In some cases diabetes insipidus may be induced by taking medications. In this article we report the case of a 58-year-old man with manifest polyuria induced by colchicine administered because of a gout attack. Interestingly, similar symptoms were observed 6 years earlier after treatment with gentamycin. In the described state of the examined patient early detection of the disease, colchicine withdrawal and temporary amiloride (and indometacin) administration led to a full normalisation of the patient's clinical status. A similar reaction to two different drugs responsible for only a small percentage of iatrogenic diabetes insipidus suggests that some patients may exhibit a general "hypersensitivity" to the development of a drug-induced vasopressin resistance and that patients with the history of iatrogenic diabetes insipidus should not be treated or should be treated cautiously with other drugs known to induce vasopressin-resistant polyuria.