Which location is the area where the highest percentage of sodium and water are resorbed back into the bloodstream?

Correct Answer: B

Rationale: The area where the highest percentage of sodium and water are reabsorbed back into the bloodstream is the proximal tubule. In the nephron, the proximal tubule is responsible for reabsorbing approximately 65-70% of filtered sodium and water. This reabsorption is crucial for maintaining the body's electrolyte balance and blood volume. The proximal tubule is lined with specialized cells that actively transport sodium ions out of the tubular fluid, creating an osmotic gradient that allows for passive reabsorption of water. This efficient reabsorption process helps to ensure that essential substances are conserved while waste products are excreted in the urine.

Correct Answer: B

Rationale: Lithium levels rise with drugs reducing renal clearance or altering metabolism. St John's wort induces CYP enzymes, potentially lowering lithium (not renally metabolized). Ibuprofen, an NSAID, reduces renal lithium excretion by inhibiting prostaglandins, increasing plasma levels, a well-known interaction. Phenytoin induces metabolism but doesn't affect lithium's renal clearance. Haloperidol and sertraline have minimal pharmacokinetic impact on lithium. Ibuprofen's effect necessitates monitoring, as elevated lithium risks toxicity (e.g., tremor, confusion), critical in bipolar management.

Correct Answer: C

Rationale: The correct instruction for the nurse to give the client regarding discontinuing a beta blocker is that it should NOT be abruptly stopped; the dose should be tapered down. Suddenly stopping a beta blocker can lead to rebound hypertension, angina, and even heart attack in some cases. Tapering down the dose helps the body adjust gradually and reduces the risk of adverse effects associated with abrupt discontinuation. It is important for the client to follow the healthcare provider's guidance on how to safely decrease the dose of the beta blocker.

Correct Answer: D

Rationale: The loading dose of a drug required to reach an initial target blood concentration is based on the volume of distribution (Vd) of the drug. The volume of distribution represents the theoretical volume that would be necessary to contain the total amount of the administered drug at the same concentration as in the blood plasma. The loading dose is calculated by multiplying the target blood concentration by the volume of distribution of the drug. This initial dose helps to rapidly achieve the desired drug concentration in the body, especially when a drug has a long half-life or when steady-state levels need to be reached more quickly. Understanding the volume of distribution of a drug is crucial in dosage calculation to ensure therapeutic efficacy and avoid potential toxicity.

Correct Answer: C

Rationale: Cholestyramine (Questran) is a bile acid sequestrant used to lower cholesterol levels in the blood. To prevent clumping and sticking to the glass when mixing the powder, the nurse will suggest mixing the powder with food or fruit, or at least 4 to 6 ounces of fluid. This method helps to evenly disperse the powder and prevent clumping, making it easier for the patient to consume the medication. Mixing the powder with a carbonated soda drink (choice A) may not be suitable as the effervescence of the soda could affect the medication's stability. Adding the powder to any liquid and stirring vigorously (choice B) may not dissolve the powder effectively. Taking the powder dry on a spoon followed by a glass of water (choice E) may be difficult for the patient to swallow and may not distribute the medication evenly. Mixing with food or fluid provides a more palatable and effective method for administering Questr

Correct Answer: D

Rationale: Metformin is a medication commonly used to treat type 2 diabetes. It exerts its action through multiple mechanisms, as outlined below:

Correct Answer: D

Rationale: Sildenafil (Viagra), a phosphodiesterase-5 inhibitor, enhances penile blood flow by increasing cyclic GMP, directly treating erectile dysfunction (ED) and is the standard first-line therapy. Leuprolide, a GnRH agonist, suppresses testosterone for prostate cancer, potentially worsening ED. Finasteride, for benign prostatic hyperplasia (BPH), reduces prostate size but may cause ED as a side effect, not treat it. Tamsulosin, an alpha-blocker for BPH, improves urinary flow but isn't indicated for ED and can lower blood pressure. Sildenafil's targeted action on vascular mechanisms in ED distinguishes it, offering rapid efficacy and a well-established safety profile for this condition.

Correct Answer: D

Rationale: When administering Phenytoin, it is important to monitor all of the listed parameters - behavior, therapeutic blood levels, and for Steven Johnson syndrome.

Correct Answer: B

Rationale: The common side effects of amitriptyline (Elavil) include constipation and dry mouth. Increasing fluid intake can help alleviate these symptoms. Adequate hydration can aid in promoting bowel regularity and relieving dry mouth. It is important for the nurse to give the patient instructions to increase their fluid intake to manage these side effects rather than immediately discontinuing the medication or requesting a change in antidepressants. If the constipation and dry mouth persist or worsen despite increasing fluid intake, then the provider may need to be notified for further evaluation and management.