Detailed Drug Information:

DRUG CLASS AND MECHANISM: Tolterodine belongs to a class of drugs called cholinergic (acetyl-choline) receptor blockers. It is used to treat disorders of the urinary bladder that affect urination.

The urinary bladder is a muscular "bag." Urine coming from the kidneys fills the bladder and causes it to stretch like a balloon. As it stretches, pressure in the bladder increases and, when the bladder reaches a certain level of stretch, a desire to urinate is felt. Nerves in the muscular wall of the bladder release acetyl-choline, a chemical that attaches to receptors on the muscle cells and causes the cells to contract (tighten). This contributes further to the increase in pressure within the bladder and the desire to urinate. At the appropriate time (e.g., when a toilet is available), there is conscious relaxation of the muscle at the outlet of the bladder, and the high bladder pressure forces urine out of the bladder. Normally, urination is under conscious control; however, in some individuals normal control as well as normal sensation are lost. The desire to urinate may be felt when there is little urine in the bladder, and urination may occur without warning or control. By blocking the effect of acetyl-choline on the muscle cells, tolterodine slows the build-up of pressure in the bladder, reduces the sensation to urinate, and prevents uncontrolled urination. The FDA approved tolterodine in 1998. An extended release form of tolterodine, (Detrol LA) was approved by the FDA in 2001.

PREPARATIONS: Tolterodine tablets: 1mg and 2mg. Long acting tolterodine capsules: 2mg and 4 mg.

STORAGE: Tablets and capsules should be stored at room temperature, 15-30°C (59-86°F).

PRESCRIBED FOR: Tolterodine is used to treat uncontrollable urination due to what is often referred to as an "overactive" bladder. Symptoms include the need to urinate frequently, an urge to urinate immediately, and an inability to control urine release (urinary incontinence).

DOSING: Tolterodine usually is taken twice daily. The starting dose is 2mg twice daily. With the long-acting tolterodine, the starting dose is 4mg daily, and may be reduced to 2mg if the larger dose is not tolerated. The dose may need to be reduced for patients who have impaired function of the liver or kidneys. Caution is recommended for patients with narrow-angle glaucoma, obstruction to the flow of urine, or poor emptying of the stomach since these medical conditions may worsen with tolterodine administration.

DRUG INTERACTIONS: Tolterodine follows a specific path through the liver in order to be eliminated from the body. Drugs that block this path may slow the elimination of tolterodine, raise tolterodine blood levels, and lead to side effects. No formal studies have been conducted showing such interactions, however. The list of drugs that might possibly interfere with the elimination of tolterodine includes is erythromycin, clarithromycin (Biaxin), ketoconazole (Nizoral), itraconazole (Sporanox), and miconazole (Monistat, Micatin). The dose of tolterodine should be reduced to 1mg twice daily if taken with any of these drugs.

PREGNANCY: At doses much greater than those used in humans, tolterodine causes fetal abnormalities in animals. There are no studies with tolterodine in pregnant women. Therefore, tolterodine should only be given to pregnant women if the benefits are felt to outweigh the potential risks.

NURSING MOTHERS: Tolterodine is secreted into breast milk in animals; however, it is not known if tolterodine is secreted into the breast milk of women. Therefore, its use is not recommended in nursing mothers.

SIDE EFFECTS: The most common side effects seen while taking tolterodine are dry mouth, dry eyes, headache, upset stomach and constipation. Tolterodine also may cause blurred vision.