Medicaments

The invention relates to the use of compounds of the general formula (I)whereinR1 represents a hydrogen atom or a C1-10 alkyl, C3-7 cycloalkyl, C3-7 cycloalkyl-(C1-4)alkyl, C3-6 alkenyl, C3-10 alkynyl, phenyl or phenyl-C1-3 alkyl group; and one of the groups represented by R2, R3 and R4 is a hydrogen atom or a C1-6 alkyl, C3-7cycloalkyl, C2-6 alkenyl or phenyl-C1-3 alkyl group and each of the other two groups, which may be the same or different, represents a hydrogen atom or a C1-6 alkyl group;and physiologically acceptable salts and solvates thereof, for the relief of nausea and vomiting and/or the promotion of gastric emptying and for the manufacture of a medicament for this purpose.