Indeed Pirenzepine[1] is a muscarinic receptor antagonists. “The muscarinic receptor is a protein involved in the transmission of signals through certain parts of the nervous system, and muscarinic receptor antagonists work to prevent this transmission from occurring.“[2] I could imagine that a let’s say relaxed nervous system recovers better.

1. https://en.m.wikipedia.org/wiki/Pirenzepine 2. https://en.m.wikipedia.org/wiki/Muscarinic_receptor_antagoni...