy and the time of initiation of these drugs. In clinical situations, however, many patients with erectile dysfunction (ED) have complained about the onset of erection occurring later than expected or desired. We therefore studied the time course for initiating an erection after usage of PDE5Is. MATERIALS AND METHODS: One hundred forty-one patients who were medicated with PDE5Is > 4 times in the most recent 3 months were included for study. The patients were divided into 3 groups: sildenafil (n=51), vardenafil (n=51), and tadalafil (n=39). The choice of PDE5I was made according to the patient's and/or doctor's preferences. Regardless of the type of drug selected, the patients were recommended to have sexual stimulation 15 minutes after taking the medication. RESULTS: The onset of action of the 3 drug groups were significantly different (sildenafil, 57.0+/-38.5 min; tadalafil, 79.5+/-50.6 min; and vardenafil, 44.4+/-26.6 min; p<0.05). Psychogenic causes of ED resulted in a shorter PDE5I onset of action than organic causes of ED. Other factors, such as body mass index and international index of erectile function erectile function domain score, were shown not to differ with respect to the onset of action of PED5Is. CONCLUSION: In clinical situations, patients need more time for the onset of erections after taking PDE5Is. For restoration of a healthy sexual life, patients needs more time to achieve an erection after taking PDE5Is.
Body Mass Index ; Carbolines ; Erectile Dysfunction ; Humans ; Imidazoles ; Male ; Phosphodiesterase 5 Inhibitors ; Piperazines ; Purines ; Sulfones ; Triazines ; Sildenafil Citrate ; Tadalafil ; Vardenafil Dihydrochloride

This paper reviewed the efficacy and safety of vardenafil, a highly selective phosphodiesterase type 5 (PDE 5) inhibitor, in men with erectile dysfunction who were difficult to treat. Several large-scale studies indicated vardenafil was effective and safe in the treatment of these difficult-to-treat ED patients, including ED with depression or diabetes, ED after radical retropubic prostatectomy, ED caused by spinal cord injury, and sildenafil nonresponders. Vardenafil provides a rational treatment alternative.
Erectile Dysfunction ; drug therapy ; Humans ; Imidazoles ; therapeutic use ; Male ; Middle Aged ; Phosphodiesterase Inhibitors ; therapeutic use ; Piperazines ; therapeutic use ; Sulfones ; therapeutic use ; Treatment Outcome ; Triazines ; therapeutic use ; Vardenafil Dihydrochloride

Currently, phosphodiesterase type 5 (PDE5) inhibitors are the initial treatment option for erectile dysfunction. The reported efficacy of PDE5 inhibitors is about 70%, although it is significantly lower in difficult-to-treat subpopulations. Treatment failures might be due to the severity of the underlying pathophysiology, improper use of medication, unrealistic patient expectations, difficult relationship dynamics, severe performance anxiety, and other psychological problems. Physicians must address these issues to identify true treatment failures attributable to the drugs. This article discusses factors that might affect the response to PDE5 inhibitors and develops a strategy to maximize the overall efficacy of PDE5 inhibitors in initial non-responders to PDE5 inhibitors.
Carbolines ; Erectile Dysfunction ; Humans ; Imidazoles ; Male ; Performance Anxiety ; Phosphodiesterase 5 Inhibitors ; Piperazines ; Purines ; Sulfones ; Treatment Failure ; Triazines ; Sildenafil Citrate ; Tadalafil ; Vardenafil Dihydrochloride