Detrol is available in capsule form with strengths of 2 mg ER (Extended Release), 2 mg SR (Sustained Release), 2 mg XL (Extra Long Release), and 4 mg of each release type. These capsules are produced by reputed pharmaceutical manufacturers. The active ingredient, Tolterodine, helps manage the symptoms of an overactive bladder, which can include a sudden urge to urinate or more frequent urination than usual. Detrol is also marketed under various brand names such as Terol LA, Roliten, Roliflo, Tamlet, and Torq.