Cognitive effects of oxybutynin chloride topical gel in older healthy subjects: a 1-week, randomized, double-blind, placebo- and active-controlled study.
OBJECTIVE
Oxybutynin is a common antimuscarinic therapy for overactive bladder. Transdermally administered oxybutynin chloride topical gel 10% (OTG) has a low propensity for anticholinergic adverse effects and possibly also a low risk of cognitive impairment. A randomized, double-blind, placebo- and active-controlled study evaluated the effects of OTG on cognitive and psychomotor functions in older healthy adults.


METHODS
Healthy adults aged 60-79 years were assigned randomly (1:1:1) to 1-week's treatment with OTG (1 g [100 mg oxybutynin] applied once daily on rotating sites of upper arms/shoulders, abdomen or thighs) plus oral placebo, immediate-release oxybutynin (OXB-IR; 5 mg capsule three times/day) plus placebo gel, or double placebo. Delayed recall Name-Face Association Test (NFAT) score was the primary end point. Treatments were compared by analysis of covariance.


RESULTS
Of 152 participants (mean age, 68 years), 49 received OTG, 52 OXB-IR and 51 placebo. NFAT Delayed Recall tests revealed no significant treatment differences (overall, p = 0.2733; OTG vs placebo, p = 0.1551; OXB-IR vs placebo, p = 0.1767). However, a significant effect (p = 0.0294) was noted for the Misplaced Objects Test, with scores declining only for OXB-IR. Approximately twice as many participants receiving OXB-IR (n = 10) as those receiving OTG (n = 5) or placebo (n = 6) showed a significant decline (≥6 points) in Total Recall score for the Hopkins Verbal Learning Test-Revised. No significant effects on psychomotor reaction time were observed. The most common adverse event, dry mouth, occurred in 6.1%, 73.1% and 7.8% of participants receiving OTG, OXB-IR and placebo, respectively.


CONCLUSIONS
OTG applied for 1 week had no clinically meaningful effect on recent memory or other cognitive functions in healthy, older adults.


BACKGROUND
Registered as NCT00752141 at www.clinicaltrials.gov.
Cognitive Research Corporation, St Petersburg, FL 33701, USA. gkay@cogres.com
Gary G
GG
Kay
David R
DR
Staskin
Scott
S
MacDiarmid
Marilyn
M
McIlwain
Naomi V
NV
Dahl
D000287:Administration, Topical; D000368:Aged; D001288:Attention / Q000187:drug effects; D003071:Cognition / Q000187:drug effects*; D004311:Double-Blind Method; D023381:Endpoint Determination; D005260:Female; D005782:Gels; D006801:Humans; D007858:Learning / Q000187:drug effects; D008297:Male; D008333:Mandelic Acids / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D008568:Memory / Q000187:drug effects; D011939:Mental Recall / Q000187:drug effects; D008875:Middle Aged; D010276:Parasympatholytics / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D011597:Psychomotor Performance / Q000187:drug effects; D011930:Reaction Time / Q000187:drug effects; D053201:Urinary Bladder, Overactive / Q000188:drug therapy* / Q000523:psychology
D005782:Gels; D008333:Mandelic Acids; D010276:Parasympatholytics; C005419:oxybutynin