A nurse is caring for a client who has diabetes mellitus and is taking pioglitazone. The nurse should plan to monitor the client for which of the following adverse effects?

Amlodipine is a long-acting dihydropyridine calcium channel blockerthat inhibits the transmembrane influx of calcium ions into vascular smooth muscle. It primarily causes systemic vasodilation, effectively reducing peripheral vascular resistance and lowering arterial blood pressure in hypertensive patients.

Rationale:

A.Oxygen saturation is a measure of hemoglobin oxygen binding and is not directly affected by the administration of calcium channel blockers like amlodipine. While respiratory assessment is part of general nursing care, it is not the priority parameter for a medication that targets vascular resistance. Amlodipine does not interfere with pulmonary gas exchange or the oxygen-carrying capacity of the blood.

B.Heart rate is a critical assessment for non-dihydropyridines like diltiazem, but amlodipine has minimal effect on the sinoatrial or atrioventricular nodes. Because amlodipine is vascular-selective, it does not typically cause the bradycardia associated with other calcium channel blockers. While reflexive tachycardia can occur due to vasodilation, blood pressure remains the most vital parameter to assess prior to dosing this specific agent.

C.Blood pressure must be assessed before administering amlodipine because its primary pharmacological effect is to lower systemic blood pressure through vasodilation. Giving the medication to a patient who is already hypotensive could lead to severe cardiovascular compromise, dizziness, or syncope. The nurse must ensure the client's pressure is within the safe parameters established by the provider to prevent iatrogenic hypotension.

D.Respiratory rate is not influenced by amlodipine, as the drug does not act on the central nervous system respiratory centers or the musculature of the diaphragm. Unlike opioids or certain sedatives, amlodipine does not carry a risk of respiratory depression. Monitoring the breathing rate, while standard, does not provide information relevant to the safety or hemodynamic impact of this antihypertensive medication.

Morphine is an opioid agonistthat binds to mu-opioid receptors in the central nervous system to provide potent analgesia. Beyond pain relief, it exerts a depressant effecton the respiratory center and the autonomic nervous system, necessitating continuous monitoring of the patient's level of consciousness and hemodynamic stability.

Rationale:

A.Tachycardia is not a typical adverse effect of morphine; in fact, opioids tend to cause a decrease in heart rate or have no significant effect on it. Morphine reduces sympathetic outflow, which is more likely to result in bradycardia or a stable heart rate. The presence of tachycardia in a patient on a PCA pump might actually indicate inadequately controlled pain or a different underlying complication.

B.Sedation is a common and significant adverse effect of morphine that often precedes respiratory depression in patients using a PCA pump. The nurse must use a standardized scale to assess the client's arousal level, as excessive sleepiness indicates the drug is accumulating to potentially toxic levels. Monitoring for sedation allows the nurse to intervene early by adjusting the dose before life-threatening complications occur.

C.Hypotension occurs with morphine administration due to peripheral vasodilation and the release of histamine, which lowers systemic vascular resistance. This is particularly common when the drug is administered intravenously or in large doses via a PCA pump. The nurse must monitor blood pressure regularly and instruct the client to change positions slowly to prevent orthostatic hypotension and potential falls during therapy.

D.Hyperthermia is not an adverse effect associated with opioid analgesics like morphine. Morphine does not interfere with the thermoregulatory center in the hypothalamus in a way that would cause an elevated body temperature. If a patient receiving morphine develops a fever, the nurse should investigate other causes, such as an underlying infection or an inflammatory process, rather than attributing it to the medication.

E.Bradypnea, or an abnormally slow respiratory rate, is one of the most dangerous adverse effects of morphine because it directly depresses the brainstem respiratory centers. The nurse must count the client's respirations frequently and be prepared to administer naloxone if the rate falls below 8 to 10 breaths per minute. Bradypnea can lead to hypercapnia and respiratory arrest, making it a critical focus of PCA monitoring.