Trospium

Trospium is a prescription drug used to treat the symptoms of overactive bladder, such as urinary incontinence, urgency, and frequent urination.

Trospium belongs to a family of drugs called antimuscarinics. Other members of this family include atropine, hyoscine, ipratropium, tropicamide, cyclopentolate and pirenzepine. All antimuscarinic drugs affect the autonomic nervous system by blocking the ability of the normal neurotransmitter, acetylcholine, to bind to muscarinic receptors. Acetylcholine helps control many muscular activities, such as the rhythmic contraction of the gut or the urinary bladder's contracting to cause urination. Drugs such as trospium that act on the muscarinic receptors can either increase or decrease the normal activity of the automonic nervous system.

The Food and Drug Administration approved trospium on May 28, 2004.

Other Names
Trospium was developed by Indevus Pharmaceuticals and is co-marketed by Allergan under the brand name Sanctura.

Uses
Trospium is used for the treatment of overactive bladder with symptoms of urinary incontinence, urgency, and urinary frequency.

How Trospium is Taken
The recommended dose is 20 mg twice daily. Trospium should be taken on an empty stomach.

How Trospium Works
Trospium is an antimuscarinic drug that works by inhibiting the effect of acetylcholine on muscarinic receptors in the smooth muscle of the bladder. This inhibitory action "softens the tone" of the bladder muscles, which improves the urinary symptoms associated with overactive bladder.

How the Body Affects Trospium
After dosing, less than 10% of the original dose is absorbed. Peak circulating levels occur between five and six hours after administration.

The major metabolic pathway is not known, but the liver is NOT significantly involved in metabolizing trospium.

The majority of the original dose (85%) is excreted in the feces and a smaller amount (6% of the dose)is excreted in the urine.

Side Effects
The most common side effects (in >1% of patients) directly associated with trospium are:


 * gastrointestinal disorders
 * dry mouth
 * constipation
 * abdominal pain
 * constipation aggravated
 * dyspepsia
 * flatulence
 * nervous system disorders
 * headache
 * fatigue
 * kidney and urinary disorders
 * urinary retention
 * eye disorders
 * dry eyes

Risks and Precautions
As mentioned earlier, trospium is an antimuscarinic drug. Antimuscarinics like trospium belong to a larger family called anticholinergics. All anticholinergics may produce serious side effects besides the common ones listed above.

For example, heat prostration (fever and heat stroke due to decreased sweating) can occur when trospium is taken in a hot climate.

Because trospium may also produce dizziness or blurred vision, caution is to be exercised in tasks requiring mental alertness such as driving. Moreover, alcohol may worsen the drowsiness caused by trospium.

Other anticholinergics
The use of trospium with other anticholinergic drugs produces dry mouth and constipation. Anticholinergic agents may alter the absorption of other drugs since anticholinergics affect gut motility.

Drugs eliminated by the kidney tubules
Trospium has the potential for interacting with other drugs that are eliminated by tubular secretion in the kidney. These include:
 * digoxin
 * procainamide
 * pancuronium
 * morphine
 * vancomycin
 * metformin
 * tenofovir

Effectiveness
The effectiveness of trospium was evaluated for the treatment of patients with overactive bladder who had symptoms of urinary frequency, urgency, and incontinence in two U.S. studies:


 * One study involved 523 patients with a total of 262 patients receiving trospium 20 mg twice daily and 261 patients receiving placebo. Trospium significantly reduced urinary frequency and urinary void volume compared to placebo.


 * A second study involved 329 patients receiving trospium 20 mg twice daily and 329 patients receiving placebo. Trospium significantly reduced urinary frequency, episodes of urge incontinence, and urinary void volume compared to placebo.