[Are thiazide diuretics ineffective with a glomerular filtration rate lower than 50 ml/min?]

Many treatment guidelines do not recommend the use of thiazide diuretics or thiazide-like diuretics in patients with impaired kidney function. The rationale is a presumed lack of efficacy of these diuretics in cases of a reduced glomerular filtration rate (GFR); however, this paradigm could not be verified in recent studies. Thiazide diuretics and thiazide-like diuretics are also effective in patients with substantially reduced GFR, which pertains to natriuresis, correction of volume overload and lowering of blood pressure; however, in patients with chronic kidney disease loop diuretics can control volume overload more rapidly. Particularly effective is the combination of loop diuretics with thiazide diuretics or thiazide-like diuretics in patients with markedly limited GFR. Therefore, thiazide diuretics and thiazide-like diuretics should also be prescribed even for patients with higher grade impairments of kidney function (chronic kidney disease in stages 3-5), except for anuric patients where they are ineffective.