Additional Study Information: The purpose of this study is to determine whether the drug, bethanechol, could potentially be used in combination with chemotherapy regimen gemcitabine and nab-paclitaxel and surgery to decrease the chance of the cancer coming back after it is removed. Animal models have shown that treatment with bethanechol can inhibit cancer growth and spread. The chemotherapy regimen nab-paclitaxel for use in combination with gemcitabine to treat patients with metastatic pancreatic cancer is FDA-approved. Although bethanechol is FDA-approved, in this study its use is experimental. The aim of the study is to show that the medication is easy to tolerate and that it shows signs of slowing cancer cell growth.