Effects of the peripherally acting μ-opioid receptor antagonist methylnaltrexone on acute pancreatitis severity: study protocol for a multicentre double-blind randomised placebo-co... oleh Cecilie Siggaard Knoph, Mathias Ellgaard Cook, Camilla Ann Fjelsted, Srdan Novovic, Michael Bau Mortensen, Liv Bjerre Juul Nielsen, Mark Berner Hansen, Jens Brøndum Frøkjær, Søren Schou Olesen, Asbjørn Mohr Drewes