Desfesoterodine is an active metabolite of antimuscarinic drugs for the treatment of overactive bladder fesoterodine and tolterodine. In contrast to the cytochrome P450 (CYP) 2D6-mediated metabolism of tolterodine, desfesoterodine formation from fesoterodine occurs via ubiquitous nonspecific esterases. Serum levels of the desfesoterodine in humans are generally comparable to those of tolterodine following oral administration of the parent compound. The pharmacological in vitro and in vivo profiles of desfesoterodine are almost identical to those of tolterodin. The potent antimuscarinic action of desfesoterodine on the urinary bladder was confirmed in the in vivo studies and, like tolterodine, desfesoterodine was significantly more potent in inhibiting bladder contractions than salivation in the anaesthetised cat. Desfesoterodine is more potent than tolterodine in vivo. The apparent difference in potency in vivo might be explained by the degree of serum protein binding of the two compounds. The fraction of unbound drug in serum is larger for desfesoterodine than for tolterodine. Desfesoterodine may contribute to the therapeutical action of tolterodine.

Tolterodine is competitive muscarinic receptors M3 and M2 antagonist. It was sold under trade names detrol for the treatment of overactive bladder with symptoms of urge urinary incontinence. Both urinary bladder contraction and salivation are mediated via cholinergic muscarinic receptors. After oral administration, tolterodine is metabolized in the liver, resulting in the formation of the 5-hydroxymethyl derivative, a major pharmacologically active metabolite. The 5-hydroxymethyl metabolite, which exhibits an antimuscarinic activity similar to that of tolterodine, contributes significantly to the therapeutic effect. Both tolterodine and the 5-hydroxymethyl metabolite exhibit a high specificity for muscarinic receptors, since both show negligible activity and affinity for other neurotransmitter receptors and other potential cellular targets, such as calcium channels. Tolterodine has a pronounced effect on bladder function. The main effects of tolterodine at 1 and 5 hours were an increase in residual urine, reflecting an incomplete emptying of the bladder, and a decrease in detrusor pressure. These findings are consistent with an antimuscarinic action on the lower urinary tract.

Tartaric acid is found in many plants such as grapes, tamarinds, pineapples, mulberries and so on. Wine lees (called mud in the US), the sediment collected during the fermentation of grapes, contains potassium bitartrate (potassium hydrogen tartrate) as its major component. L-(+)-tartaric acid is an enantiomer of tartaric acid. Twenty five years before the tetrahedral structure for carbon was proposed in 1874 to explain the optical activity and other properties of organic compounds, Louis Pasteur discovered the existence of enantiomerism in tartaric acid. L-(+)-tartaric acid is widely used in food and beverage as acidity regulator with E number E334.