A patient is in the intensive care unit because of an acute myocardial infarction. He is experiencing severe ventricular dysrhythmias. The nurse will prepare to give which drug of choice for this dysrhythmia?

Correct Answer: C

Rationale: Amiodarone is the drug of choice for treating severe ventricular dysrhythmias, such as those seen in patients with acute myocardial infarction. It is effective in treating both ventricular tachycardia and ventricular fibrillation. Amiodarone works by prolonging the action potential duration and refractory period in cardiac tissues, thereby helping to stabilize the heart's electrical activity. Diltiazem and Verapamil are calcium channel blockers that are not typically used for treating ventricular dysrhythmias. Adenosine is primarily used for treating supraventricular tachycardias.

Correct Answer: C

Rationale: Senna is a stimulant laxative commonly used to treat constipation. Its effectiveness is primarily evaluated based on the production of soft, well-formed bowel movements. Senna works by stimulating the muscles in the intestines, promoting bowel movements and easing constipation. It is not typically used for reducing GI pain and irritation, healing ulcers, or preventing nausea and vomiting. Therefore, the evaluation of medication effectiveness of senna is primarily based on achieving soft, formed bowel movements in patients with constipation.

Correct Answer: C

Rationale: Digoxin is a medication commonly used to treat heart failure and certain types of irregular heartbeats. Its therapeutic effect includes increasing cardiac output, which helps improve the function of the heart. Digoxin also has the ability to slow down the heart rate, making it particularly beneficial for patients with conditions like atrial fibrillation or atrial flutter. Therefore, among the options provided, Digoxin is the drug that has a therapeutic effect of increasing cardiac output and slowing heart rate.

Correct Answer: C

Rationale: Senna is a natural laxative commonly used to relieve constipation. Its primary mechanism of action is to stimulate the muscles in the intestines, leading to increased contractions and bowel movements. The evaluation of medication effectiveness for senna would typically focus on its ability to promote bowel movements and alleviate constipation. This would manifest as patients experiencing solid, formed bowel movements after taking senna. The options of decreased GI pain and irritation, healing of ulcers, and prevention of nausea and vomiting are not the primary expected outcomes when evaluating the effectiveness of senna as a medication for constipation.

Correct Answer: D

Rationale: When giving the drug Phenytoin, monitoring urinary pH is important because Phenytoin is known to be excreted by the kidneys. Changes in urinary pH can affect the concentration of Phenytoin in the body. Alkaline urine can increase the excretion of Phenytoin, potentially leading to subtherapeutic levels, while acidic urine can decrease excretion, potentially leading to toxic levels of the drug. Therefore, monitoring urinary pH helps ensure that Phenytoin levels are within the therapeutic range, minimizing the risk of either subtherapeutic or toxic effects. Monitoring for signs of toxicity, such as ataxia, nystagmus, and confusion, is also essential when administering Phenytoin.