Use of compound of formula (I), wherein, is, or, and wherein the symbols are as defined, or a pharmaceutically-acceptable and -cleavable ester, or acid addition salt thereof, for the preparation of a medicament for promoting the release of parathyroid hormone, e.g. for preventing or treating bone conditions which are associated with increased calcium depletion or resorption or in which stimulation of bone formation and calcium fixation in the bone is desirable.