Katz and colleagues studied the differential effects of OXY-IR versus placebo on memory.21 In a double-blind study, OXY-IR (5–10 mg) caused significant cognitive decrements on 7 of 15 cognitive measures. In a 3-week, randomized, double-blind study, Kay and colleagues noted that OXY-ER resulted in significant memory deterioration compared with placebo, as measured by delayed recall on the Name-Face Association Test at week 3 (mean differences, −1.30; P = .011).22 The dose of OXY-ER used was Inhibitors,research,lifescience,medical 10 mg once daily at week 1, increased to 15 mg daily at week 2, and 20 mg daily by week 3. The drop in cognitive

function was first measured as early as 1 week on the 10-mg dose. In contrast to the high-dose OXY-ER, Lackner and associates studied low-dose OXY-ER 5 mg in a randomized, placebo-controlled trial in cognitively impaired female nursing home residents.23 Low-dose OXY-ER was well tolerated and was found to have no significant change in cognitive function scores at all time points between OXY-ER and placebo. Recently, Inhibitors,research,lifescience,medical OXY-IR, OXY-OTG, and placebo were evaluated Inhibitors,research,lifescience,medical in a short comparative study using cognitive and psychomotor testing.24 OXY-IR demonstrated evidence of impairment

on specific measures of recent memory versus placebo, whereas OXY-OTG and placebo were similar. Despite its limitations, this trial raises the question of whether the CNS effects of oxybutynin could be related to the oxybutynin serum concentration and/or the metabolite DEO.25,26 Clinical trial data support this concept in that transdermal delivery of oxybutynin has the lowest somnolent Inhibitors,research,lifescience,medical (0.3%) and dizziness (1.5%) rate of all delivery methods. Until future research is completed to further substantiate this notion, patients at risk for cognitive impairment should be monitored closely with all forms of oxybutynin. Alternative Non-FDA-Approved Delivery Methods In an effort to check details reduce the side effects of oral oxybutynin, Inhibitors,research,lifescience,medical rectal suppositories and direct bladder instillation of oxybutynin have been studied.27–29 These nontraditional delivery methods

also avoid the presystemic metabolism of oxybutynin and consequently reduce the plasma concentration of DEO. Most of the intravesical Thymidine kinase oxybutynin trials have involved adults and children with neurogenic OAB who were using intermittent catheterization. Several clinical studies have demonstrated significant clinical urodynamic effects including decreased detrusor hyper-reflexia, increased maximum bladder capacity, and decreased detrusor pressure at bladder capacity in neurogenic OAB.30–33 Although the optimum dose for intravesical instillation has not been determined, published studies suggest that an oral dose of 0.2 mg/kg daily (average, 10 mg daily) can be safely used intravesically.29,31 Crushed OXY-IR pills are dissolved in sterile water or saline in concentrations of 5 mg/mL.