Is oxybutynin sedating
) is an anticholinergic medication used to relieve urinary and bladder difficulties, including frequent urination and inability to control urination (urge incontinence), by decreasing muscle spasms of the bladder. It also has direct spasmolytic effects on bladder smooth muscle as a voltage-gated calcium channel antagonist and local anesthetic, but at concentrations far above those used clinically. The (R)-enantiomer is a more potent anticholinergic than either the racemate or the (S)-enantiomer, which is essentially without anticholinergic activity at doses used in clinical practice.
Oxybutynin is also a possible treatment of hyperhidrosis (hyperactive sweating). However, (R)-oxybutynin administered alone offers little or no clinical benefit above and beyond the racemic mixture.
The other actions (calcium antagonism, local anesthesia) of oxybutynin are not stereospecific.
(S)-Oxybutynin has not been clinically tested for its spasmolytic effects, but may be clinically useful for the same indications as the racemate, without the unpleasant anticholinergic side effects.
In two trials of patients with overactive bladder, transdermal oxybutynin 3.9 mg/day decreased the number of incontinence episodes and increased average voided volume to a significantly greater extent than placebo.
There was no difference between transdermal oxybutynin and extended-release oral tolterodine.
Oxybutynin's tendency to reduce sweating can be dangerous.
The long-acting formulations also allow once-daily administration instead of the twice-daily dosage required with the immediate-release form.
The transdermal patch, in addition to the benefits of the extended-release oral formulations, bypasses the first-pass hepatic effect that the oral formulations are subject to.
In those with overflow incontinence because of diabetes or neurological diseases like multiple sclerosis or spinal cord trauma, oxybutynin can worsen overflow incontinence since the fundamental problem is that the bladder is not contracting.
A large study linked the development of Alzheimer's disease and other forms of dementia in those over 65 to the use of oxybutynin, due to its anticholinergic properties.
Oxybutynin chloride exerts direct antispasmodic effect on smooth muscle and inhibits the muscarinic action of acetylcholine on smooth muscle.