The efficacy of multiple muscarinic antagonists, ranging from non-selective on-market drugs such as atropine, cyclopentolate, glycopyrrolate and oxybutynin to M1R selective (pirenzepine) and M1R specific (MT7) agents has been determined using key indices of peripheral neuropathy that reflect structural, functional, and metabolic disorders [130]. The gene discussed is CHRM1; the disease is peripheral neuropathy.