The invention relates to the co-administration in human or veterinary medicine of 1,2,3,9-tetrahydro-9-methyl-3-[(2-methyl-1H-imidazol-1-yl)methyl]-4H-carbazol-4-one or a physiologically acceptable salt or solvate thereof and dexamethasone or a physiologically acceptable salt or ester thereof. The two active ingredients, which may be administered separately either simultaneously or sequentially, or may be combined in a single pharmaceutical preparation, are useful in the relief and/or prevention of nausea and vomiting.