An older adult client is being discharged after a myocardial infarction (MI) and receives a new prescription for atenolol. Which instruction is most important for the nurse to include in this client's teaching plan?

A. Excessive bruising: While statins can rarely affect platelet function, leading to bruising, this is not commonly associated with elevated creatine kinase (CK) levels. Bruising is more indicative of coagulation issues rather than muscle injury.

B. Muscle tenderness: Elevated CK levels in a client taking atorvastatin suggest muscle injury, such as myopathy or rhabdomyolysis. Muscle tenderness, pain, or weakness are hallmark symptoms of these conditions. Prompt assessment is crucial, as continued statin use in the presence of muscle damage can lead to serious complications, including kidney failure .

C. Nausea and vomiting: These symptoms are nonspecific and can result from various causes. While they may occur in rhabdomyolysis, they are not primary indicators and should be considered in the broader clinical context.

D. Peripheral edema: Swelling in the extremities is not a typical sign of statin-induced muscle injury. It is more commonly associated with cardiac, renal, or hepatic conditions.

A. Statins, such as atorvastatin: Statins primarily lower cholesterol and have no significant interaction with sildenafil that would cause an urgent safety concern. Although monitoring for muscle-related side effects is important with statins, it is not the priority here.

B. Analgesics, such as acetaminophen: Acetaminophen is generally safe and does not interact dangerously with sildenafil. There is no immediate concern related to combining these two medications.

C. Anticoagulants, such as warfarin: There is a potential for increased bleeding risk when sildenafil is combined with anticoagulants, but this is generally not an acute, life-threatening interaction requiring immediate determination before other more critical concerns.

D. Nitrates, such as nitroglycerin: Taking sildenafil with nitrates can cause profound, life-threatening hypotension. Both sildenafil and nitrates can cause vasodilation, and their combined use can lead to a dangerous and potentially fatal drop in blood pressure. This combination is absolutely contraindicated, and the nurse must immediately assess whether the client uses any nitrate medication to prevent a serious adverse event.