A client calls the clinic and tells the nurse that she has missed taking several of her contraceptive pills during the current cycle. What is the best instruction for the nurse to give the client?

Correct Answer: D

Rationale: Missing oral contraceptive pills reduces their efficacy, increasing pregnancy risk. If several pills are missed , the hormonal protection is compromised, requiring an alternative method (e.g., condoms) for the cycle's remainder to prevent conception. Immediate pregnancy testing assesses outcome, not prevention. Suggesting a new method addresses future planning, not current risk. Choice C underestimates the risk, as even fewer than three missed pills can disrupt efficacy, depending on timing. The nurse's best instruction (D) ensures immediate protection, aligning with contraceptive guidelines for missed doses, prioritizing safety and efficacy.

Correct Answer: B

Rationale: Digitalis has a negative chronotropic effect, meaning it slows down the heart rate. This can be evident in a patient by observing a decrease in their heart rate. Chronotropy refers to the heart rate or rhythm of the heart. Digitalis works by inhibiting the sodium-potassium pump in the heart muscle cells, leading to an increase in intracellular calcium levels. This results in a decreased heart rate and improved contractility of the heart muscle. Therefore, a decreased heart rate is the expected effect when a patient is receiving intravenous digitalis.

Correct Answer: B

Rationale: Spironolactone, a potassium-sparing diuretic, treats hypertension by blocking aldosterone, reducing sodium reabsorption while retaining potassium . This risks hyperkalemia (>5.0 mEq/L), causing arrhythmias or muscle weakness, especially in renal impairment. Monitoring potassium closely ensures early detection, critical for safety. Sodium may drop mildly but isn't the primary concern. Calcium and magnesium aren't directly affected. Potassium's elevation aligns with spironolactone's mechanism, distinct from other diuretics that deplete it, making it the priority electrolyte. Regular checks (e.g., serum levels) prevent toxicity, particularly in hypertension where cardiac stability is key, thus B is the nurse's focus for vigilant monitoring and timely intervention.

Correct Answer: A

Rationale: Low potassium levels, known as hypokalemia, can increase the toxicity of cardiac glycosides such as digoxin. These drugs work by inhibiting the sodium-potassium pump in cardiac cells, leading to increased intracellular sodium levels. When potassium levels are low, it can worsen this effect and lead to increased risk of cardiac dysrhythmias and toxicity from the drug. Potassium levels should be carefully monitored in patients taking cardiac glycosides to prevent complications. A potassium level of 2.8 mEq/L is considered significantly low and would pose an increased risk of toxicity with cardiac glycoside use.

Correct Answer: A

Rationale: The therapeutic and adverse effects associated with these drugs are related to their adrenergic-receptor-site specificity; that is, the ability to react with specific adrenergic receptor sites without activating them, thus preventing the typical manifestations of sympathetic nervous system (SNS) activation. By occupying the adrenergic receptor site, they prevent norepinephrine released from the nerve terminal or from the adrenal medulla from activating the receptor, thus blocking the SNS effects. The nurse should understand the mechanism of action of adrenergic blocking agents to ensure safe and effective administration.