Posterior pituitary replacement is best achieved using an enzyme-resistant analogue of ADH, which itself has a short duration of action and may cause intense vasoconstriction. For this reason, the drug desmopressin is given (10-20┬╡g once or twice daily, intranasally), since it is devoid of vasoconstrictor actions at therapeutic doses. Recently, it has become clear that this drug is also effective orally (100┬╡g three times daily). In partial ADH deficiency, a reduction in urine volume can be achieved by using chlorpropramide, which increases the sensitivity of the renal tubules to endogenous ADH. This can, however, cause hypoglycaemia, particularly in the elderly, who should be warned to eat before retiring to bed.
