(R)-Enantiomers of quaternary ammonium salts of general formula (I) are described: ##STR1##

where R, R₁, R₂, R₃, X and Z are as defined in the description. The process for their preparation and pharmaceutical preparations thereof are also described. The quaternary salts of the invention are useful in the inhibition of chemotaxis of neutrophils and monocytes induced by the fraction C5a of the complement and are used in the treatment of psoriasis, pemphigus and pemphigoid, rheumatoid arthritis, intestinal chronic inflammatory pathologies including ulcerative colitis, acute respiratory distress syndrome, idiopathic fibrosis, cystic fibrosis, chronic obstructive pulmonary disease and glomerulonephritis. The compounds of the invention are advantageously used in the prevention and the treatment of injury caused by ischemia and reperfusion.