Name the category.
Genitourinary Agents.
Name the main drug.
Oxybutynin
In which category can Oxybutynin be grouped?
Tertiary amines
Lipophilic (good oral bioavailability and CNS penetration)
Describe the effect.
↓ Tone and motility of smooth muscle cells
What is the indication?
↓ Bladder spasms and urgency in overactive bladder incontinence
List common adverse effects.
Conventional or extended-release tablets or oral solution: dry mouth, dizziness, constipation, somnolence, impaired urination, nausea, blurred vision, dyspepsia, asthenia, pain, abdominal pain, headache, rhinitis, dry eyes, diarrhea, increased post-void residual volume, urinary tract infection.
Transdermal system: application site reactions (e.g., pruritus, erythema, rash, vesicles, macules), dry mouth, constipation, diarrhea, abnormal vision, dysuria.
Describe the mechanism of action.
Racemic mixture of R- and S-isomers. [ref] Antimuscarinic activity resides predominantly in the R-isomer. [ref] Free base (oxybutynin) pharmacologically equivalent to oxybutynin chloride.
Chemically and pharmacologically similar to some anticholinergic, antispasmodic, local anesthetic, and antihistaminic compounds.
Exerts a direct spasmolytic action and inhibits the muscarinic action of acetylcholine on smooth muscle.
Acts as a competitive antagonist of acetylcholine at postganglionic muscarinic receptors, resulting in relaxation of bladder smooth muscle. In patients with uninhibited neurogenic and reflex neurogenic bladders, oxybutynin diminishes the frequency of uninhibited contractions of the detrusor muscle and delays the initial desire to void, resulting in decreased urgency and the frequency of incontinent episodes and voluntary urination.
Does not appear to exhibit antinicotinic effects (i.e., block acetylcholine effects at skeletal myoneural junctions or at autonomic ganglia)
Last changeda year ago