Described are compositions comprising a muscarinic receptor antagonist and an N-acylated heterocycle derivative having affinity for serotonergic receptors, and enantiomers, diastereoisomers, N-oxides, polymorphs, solvates and pharmaceutically acceptable salts thereof. The combination of a muscarinic receptor antagonist and an N-acylated heterocycle, or an enantiomer, diastereoisomer, N-oxide, polymorph, solvate or pharmaceutically acceptable salt thereof, is useful in the treatment of patients with neuromuscular dysfunction of the lower urinary tract and diseases related to 5-HT1A receptors.