Clindamycin phosphate 1.2%/benzoyl peroxide 3% fixed-dose combination gel versus topical combination therapy of adapalene 0.1% gel and clindamycin phosphate 1.2% gel in the treatment of acne vulgaris in Japanese patients: A multicenter, randomized, investigator-blind, parallel-group study.

Adapalene 0.1% (ADA) with clindamycin phosphate 1.2% (CLNP; ADA + CLNP) and the fixed-dose combination containing CLNP and benzoyl peroxide 3% (CLNP/BPO 3%) are strongly recommended for the early treatment of acne vulgaris in Japan. Here, we compare the early efficacy and safety of CLNP/BPO 3% with Japanese standard topical use of ADA + CLNP in the treatment of acne vulgaris. In this phase IV, multicenter study, 351 patients were randomized to receive CLNP/BPO 3% or ADA + CLNP for 12 weeks. The primary end-point was percentage change from baseline in total lesion (TL) counts at week 2. Secondary end-points included the percentage change from baseline in TL, inflammatory and non-inflammatory lesion (IL and non-IL) counts, Investigator's Static Global Assessment (ISGA), quality of life (QoL [Skindex-16]) and patient preference. Local tolerability scores and adverse events were also recorded. CLNP/BPO 3% provided a significantly greater percentage reduction from baseline in TL compared with ADA + CLNP at week 2, and week 4. Compared with ADA + CLNP, CLNP/BPO 3% was superior at reducing IL (but not non-IL) over weeks 2-12, was more effective at improving patient QoL and ISGA, and scored higher in patient-preference assessments. Both treatments were well tolerated; adverse drug reactions occurred more frequently in patients receiving ADA + CLNP (37%) than in those receiving CLNP/BPO 3% (17%). In conclusion, CLNP/BPO 3% showed greater efficacy for the early treatment of acne vulgaris in Japan, with a more favorable safety profile compared with ADA + CLNP.

Understanding patient and physician perceptions of male androgenetic alopecia treatments in Asia-Pacific and Latin America.

This survey aimed to explore patient and physician attitudes towards male androgenetic alopecia (AGA), satisfaction with currently available male AGA treatments and investigate the factors affecting treatment choice. The survey was carried out in five countries (Japan, South Korea, Taiwan, Mexico and Brazil) between November and December 2015 using a standard market research methodology. Questionnaires were completed by patients with male AGA or hair loss/thinning and practicing physicians who were responsible for prescribing AGA treatment. In total, 835 patients and 338 physicians completed the questionnaire. Overall, 37.6% of patients reported satisfaction with the treatments they had used. The highest patient satisfaction was reported for 5-alpha-reductase inhibitors (53.9% of patients satisfied). In all countries, physicians were more likely than patients to think that male AGA has a major impact on patient confidence (89.3% vs 70.4%, respectively). There was agreement by physicians and patients that male AGA patients who are involved in their treatment decisions have better outcomes. Patients who were satisfied with AGA treatments were more likely to have the level of involvement they desired in treatment decisions (69.1% of satisfied patients) than dissatisfied patients (56.4% of dissatisfied patients). This survey provides valuable insights into the attitudes of patients and physicians in Asia and Latin America about male AGA and its treatments. The survey identified areas of disconnect between physicians and patients regarding the impact of male AGA, treatment consultations and the importance of treatment attributes. It also highlights the need for physicians to spend sufficient time with patients discussing AGA treatment approaches.

The new radioligand [(3)H]-L 748,337 differentially labels human and rat ß3-adrenoceptors.

As no suitable radioligand exists for the detection of ß3-adrenoceptors, we have explored the radioligand binding properties of a tritiated version of the selective ß3-adrenoceptor antagonist L 748,337. Kinetic and equilibrium saturation and competition binding experiments were performed with [(3)H]-L 748,337 on membrane fractions of HEK and CHO cells stably transfected with human and rat ß-adrenoceptor subtypes. Based on both association/dissociation kinetic and equilibrium saturation binding studies in transfected HEK cells, [(3)H]-L 748,337 exhibited an affinity of approximately 2 nM for human ß3-adrenoceptors. Competition studies with agonists and subtype-selective antagonists validated its binding to ß3-adrenoceptors. In CHO cells transfected with human ß3-adrenoceptors similar saturable high-affinity of [(3)H]-L 748,337 was observed. While some isoprenaline-sensitive [(3)H]-L 748,337 binding was also observed in CHO cells transfected with human ß1- or ß2-adrenoceptors, this was not saturable in a similar concentration range and/or not sensitive to the antagonists propranolol and SR 59,230, indicating that it did not primarily involve ß-adrenoceptors. In CHO cells transfected with rat ß3-adrenoceptors [(3)H]-L 748,337 exhibited a considerably lower affinity than with the human subtype (12-95 nM). Low affinity for the rat ß3-adrenoceptor was also found with unlabelled L 748,337 in rat bladder strip relaxation experiments. We conclude that L 748,337 apparently has lower affinity for the rat than the human ß3-adrenoceptors and that [(3)H]-L 748,337 can bind to a low-affinity site distinct from the orthosteric pocket of ß-adrenoceptors. Nevertheless, [(3)H]-L 748,337 appears to be the most promising radioligand for the selective labelling of human ß3-adrenoceptors reported to date.

Pharmacological profile of the selective ß3-adrenoceptor agonist mirabegron in cynomolgus monkeys.

Mirabegron is a novel ß3-adrenoceptor agonist developed for the treatment of overactive bladder. To clarify the relationship between the pharmacological effects of mirabegron in monkeys and the clinical efficacy in patients with overactive bladder, the effect of mirabegron on bladder function was evaluated using cynomolgus monkeys. Quantitative PCR revealed that mRNA expression of ß3-adrenoceptors was most abundant (98 %) among ß-adrenoceptor subtypes in the bladder of cynomolgus monkeys. Mirabegron, which showed selective and potent agonistic activity on monkey ß3-adrenoceptors expressed in Chinese hamster ovary cells with EC50 value of 32 nmol/L and intrinsic activity of 0.8, induced concentration-dependent relaxation of bladder smooth muscle strips isolated from cynomolgus monkeys with EC50 values of 120 nmol/L in 20 mmol/L KCl stimulation and 43 nmol/L under 9.81 mN resting tension. In conscious cynomolgus monkeys, mirabegron decreased micturition frequency at oral doses of 1 and 3 mg/kg and increased mean volume voided per micturition at an oral dose of 3 mg/kg. Plasma concentration at which bladder function improved in the cynomolgus monkeys was similar to that at the clinically effective dose in patients with overactive bladder. These data suggest that the relaxant function in monkey bladder is mainly mediated by ß3-adrenoceptors similar to that in the human bladder and mirabegron showed efficacy on the bladder functions of the same parameters in clinical evaluation endpoints.

Effect of mirabegron, a novel ß3-adrenoceptor agonist, on bladder function during storage phase in rats.

Mirabegron, a selective ß(3)-adrenoceptor agonist, facilitates urine storage function by exerting a relaxing effect on bladder smooth muscle. Here, we investigated the effect of mirabegron on bladder function during the storage phase. We assessed the effect of mirabegron on the resting intravesical pressure in anesthetized rats and also tested antimuscarinics (oxybutynin and tolterodine) under the same experimental conditions. Mirabegron dose-dependently decreased the resting intravesical pressure, while oxybutynin and tolterodine showed no statistically significant effects on resting intravesical pressure. We also investigated the effect of mirabegron on bladder function using cystometry technique in conscious rats with bladder outlet obstruction. While mirabegron dose-dependently decreased the frequency of nonvoiding contractions, considered an index of abnormal response in bladder storage, no significant effects were noted on the amplitude of nonvoiding contractions, micturition pressure, threshold pressure, voided volume, residual volume, or bladder capacity. Neither oxybutynin nor tolterodine affected the frequency of nonvoiding contractions; however, oxybutynin increased residual volume and tended to decrease voided volume in a dose-dependent manner, and tolterodine dose-dependently decreased voided volume. Taken together, these results shed light on the suggestion of mirabegron as a therapeutic agent, compared with antimuscarinics, with its most prominent effect being the facilitation of bladder storage.

In vitro and in vivo pharmacological profile of the selective ß3-adrenoceptor agonist mirabegron in rats.

To investigate the pharmacological properties of mirabegron in in vitro and in vivo, the effects on cAMP accumulation in Chinese hamster ovary (CHO) cells expressing rat ß-adrenoceptors, the relaxant activity in isolated rat bladder smooth muscle, and the voiding effects in cerebral infarcted rats were evaluated. Mirabegron increased cAMP accumulation with EC(50) value and intrinsic activity of 19 nmol/L and 1.0, respectively, in CHO cells expressing rat ß(3)-adrenoceptors. The EC(50) values and the intrinsic activities of mirabegron were 610 nmol/L and 0.6 for rat ß(1)-adrenoceptors and were sumless and 0.1 for ß(2)-adrenoceptors, respectively. Mirabegron showed concentration-dependent relaxant and full agonistic effects in rat bladder strips under passive tension with EC(50) value of 290 nmol/L. The concentration-response curve of mirabegron was affected neither by the ß(1)-adrenoceptor selective antagonist CGP-20712A nor by the ß(2)-adrenoceptor selective antagonist ICI-118,551. In in vivo studies with cerebral infarcted rats, a significant decrease in the volume voided per micturition compared with sham-operated rats was observed. Mirabegron dose-dependently increased the volume voided per micturition. In conclusion, we have extended the selectivity profile of mirabegron to rats and demonstrated that it is effective via stimulation of ß(3)-adrenoceptors in a rat cerebral infarction model of detrusor overactivity.

Effects of α1-adrenoceptor antagonists on phenylephrine-induced salivary secretion and intraurethral pressure elevation in anesthetized rats.

α(1)-Adrenoceptor antagonists are widely used for the treatment of voiding dysfunction associated with benign prostatic hyperplasia. Activation of α(1)-adrenoceptors is reported to induce salivary secretion in rats and humans. However, the effects of α(1)-adrenoceptor antagonists on salivary secretion remain unknown. Here, we investigated the effects of the α(1)-adrenoceptor antagonists prazosin, silodosin, tamsulosin and urapidil on phenylephrine-induced salivary secretion and compared the results with the effects on phenylephrine-induced intraurethral pressure (IUP) elevation in anesthetized rats. All antagonists inhibited phenylephrine-induced salivary secretion and IUP elevation in a dose-dependent fashion. Comparison of DR(10) values (the dose required to shift the dose-response curve 10-fold to the right) in both tissues showed that the inhibitory effect of silodosin was significantly more potent in the salivary gland than in the urethra (18-fold), but tamsulosin (2.3-fold), prazosin (1.7-fold) and urapidil (1.1-fold) did not show comparable tissue selectivity. These results suggest that α(1)-adrenoceptor antagonists inhibit not only urethral contraction but also salivary secretion, and that high tissue selectivity for the salivary gland over the urethra as shown by silodosin may contribute to the incidence of dry mouth.

Tamsulosin potently and selectively antagonizes human recombinant α(1A/1D)-adrenoceptors: slow dissociation from the α(1A)-adrenoceptor may account for selectivity for α(1A)-adrenoceptor over α(1B)-adrenoceptor subtype.

We determined the binding affinity of tamsulosin, a selective α(1)-adrenoceptor antagonist, for human α(1)-adrenoceptor subtypes in comparison with those of other α(1)-adrenoceptor antagonists including silodosin, prazosin, 5-methylurapidil, terazosin, alfuzosin, nafopidil, urapidil and BMY7378. The association and dissociation kinetics of [(3)H]tamsulosin for recombinant human α(1)-adrenoceptor subtypes were compared with those of [(3)H]prazosin. Tamsulosin competitively inhibited [(3)H]prazosin binding to human α(1A)-, α(1B)- and α(1D)-adrenoceptors (pK(i) values were 10.38, 9.33, 9.85) indicating 11 and 3.4-fold higher affinities for human α(1A)-adrenoceptor than those for α(1B)- and α(1D)-adrenoceptors, respectively. The affinity of tamsulosin for the human α(1A)-adrenoceptor was, respectively, 5, 9.9, 38, 120, 280, 400, 1200 and 10000 fold higher than those of silodosin, prazosin, 5-methylurapidil, terazosin, alfuzosin, naftopidil, urapidil and BMY7378, respectively. [(3)H]Tamsulosin dissociated from the α(1A)-adrenoceptor slower than from the α(1B)- and α(1D)-adrenoceptors (α(1B)>α(1D)>α(1A)). Moreover, [(3)H]tamsulosin dissociated slower than [(3)H]prazosin from the α(1A)-adrenoceptor and faster from the α(1B)- and α(1D)-adrenoceptors. In conclusion, tamsulosin potently and selectively antagonized α(1A/1D)-adrenoceptor ligand binding, and slowly dissociated from the α(1A)-adrenoceptor subtype.

Relationship between the functional effect of tamsulosin and its concentration in lower urinary tract tissues in dogs.

We investigated the relationship between the pharmacological effect of tamsulosin and its concentrations in plasma and several lower urinary tract (LUT) and arterial tissues in conscious male dogs. Oral administration of tamsulosin (30 and 100 microg/kg) inhibited phenylephrine-induced intraurethral pressure (IUP) elevation. Inhibition peaked at 1, 2 h after dosing and lasted up to 6--8 h. Basal mean blood pressure did not significantly change throughout the observation period. Plasma concentration reached maximum within 0.5 h after dosing, whereas that in LUT tissues (prostate, urethra and bladder) reached maximum at 1, 2 h, and prostatic and urethral concentrations remained higher than those in plasma and arterial tissues at almost all observation points. Prostatic concentrations of tamsulosin at individual time points were 2.2- to 18.0-fold higher than plasma and 3.7- to 12.3-fold higher than mesenteric artery concentrations. Urethral concentrations of tamsulosin were also higher than those in both plasma and mesenteric artery. The prostatic and urethral concentrations of tamsulosin correlated well with its effect on IUP response [r2 = 0.98 (p<0.01) and r2 = 0.99 (p<0.01), respectively]. Our data demonstrate that tamsulosin is selectively retained in LUT tissues compared with plasma and arterial tissues and that its sustained effect on IUP response appears to be related to the prostatic and urethral retention of tamsulosin.

Pharmacological characterization of a new antimuscarinic agent, solifenacin succinate, in comparison with other antimuscarinic agents.

Solifenacin succinate [YM905; (3R)-1-azabicyclo[2.2.2]oct-3-yl(1S)-1-phenyl-3,4-dihydroisoquinoline-2(1H)-carboxylate monosuccinate] is a new muscarinic receptor antagonist developed for the treatment of overactive bladder. The aim of the present study was to evaluate the antimuscarinic properties of solifenacin and to compare the results with those obtained for tolterodine, oxybutynin, darifenacin, propiverine and atropine. In radioligand receptor binding assay, Ki values of solifenacin for human muscarinic M1, M2, M3, M4 and M5 receptors were 26, 170, 12, 110 and 31 nM, respectively. In isolated rat urinary bladder, solifenacin competitively antagonized carbachol-induced contractions, with a pA2 value of 7.44+/-0.09. In these in vitro studies, the antimuscarinic action of solifenacin was more potent than that of propiverine and less potent than those of tolterodine, oxybutynin, darifenacin and atropine. In anesthetized rats, solifenacin and oxybutynin increased the maximum bladder capacity in a dose-dependent manner and also decreased the maximum intravesical pressure. The dosages required to produce a 30% increase in maximum bladder capacity (ED30 values) of solifenacin and oxybutynin were 0.35 and 0.30 mg/kg i.v., respectively, indicating approximately equal efficacies. These results support the fact that solifenacin, similarly to currently used antimuscarinic agents, is an effective agent in the treatment of overactive bladder symptoms such as urinary frequency and urge incontinence.

In vitro and in vivo tissue selectivity profile of solifenacin succinate (YM905) for urinary bladder over salivary gland in rats.

Solifenacin succinate [YM905; (+)-(1S,3'R)-quinuclidin-3'-yl 1-phenyl-1,2,3,4-tetrahydroisoquinoline-2-carboxylate monosuccinate] is a new muscarinic receptor antagonist developed for the treatment of overactive bladder. The aim of the present study was to evaluate the in vitro and in vivo bladder selectivity profile of solifenacin over salivary gland in the same animal species, and to compare the results with those obtained for tolterodine, oxybutynin, darifenacin and atropine. Solifenacin and the other antimuscarinic drugs inhibited carbachol-induced increases in intracellular Ca(2+) levels in bladder smooth muscle cells and salivary gland cells isolated from rats in a concentration-dependent manner. The inhibitory effect of solifenacin for bladder smooth muscle cells (pK(i)=8.12) was 3.6-fold more potent than that for salivary gland cells (pK(i)=7.57). In contrast, the inhibitory effects of the other antimuscarinic drugs for bladder smooth muscle cells were 1.7- to 2.2-fold more potent than those for salivary gland cells. In anesthetized rats, solifenacin dose-dependently inhibited carbachol-induced intravesical pressure elevation and salivary secretion, and exhibited functional selectivity (3.7- to 6.5-fold) for urinary bladder over salivary gland. Tolterodine was also 2.2- to 2.4-fold more selective in inhibition of bladder response. In contrast, oxybutynin, darifenacin and atropine did not show functional selectivity for urinary bladder. These results indicate that solifenacin exerts greater selectivity for urinary bladder over salivary gland than tolterodine, oxybutynin, darifenacin and atropine, and may consequently provide symptomatic benefit in the treatment of overactive bladder with less dry mouth than currently used antimuscarinic drugs.