Which finding indicates to the nurse that demeclocycline is effective for a patient with a syndrome of inappropriate antidiuretic hormone (SIADH)?
A.
Urine-specific gravity is increased.
B.
Patient’s weight is increased.
C.
Peripheral edema is decreased.
D.
Patient’s urinary output is increased.
The correct answer and Explanation is :
The correct answer is D. Patient’s urinary output is increased.
Explanation:
Demeclocycline is a tetracycline antibiotic that is often used off-label to treat the syndrome of inappropriate antidiuretic hormone secretion (SIADH). SIADH leads to excessive secretion of antidiuretic hormone (ADH), resulting in water retention, dilutional hyponatremia, and concentrated urine. The goal of treatment with demeclocycline is to promote free water excretion by the kidneys, effectively counteracting the effects of excess ADH.
When demeclocycline is effective, one of the primary indicators is an increase in urinary output. This occurs because the medication reduces the kidney’s responsiveness to ADH, allowing the kidneys to excrete more dilute urine and consequently increase the total volume of urine produced. Increased urinary output helps correct the fluid imbalance caused by SIADH and can assist in normalizing serum sodium levels.
In contrast, the other options provided do not indicate the effectiveness of demeclocycline in treating SIADH:
- A. Urine-specific gravity is increased: This would indicate concentrated urine, which is contrary to the expected effect of demeclocycline. Effective treatment should lead to a lower urine-specific gravity due to dilution.
- B. Patient’s weight is increased: Weight gain in this context typically reflects fluid retention, which would suggest that SIADH is still active and that demeclocycline is not effective.
- C. Peripheral edema is decreased: While edema can occur in cases of fluid overload, its decrease may not directly correlate with the effectiveness of demeclocycline in managing SIADH.
In summary, the increase in urinary output is a crucial indicator that demeclocycline is functioning as intended by promoting the excretion of excess water, thereby helping to manage the complications associated with SIADH.