Do diuretics have an effect on calcium excretion?

Do diuretics have an effect on calcium excretion?_6.jpg

Yes. Thiazide diuretics increase serum calcium concentrations by promoting tubular resorption of calcium. They are contraindicated in acute hypercalcemic states. Thiazides are useful in preventing calcium-containing renal calculi or urolithiasis since they diminish the calcium concentration of urine. Thiazides may cause hypercalcemia in patients with renal insufficiency who take calcium-containing medications or vitamin D.

What complications of diuretic use are potentially life-threatening?

The thiazide diuretics and loop diuretics can cause pancreatitis. With loop diuretics, the mechanism is unknown but may involve excessive pancreatic secretion because of amplified secretin release. With thiazides, the inciting factor is thought to be hypercalcemia caused by the medication. Diuretic-induced pancreatitis is uncommon.

In patients prone to ventricular arrhythmias, such as those with congestive heart failure, hypokalemia may help precipitate ventricular tachycardia or ventricular fibrillation. This is especially important when digoxin is being used concurrently.

Diabetes insipidus is characterized by an inappropriate increase in urine production. Why are diuretics used to treat this disorder?

Thiazide drugs, by inducing mild sodium and extracellular volume depletion, invoke a compensatory increase in proximal tubule sodium and water resorption. The amount of filtrate delivered to the distal diluting segment is thereby reduced and urine output is diminished.

A patient is vacationing in Colorado to ski. On prior trips, he experienced headaches, nausea, and insommia. His doctors advised him to take a “water pill” prior to skiing, but he forgot the medication and cannot remember its name. What medication would you prescribe?

This patient’s history and symptoms are consistent with high-altitude sickness. Acetazolamide, a carbonic anhydrase inhibitor, has been used to treat this condition. Its mechanism of action is the induction of a metabolic acidosis which stimulates the respiratory drive and diminishes altitude-induced hypoxemia. It cannot, however, be relied upon to prevent the life-threatening complications of pulmonary or cerebral edema or reduce the incidence of retinal hemorrhage. Descent is the only effective treatment for these problems.

Do diuretics have an effect on calcium excretion?_6.jpg

Leave a Reply