**5.1.3 Pelvic floor muscle training (PFMT)**

PFMT involves exercises designed to improve the function of the pelvic floor muscles. Using PFMT to treat OAB is based on the theory that contraction of the levator ani muscles can reflexively inhibit contraction of the detrusor muscle. PFMT is defined as any program of repeated voluntary pelvic floor muscle contractions (VPFMC) taught by a trained healthcare professional. (Wilson et al., 2005) Patients are taught to squeeze the pelvic floor with three sets of 8 to 12 slow velocity contractions held for six to eight seconds each. These exercises should be performed at least three or four times a week and continued for at least 15 to 20 weeks. (Hay-Smith et al., 2009)

There is increasing evidence to support the use of PFMT for OAB. Patients with detrusor overactivity who completed a PFMT program experienced a clinically and statistically significant reduction in daily UI episodes. (Ba & Berghmans, 2000 and Nygaard et al., 1996) These investigators also reported a significant decrease in urge score. This urge score was

Diagnosis and Treatment of Overactive Bladder 173

During this phase, there is normally no parasympathetic input to the LUT. (Abrams &

A recent Cochrane review assessed the various anticholinergics available for the treatment of OAB in adults. The conclusions of this review were when the prescribing choice is between oral immediate-release oxybutynin and tolterodine, tolterodine might be preferred due to a reduced risk of dry mouth. In addition, they concluded that if extended-release preparations of either drug are available, they would be preferred to the immediate-release preparations because of the decreased risk of dry mouth and better compliance. There were insufficient data from trials of other anticholinergic drugs to draw any conclusions. (Hay-Smith et al., 2005) The most commonly prescribed anticholinergic drugs and their dosages in the treatment of OAB are listed in Table 1.

As mentioned above, oxybutynin was the first anticholinergic widely used for the treatment of OAB. It is an anticholinergic agent that has antimuscarinic, antispasmodic, and potential local anesthetic effects. Oxybutynin has been shown to have a high affinity for the M1 & M3 receptors and much less affinity for the M2 receptor. (Hughes et al., 1992 and Nilvebrant & Sparf, 1986) It is available in immediate release (IR), extended release (ER), transdermal patch and topical gel formulations. In general, the efficacy is similar for all formulations. The initial dosage for IR is 2.5 mg two to three times daily, followed by titration as needed up to 20 mg/day in divided doses. The ER formulation is started at 5 mg once daily and titrated

The transdermal patch (equivalent to 3.9 mg/day) applied to the abdomen, hip, or buttock is changed twice a week. The topical 10% gel is applied as 1 gm (approximately 1 mL) daily to the thigh, abdomen, upper arm, or shoulder. Currently, oxybutynin IR and ER are available as generic formulation in the United States. Oxybutynin IR is associated with high rates of anticholinergic adverse effects. Dry mouth is a particularly bothersome side effect for patients that can limit therapy with oxybutynin IR. This side affect is less frequent with the ER and transdermal preparations (Anderson et al., 1999; Davila et al., 2001; Versi et al., 2000) Irritation and pruritus at the application site has been reported in approximately 15 percent of patients using transdermal oxybutynin and 5 percent using the topical gel.

Tolterodine has been shown to be a competitive muscarinic receptor antagonist with some selectivity for bladder muscarinic receptors [59]. It is available in immediate- and extendedrelease forms. Tolterodine is administered at 1 to 2 mg twice a day for the IR preparation or 2 to 4 mg per day using the ER preparation. It has similar efficacy when compared to other antimuscarinics. Both formulations have shown efficacy for symptoms of OAB in a large

One of the few "head to head" studies between anticholinergic drugs was The STAR trial. In this study the investigators directly compared solifenacin (discussed below) at a flexible 5 or 10 mg once daily dose with tolterodine extended release 4 mg once daily in a randomized

Andersson, 2007)

(Shaw & Burrows, 2011)

up to 20 to 30 mg once daily.

(Dmochowski et al., 2002)

study population (Choo et al., 2008).

**5.2.1.2 Tolterodine** 

**5.2.1.1 Oxybutynin** 

defined as the frequency of leakage (0 *=* never to 4 *=* always) during 9 activities that can trigger urge incontinence.
