Intended for healthcare professionals
Rapid response to:
In their excellent Practice Pointer ‘Diabetes Insipidus’, there are 2 important areas that Levy and colleagues might have usefully included.
Firstly, whilst a ‘diabetes insipidus card and booklet to carry with them’ may be empowering for many patients, the use of modern technology such as ICE [in case of emergency] on mobile phones is an additional or alternative modality that also has an important role to play in patient safety.
Secondly, pregnancy can be a particularly challenging time to diagnose and manage Diabetes Insipidus. Physiological changes of normal pregnancy lead to thirst and increased fluid intake as well as increased urine output, so the clinical history may be less clear, although it is unusual for a healthy pregnant woman to drink more than 3litres of water daily.
Placental vasopressinase increases the metabolism of antidiuretic hormone, and can result in gestational Diabetes Insipidus especially in women with previous subclinical disease and or altered liver metabolism [with reduced antidiuretic hormone(ADH) breakdown] as for example in pre eclampsia, HELLP [haemolysis, elevated liver enzymes, low platelets] syndrome and acute fatty liver of pregnancy: treatment is with Desmopressin and delivery, as removal of the placenta allows ADH levels to begin to return to normal.
For pregnant women already diagnosed with Diabetes Insipidus, enhanced antenatal, intrapartum and immediate postnatal care is required. Desmopressin dose increment should be anticipated in pregnancy due to accelerated metabolism of endogenous ADH [as Desmopressin has a different N terminal to ADH it is not metabolised by vasopressinase], with reduction again after birth; it has no oxytocin-like properties and is safe in pregnancy and breastfeeding.
Competing interests: No competing interests