The present invention relates to new derivatives of pyrrole of formula: ##STR1## in which: R.sub.1 represents an atom of hydrogen, a lower alkyl group, a phenyl radical or a pyridyl-2 radical,R.sub.2 represents an atom of hydrogen or a lower alkyl radicalR.sub.3 and R.sub.4 represent a lower alkyl or cycloalkyl radical or the radical ##STR2## is a heterocyclic amine radical, and n is equal to 2 or 3;The invention concerns drugs having an antiarrhythmic activity and an activity as blood platelet anti-aggregant, containing said derivatives.