A Population Pharmacokinetic Model of (R)- and (S-) Oxybutynin and Its Active Metabolites After Oral and Intravesical Administration to Healthy Volunteers.

Oxybutynin is a racemic anticholinergic drug used for the symptomatic treatment of detrusor overactivity. The formation of active metabolites related to tolerability problems depends on the route of administration. The objective of this evaluation was to develop a pharmacokinetic model for oral/intravesical administration as the basis for simulations with different dosages. Data from a published changeover clinical study with 18 healthy adults receiving a single oral dose of 5 mg immediate-release oxybutynin and single and multiple intravesical doses of 10 mg oxybutynin solution was evaluated. Enantioselective plasma concentrations of oxybutynin and N-desethyloxybutynin (NDO) were used to establish a population pharmacokinetic model using nonlinear mixed-effects modeling with NONMEM 7.4.1. For both enantiomers, the data were described well by a 2-compartment model for oxybutynin with an additional compartment for NDO. Oxybutynin absorption was modeled by transit compartments for oral and first-order absorption for intravesical application. Bioavailability of the more active (R)-enantiomer was 7% for oral and 10%-22% for intravesical administration. In simulations, intravesical doses of 5 to 15 mg (R)-oxybutynin administered 2 to 3 times daily decreased peak-trough fluctuations of NDO to 8% compared with 24% after oral administration. The NDO/oxybutynin ratio was reduced from 17 after oral administration to unity. Chronic intravesical versus oral administration of (R)-oxybutynin generates distinctly lower and less variable concentrations of (R)-NDO. Pharmacokinetic simulations suggest that exposure for 12.5 mg (R)-oxybutynin administered twice daily might not compromise efficacy and tolerability compared with exposure for standard thrice-daily administrations. This assumption needs to be assessed in clinical studies.

Long-term results of the treatment of primary hyperhidrosis with oxybutynin: follow-up of 1,658 cases.

BACKGROUND: Hyperhidrosis (HH) is characterized by exaggerated sweating in a specific region due to hyperfunction of the sweat glands. In the late 2000s, we started treating patients with an anticholinergic, oxybutynin, that was not being used until then. OBJECTIVES: To present, after 12 years of utilizing this medication in our service, the substantial experience obtained with the use of oxybutynin as an initial treatment of HH in a large series of 1,658 patients. METHODS: We analyzed 1,658 patients treated with oxybutynin for HH from May 2006 to June 2018. The patients were divided into four groups according to the main site of HH: the plantar group, the axillary group, the facial group, and the palmar group. To measure the degree of satisfaction, a quality of life (QoL) questionnaire was used. RESULTS: Pre-treatment QoL was poor or very poor in more than 94% of the cases, and the palmar group had the worst quality of life. After treatment, we observed an improvement in the quality of life in 77% of patients. More than 70% of the patients in all groups present moderate or optimal subjective clinical improvement in sweating after treatment. The group with the best result was the facial group. Intense dry mouth was reported in 24.9% of all patients in all groups. CONCLUSIONS: This study included a large number of patients followed for a long period and demonstrated the good effectiveness of treatment with oxybutynin for hyperhidrosis in the main sites of sweating.

Comparative study of efficacy and safety of 45% mandelic acid versus 30% salicylic acid peels in mild-to-moderate acne vulgaris.

BACKGROUND: Chemical peels have become a popular modality in the treatment of acne vulgaris (AV). Mandelic acid (MA) is a new emerging peeling agent for AV owing to its antibacterial and anti-inflammatory properties. Hence, it is worthwhile to evaluate the effectiveness and safety profile of this newer agent and to compare it with an older established peeling agent, salicylic acid (SA) in the treatment of AV. OBJECTIVE: Comparison between therapeutic efficacy and safety of 45% MA peel with 30% SA peel in Indian patients suffering from mild-to-moderate facial AV. METHODS: A total of 50 patients suffering from mild-to-moderate AV were randomly divided into two groups, with one receiving 30% SA peels and the other receiving 45% MA peels at an interval of 2 weeks for six sessions. Total duration of the study was 12 weeks. Michaelsson acne scores (MAS) and clinical photographs were used to evaluate the efficacy of therapy objectively. Adverse effects of both the agents were also noted at each visit. RESULTS: Both agents showed almost equal efficacy in improving mild-to-moderate AV. Salicylic acid was found better in treating noninflammatory lesions, while MA had an upper hand in treating inflammatory lesions. Overall, there was no significant difference between the two peels in improving MAS and percentage decrease in MAS. However, adverse effects were lesser with MA peels. CONCLUSION: About 45% MA peel was found to be equally effective as 30% SA peel in mild-to-moderate facial AV. However, safety and tolerability of MA peel were better than SA peel.

Effect of Early Oxybutynin Treatment on Posterior Urethral Valve Outcomes in Infants: A Randomized Controlled Trial.

PURPOSE: We studied the effect of oxybutynin on bladder and upper urinary tract outcomes in infants following posterior urethral valve ablation. MATERIALS AND METHODS: Patients younger than 12 months old who had undergone primary endoscopic valve ablation for posterior urethral valves were screened for eligibility. Patients who had undergone urinary diversion or had other conditions that could affect lower urinary tract function were excluded. Study patients were randomized to either oxybutynin (0.2 mg/kg 3 times daily) until toilet training or active observation. The study end points were serum creatinine, estimated glomerular filtration rate, hydronephrosis improvement, vesicoureteral reflux resolution, febrile urinary tract infection and toilet training. RESULTS: A total of 49 infants (24 receiving oxybutynin and 25 undergoing observation) were enrolled between December 2013 and September 2015 and completed at least 1 year of followup. Oxybutynin was discontinued before toilet training in 5 patients due to facial flushing in 2, bladder and upper tract dilatation in 2, and cognitive changes in 1. After a median followup of 44.2 months (range 12 to 57.6) median serum creatinine and estimated glomerular filtration rate were not significantly different between the groups (p=0.823 and p=0.722, respectively). Renal units in the oxybutynin group had a greater likelihood of hydronephrosis improvement (61.9% vs 34.8%, p=0.011) and resolution of vesicoureteral reflux (62.5% vs 25%, p=0.023). Febrile urinary tract infection (29.2% vs 40%, p=0.404), completion of toilet training (70.8% vs 76%, p=0.748) and age at toilet training (p=0.247) did not differ significantly between the oxybutynin and observation groups. CONCLUSIONS: Oxybutynin enhances hydronephrosis improvement and vesicoureteral reflux resolution following primary endoscopic valve ablation in infants but periodic monitoring is warranted.

Pilot study on the effects of intravesical oxybutynin hydrochloride instillations on the validity of doping control urine samples.

According to class M2.1 of the World Anti-Doping Agency (WADA) Prohibited List, the manipulation of doping control urine samples to alter their integrity and validity is prohibited both in- and out-of-competition. However, some paraplegic athletes with an overactive bladder need to be regularly treated with anti-cholinergic and anti-spasmodic drugs such as oxybutynin, which are often administered intravesically to reduce the substantial side effects observed after oral application. So far, it remains unclear whether such bladder instillations have a negative impact on analytical procedures and thus represent an anti-doping rule violation. Within this pilot study, urine samples were collected from five paraplegic athletes before and after an intravesical oxybutynin hydrochloride instillation. The samples were routinely tested for the presence of performance-enhancing drugs and afterwards fortified with 25 model compounds representing different classes of doping agents (anabolic agents, cannabinoids, diuretics, glucocorticoids, hormone and metabolic modulators, and stimulants) at low and medium concentrations. Additionally, the pH value and specific gravity were measured and the presence of oxybutynin was qualitatively determined by gas chromatography-mass spectrometry (GC-MS). In initial testing procedures, all samples were tested negative. Oxybutynin was present in most of the samples but found to have no significant effect on the detectability of the 25 model compounds subsequently added to each urine specimen. Therefore, it can be concluded that intravesical instillations with oxybutynin hydrochloride do not alter the integrity and validity of doping control urine samples.

Desmopressin and the risk of hyponatremia: A population-based cohort study.

BACKGROUND: Desmopressin was approved by the Food and Drug Administration (FDA) in 1978 for use in diabetes insipidus and bleeding disorders, but it is also prescribed off-label for patients with nocturia. Quantifying the potential risks facing adult patients taking desmopressin has taken on added importance because a new intranasal formulation of desmopressin was approved by the FDA in 2017. Like the old formulation, the main active ingredient is desmopressin acetate, but the new formulation also contains an excipient designed to enhance absorption. Our objective was to quantify the rate of hyponatremia in routine clinical care for patients prescribed the older formulation of desmopressin. METHODS AND FINDINGS: We conducted a population-based new-user cohort study from 1 February 2006 to 1 February 2017 using a nationwide commercial health plan database. Patients newly prescribed the older formulation of desmopressin were propensity-score (PS)-matched to patients newly prescribed oxybutynin. As a sensitivity analysis, tamsulosin was used as the comparator rather than oxybutynin. The primary outcome was a primary position diagnosis of hyponatremia. Proportional hazard models after 1:1 PS matching were used to estimate hazard ratios (HRs) and 95% confidence intervals (CI). We identified 3,137 adults who were newly prescribed desmopressin and matched them to 3,137 adults who were newly prescribed oxybutynin. Mean age was 70, 55% were male, 13% filled a prescription for a diuretic during the baseline time period, and the mean baseline sodium prior to receiving either study drug was 140 mmol/L (normal: 135-145). The rate of hyponatremia was 146 per 1,000 person-years for adults prescribed desmopressin compared to 11 per 1,000 person-years for adults prescribed oxybutynin, corresponding to a 13-fold higher rate (HR 13.19; 95% CI 6.69, 26.01; p < 0.01). When follow-up was truncated at 30 days, a similar increased rate was observed (HR 19.41; 95% CI 7.11, 52.99; p < 0.01). A higher rate of hyponatremia was also observed with desmopressin when tamsulosin was the comparator (HR 12.10; 95% CI 6.54, 22.37; p < 0.01). Important limitations of our study include unmeasured confounding (for example, over-the-counter medication use, dietary intake), missing data (i.e., only 20% of patients had a baseline serum sodium), and a lack of data on the newer formulation of desmopressin. CONCLUSIONS: Use of an older formulation of desmopressin was associated with a marked increased rate of subsequent hyponatremia compared to use of other medications indicated for lower urinary tract symptoms. Such risks should be clearly communicated to patients prescribed this formulation of desmopressin.

Overactive bladder - pharmacological treatment.

The Guidelines Project, an initiative of the Brazilian Medical Association, aims to combine information from the medical field in order to standardize producers to assist the reasoning and decision-making of doctors. The information provided through this project must be assessed and criticized by the physician responsible for the conduct that will be adopted, depending on the conditions and the clinical status of each patient.

Can Oral Fesoterodine Be an Alternative for Intravesical Oxybutynin Instillations in Children with Neuropathic Bladder Dysfunction?

PURPOSE: A low-pressure bladder in children with neuropathic bladder dysfunction can be achieved using anticholinergic medication. Due to the significant side effects of oral oxybutynin, our patients are treated with daily intravesical oxybutynin instillations. Newer oral anticholinergic medication, such as fesoterodine, claim to have fewer side effects in a once daily formulation. Because once-daily oral intake is easier than performing twice-daily intravesical instillations, we studied the effects of switching from intravesical oxybutynin to oral fesoterodine and compared the clinical response, urodynamic parameters and side effects. PATIENTS AND METHODS: Twenty children (11 girls, 9 boys, 4-17 years) with neuropathic bladder dysfunction who perform clean intermittent catheterization and use intravesical oxybutynin instillations twice daily were included in this prospective study. Voiding diaries, a behavioural checklist, urodynamic investigations, vital signs and blood samples were evaluated at baseline during treatment with intravesical oxybutynin and repeated after 40 days of oral fesoterodine. RESULTS: Out of 20, 13 (65%) children showed an identical objective dryness (pad-test), 2 (10%) improved and 5 (25%) got worse. Seven (35%) children reported equal dryness, 7 (35%) reported improvement and 6 (30%) reported that it got worse. From a urodynamic perspective, 13 (65%) children remained identical, 3 (15%) improved and 4 (20%) got worse. Four (20%) children reported a light to moderate dry mouth, 1 (5%) a headache, 1 (5%) behavioural changes during fesoterodine administration, 1 (5%) an increased appetite, 1 (5%) nausea and 1 (5%) hot flushes. CONCLUSIONS: The urodynamics after 40 days of fesoterodine were in 16 (80%) identical or better and could be a safe alternative for oxybutynin instillations in children with neuropathic bladder dysfunction.

Overactive bladder - pharmacological treatment

The Guidelines Project, an initiative of the Brazilian Medical Association, aims to combine information from the medical field in order to standardize producers to assist the reasoning and decision-making of doctors. The information provided through this project must be assessed and criticized by the physician responsible for the conduct that will be adopted, depending on the conditions and the clinical status of each patient.

Adjustment of Conditions for Combining Oxybutynin Transdermal Patch with Heparinoid Cream in Mice by Analyzing Blood Concentrations of Oxybutynin Hydrochloride.

The combination of skin external preparation and transdermal patch is influenced by drug absorption through the skin. We investigated the effect of heparinoid cream on the transdermal absorption of oxybutynin hydrochloride using an oxybutynin transdermal patch and determined the combined effect of these medications. Normal skin and dry dorsal skin in hairless mice were treated with heparinoid cream, followed by the application of the oxybutynin transdermal patch. A blood sample was collected from the mouse tail vein and the blood concentration of oxybutynin hydrochloride was analyzed by LC-MS/MS. Transepidermal water loss, the hydration level of the stratum corneum, and the stratum corneum thickness in the dorsal skin were measured. The blood concentration and area under the curve (AUC)0→24 of oxybutynin hydrochloride increased when the 4.0-cm2 oxybutynin transdermal patch was applied 1 h after the application of the moisturizer, compared to the values without moisturizer. Normal skin and dry skin did not affect this result. As the hydration level of the stratum corneum and stratum corneum thickness increased before patch application by pre-treatment with moisturizer, it was suggested that transdermal absorption of oxybutynin hydrochloride was increased by skin hydration. The increased blood concentration of oxybutynin hydrochloride was regulated by changing the effective area of the patch and applying additional moisturizer at intervals. The pharmacokinetics of oxybutynin hydrochloride under the regulation of combination treatment was similar to that of treatment without moisturizer. These findings indicate that the application conditions of the oxybutynin transdermal patch and heparinoid cream influence the proper use of the patch.

Oral Pharmacologic Management of Overactive Bladder Syndrome: Where Do We Stand?

Overactive bladder syndrome (OAB) is a prevalent disorder with a significant impact on quality of life. Despite this high prevalence, there is significant underdiagnosis and undertreatment due to several barriers, including embarrassment, poor communication and low patient adherence. Currently, various antimuscarinic are available in the treatment of OAB. The introduction of mirabegron has broadened the therapeutic approach and combination therapy of both agents can be valuable in clinical practice. Yet, patient adherence to most drugs for OAB is still relatively poor. Healthcare providers need to identify and utilise strategies to improve treatment adherence by defining clear treatment goals, implement educational methods and frequently communicate with patients to identify problems with adherence. The elderly population form need special attention as in these patients, anticholinergics should be prescribed with care and adequate knowledge regarding pharmacokinetics and drug interactions in essential. Furthermore, patient expectations should be clearly discussed. In this narrative review, the current advances in oral pharmacotherapy are evaluated and the most important factors involved in the management of OAB are discussed.

Cognitive function assessment in elderly patients with overactive bladder treated with transdermal oxybutynin. / Evaluación de la función cognitiva en pacientes de edad avanzada con vejiga hiperactiva tratados con oxibutinina transdémica.

INTRODUCTION AND OBJECTIVES: Older patients with overactive bladder under antimuscarinic treatment are especially susceptible to cognitive impairment. The aim was to assess short term changes in cognitive function in elderly patients with overactive bladder treated with transdermal oxybutynin. MATERIALS AND METHODS: Observational, retrospective, multicentre study in patients with overactive bladder aged 65-80 years undergoing treatment with transdermal oxybutynin. Before and after one month of treatment, cognitive function using the Memory Alteration Test and Clock-Drawing Test, changes in symptoms with validated questionnaires, patient perception of treatment response using Treatment Benefit Scale and treatment adherence with the modified Morisky-Green test, were assessed. RESULTS: From 85 eligible patients, 70 completed the assessment (mean age: 71.4±4.5; BMI: 28.7±3.1kg/m2). No cognitive impairment was observed after one month with transdermal oxybutynin: Memory Alteration Test (+1 point; 95%CI: 0.0-1.5), Clock-Drawing Test (0 points; 95%CI: 0.0-0.0). A statistically significant improvement (P<.001) was observed in all urinary storage symptoms, except stress urinary incontinence. There was an improvement in the Bladder Control Self-Assessment Questionnaire (symptom score: -2.27; 95%CI: -2.8, -1.7; P<.001; bother score: -2.73; 95%CI: -3.3, -2.1; P<.001). 70% of patients reported either a stable or improved bladder condition according to the Patient Perception of Bladder Condition questionnaire. 72.8% of patients reported that their urinary problems had improved or greatly improved with an 84.3% treatment adherence. CONCLUSIONS: No cognitive impairment was observed in elderly patients after one month of treatment with transdermal oxybutynin; urinary urgency symptoms improved and there was adequate treatment adherence.

Simultaneous quantification of oxybutynin and its active metabolite N-desethyl oxybutynin in rat plasma by ultra-high-performance liquid chromatography-tandem mass spectrometry and its application in a pharmacokinetic study of oxybutynin transdermal patch.

A rapid, selective and sensitive ultra-high-performance liquid chromatography-tandem mass spectrometry method was developed to simultaneously determine oxybutynin and its active metabolite N-desethyl oxybutynin in rat plasma. A 0.1 mL sample of plasma was extracted with n-hexane. Chromatographic separation was performed on a UPLC BEH C18 column (2.1 × 100 mm i.d.,1.7 µm) with mobile phase of methanol-water (containing 2 mmol/L ammonium acetate and 0.1% formic acid; 90:10, v/v). The detection was performed in positive selected reaction monitoring mode. Each plasma sample was chromatographed within 3 min. The linear calibration curves were obtained in the concentration range of 0.0944-189 ng/mL (r ≥ 0.99) for oxybutynin and 0.226-18.0 ng/mL (r ≥ 0.99) for N-desethyl oxybutynin. The intra- and inter-day precision (relative standard deviation) values were not more than 14% and the accuracy (relative error) was within ±7.6%. The method described was superior to previous methods for the quantitation of oxybutynin with three product ions and was successfully applied to a pharmacokinetic study of oxybutynin and its active metabolite N-desethyl oxybutynin in rat plasma after transdermal administration.

Intradetrusor onabotulinumtoxinA injections are significantly more efficacious than oral oxybutynin for treatment of neurogenic detrusor overactivity: results of a randomized, controlled, 24-week trial.

OBJECTIVE: To prospectively compare the results of intradetrusor onabotulinumtoxinA injections and oral oxybutynin for urinary continence, urodynamic parameters and quality of life in patients with neurogenic detrusor overactivity due to spinal cord injury. METHODS: Adult patients under intermittent catheterization were randomized 1:1 to receive one injection of onabotulinumtoxinA 300U or oxybutynin 5mg, per oris, three times/day. Primary study endpoint was change in urinary incontinence episodes/24 hours and secondary study endpoints were maximum cystometric capacity, maximum detrusor pressure, bladder compliance and quality of life before randomization and at week 24. RESULTS: Sixty-eight patients participated in the trial. Significant improvements in urinary incontinence per 24 hours, all investigated urodynamic parameters and quality of life were observed in both groups. Compared with oral oxybutynin, onabotulinumtoxinA was significantly more efficacious for all parameters investigated. Non-response to treatment was higher for oral oxybutynin (23.5%) than onabotulinumtoxinA (11.8%). Dry mouth was the most common adverse in patients with oral oxybutynin (72%) and transient macroscopic hematuria in patients with onabotulinumtoxinA (28%). Only one patient with oral oxybutynin dropped out the study because of adverse effects. CONCLUSION: The comparison of the two study drugs showed that onabotulinumtoxinA was significantly more efficacious than oral oxybutynin with regard to continence, urodynamic parameters and quality of life. Clinicaltrials.gov: NCT:01477736.

Short-term benefit of smoking cessation along with glycopirronium on lung function and respiratory symptoms in mild COPD patients: a retrospective study.

INTRODUCTION: Tobacco smoke is the leading cause of chronic obstructive pulmonary disease (COPD). Smoking cessation can change the natural history of COPD, as we know from the GOLD guidelines. Little is known about the short-term clinical and functional effects of smoking cessation treatment combined with anti-muscarinic bronchodilators. OBJECTIVE: To determine whether quitting smoking, obtained by smoking cessation treatment combined with the use of a new long-acting muscarinic antagonist bronchodilator (LAMA), can improve lung function tests and respiratory symptoms more than the use of LAMA alone. METHODS: We evaluated, in a retrospective analysis, the functional and clinical data, collected in one year, of 120 patients who were current smokers affected by mild COPD and who quit smoking using smoking cessation treatment combined with glycopirronium. We compared them with a group of 80 patients with mild COPD undergoing the same treatment but who did not quit smoking. All patients underwent functional and clinical tests at baseline and at a third-month check. MEASUREMENTS AND MAIN RESULTS: The two groups were homogeneous in terms of demographic data without significant differences. All patients used varenicline for smoking cessation. They all performed the following tests: a spirometry with detection of resistances, the 6 min walking test, haemogasanalysis, the exhaled CO test, the COPD assessment test (CAT) and finally the modified Medical Research Council test (mMRC). A significant improvement in the functional tests at the third-month check was found in both groups-quitters and non-quitters. However, a notable increase in the examined parameters was registered in the group of patients who quit smoking, in particular, we observed a significant increase at the third-month check of the parameter forced expiratory volume in 1 s (FEV1) of more than 200 ml with p < 0.001. A comparison between quitters and non-quitters revealed a major benefit derived from smoking cessation in terms of functional changes and symptom relief. In particular, not only FEV1 but also forced expiratory flow at 25%-75% of vital capacity (FEF 25-75) (p < 0.01) and CAT (p < 0.001) were found to be significantly improved in patients who quit than in patients who did not at the check time point. CONCLUSIONS: Smoking cessation treatment obtained by varenicline was confirmed as a crucial therapeutic option, especially when combined with bronchodilator in mild COPD. Patients who quit smoking could already benefit from both treatments in the short term, improving lung function and respiratory symptoms and therefore improving their quality of life.

Investigation of molecular mobility of pressure-sensitive-adhesive in oxybutynin patch in vitro and in vivo: Effect of sorbitan monooleate on drug release and patch mechanical property.

The aim of present study was to develop an oxybutynin (OXY) transdermal patch with good permeation behavior and mechanical property. Special attention was paid to the effect of chemical enhancer on the molecular mobility of pressure sensitive adhesive (PSA) at molecular level. PSAs and permeation enhancers were investigated through in vitro experiment using rat skin. The optimized formulation was evaluated through pharmacokinetic study using rat. In addition, the molecular mechanism of sorbitan monooleate (Span® 80) in the improvement of PSA molecular mobility was investigated using FT-IR, molecular dynamics simulation, DSC and rheological study. As a result, the optimized formulation using amide PSA demonstrated good adhesion property. And the AUC0-t and Cmax of optimized patch were 6435.8 ±â€¯747.8 h ∗ ng/mL and 127.8 ±â€¯18.0 ng/mL, respectively, which had no significant difference with commercial product. Furthermore, the improvement of the PSA mobility by Span® 80 rather than the decrease of interaction between drug and PSA was the main factor that enhanced the release of OXY from patch. In conclusion, a drug-in-adhesive OXY patch was developed, and the effect of PSA molecular mobility increase on the enhancement of drug skin permeation was proposed at molecular level.

[Maintenance of the efficacy of the oxybutynin patch for the treatment of overactive bladder syndrome despite the change in the area of application: study of four cases.] / Mantenimiento de la eficacia ante el cambio en la zona de aplicación del parche de oxibutinina para el tratamiento del síndrome de vejiga hiperactiva: estudio de cuatro casos.

The transdermal route for administration of anticholinergic drugs can provide efficacy with less systemic adverse effects. The transdermal oxybutynin patch (OXYTDS) offers advantages over oral administration for patients treated for Overactive bladder (OAB) syndrome. The limited evidence on the OXY-TDS patch application areas of the skin, makes difficult counseling patients who require a change to skin zones other than those recommended by the manufacturer. The preliminary experience of four patients included in this case report suggests that changing the application area for the OXY-TDS patch outside those skin areas recommended by the manufacturer, seems effective and safe in the treatment of OAB syndrome, regardless of the characteristics of the patients.

Adjusting oral oxybutynin medication for hyperhidrosis to reflect seasonal temperature variations.

Most studies of oral oxybutynin (OOx) for the treatment of hyperhidrosis (HH) have assumed a stable treatment protocol, without taking into account adverse effects (AE) or seasonal variations in temperature. The objective is to evaluate adjusting the dose of OOx according to the time of year. Prospective study of patients who began OOx for HH between 2007 and 2017, and maintained treatment for at least 1 year, with a progressively increasing dose was performed. All patients were recommended to vary the dose of medication according to the time of year. Baseline epidemiological data, the response to treatment and AE were analyzed. About 122 patients were included (average age of 33.8 years). Up to 60.7% varied the dose. Significantly better results were obtained in the group that varied the dose. Twenty patients suspended the treatment in winter. Among them the adjusted OR was 3.04 (95% CI 1.24-7.45) for an excellent response. The frequency of AE was 74.6% with no differences among groups. Most patients are able to control their HH without requiring the same dose of OOx throughout the year. Given that the possible AE of OOx are dose-dependent, it seems reasonable to vary it according to the time of year.

Oxybutynin 3% gel for the treatment of primary focal hyperhidrosis in adolescents and young adults.

BACKGROUND/OBJECTIVES: There are no reliably effective, well-tolerated topical agents for the treatment of hyperhidrosis. We sought to evaluate the efficacy and tolerability of oxybutynin 3% gel in adolescents and young adults with primary focal hyperhidrosis. METHODS: Patients with severe axillary hyperhidrosis were treated with topical oxybutynin 3% gel for 4 weeks. Response to treatment was assessed by calculating change in Hyperhidrosis Disease Severity Score from baseline to weeks 1 and 4. Change in health-related quality of life was assessed using the Children's Dermatology Life Quality Index or the Dermatology Life Quality Index. Adverse effects were evaluated using patient diaries, investigator global review, and physical examination. RESULTS: Of 10 patients aged 13-24 enrolled, seven completed the study. Of those who completed the study, four (57.1%) reported reduction in axillary Hyperhidrosis Disease Severity Score at week 1 and all seven (100%) at week 4. Six patients (85.7%) reported reduction in Children's Dermatology Life Quality Index or Dermatology Life Quality Index score. Anticholinergic adverse effects were infrequent. The majority of treatment-related adverse events were mild to moderate in severity. One patient experienced a severe adverse event. CONCLUSION: Oxybutynin 3% gel reduced hyperhidrosis severity and improved health-related quality of life in this small pilot study. Safety and efficacy should be further evaluated in a large, prospective, placebo-controlled study.