Posted by: Helen Caley13 JAN 2014
I shadowed a pharmacist on a ward round where we saw apatient who had a low sodium blood level. He had also had a fall and was weak.A scan determined that there was no brain damage so it was deemed safe toprescribe low molecular weight heparin. This prevents the formation of bloodclots and if the patient had a bleed on the brain this would not have beenappropriate, as it would be important for the blood to clot to stop the bleed. Iwas set a task of trying to find out what could be wrong with the patient frombeing told to research SIADH. I discovered that SIADH is syndrome ofinappropriate antidiuretic hormone secretion. This commonly leads tohyponatraemia (low sodium) and fluid overload, i.e. the blood is diluted. Thetreatment for this condition is often fluid restriction and diuretics todecrease the reabsorption of fluid in the kidney. The patient was given demeclocyclinewhich is a tetracycline antibiotic, however, it is also widely used fortreating hyponatraemia due to SIADH. It was also important to treat theunderlying condition which caused the SIADH. In this case it was due to thepatient taking sertraline for paranoia. It was paramount that the paranoia wasstill treated as it was severe, and the doctors asked the pharmacist whethermirtazapine would be a suitable alternative. It was crucial that this would notexacerbate the hyponatraemia.