Final answer:
A nurse should primarily assess for sudden weight gain of 2 pounds or more when monitoring a patient on amlodipine, as this could indicate fluid retention and potential worsening of heart failure.
Step-by-step explanation:
The client is taking amlodipine (Norvasc), which is a medication used to treat high blood pressure, angina (chest pain), and certain types of cardiac arrhythmias (abnormal heart rhythms). A primary assessment for the nurse when monitoring a client on amlodipine would be to watch for signs of fluid retention, which can manifest as a sudden weight gain of 2 pounds or more. This could indicate a worsening of heart failure, a potential complication of heart conditions being treated with amlodipine.
Monitoring for sudden weight gain is more relevant than changes in INR levels, which are more directly associated with anticoagulant medications rather than amlodipine. While electrolyte imbalances such as hypokalemia and hypernatremia could be a concern with some cardiovascular drugs, they are not the primary effect of amlodipine. Also, a sudden weight loss of 5 pounds or more would not be the primary concern with amlodipine usage unless it is associated with other symptoms that could indicate a severe adverse reaction.