Medication Management Flashcards

A nurse notes that a patient's IV infusion of potassium chloride 40 mEq/L is running through a peripheral line at 40 mEq/hr. What is the concern?

Answer: Peripheral infusion of concentrated potassium at this rate causes vein damage and risk of cardiac arrest

IV potassium concentration via peripheral line should not exceed 10 mEq/100 mL (or 10 mEq/hr). High concentrations cause chemical phlebitis and vein sclerosis. Rapid IV potassium can cause fatal cardiac arrhythmias. Central line is preferred for concentrated replacement.

A patient prescribed atorvastatin reports muscle pain and weakness. Which serious complication must be assessed for?

Answer: Rhabdomyolysis — check creatine kinase (CK) level immediately

Statins can cause myopathy ranging from mild myalgia to life-threatening rhabdomyolysis (muscle cell breakdown causing myoglobinuria and renal failure). A markedly elevated CK (>10× upper limit of normal with symptoms) confirms rhabdomyolysis. Stop statin immediately if suspected.

What is the primary mechanism of action of heparin?

Answer: Activates antithrombin III, which inhibits thrombin and factor Xa

Unfractionated heparin binds antithrombin III, dramatically enhancing its ability to inhibit thrombin (factor IIa) and factor Xa, preventing fibrin formation. It does not dissolve existing clots. Warfarin inhibits vitamin K-dependent factors; alteplase is a thrombolytic.

A patient is prescribed an ACE inhibitor (lisinopril). Which adverse effect should be included in patient teaching?

Answer: Persistent dry cough and risk of angioedema

ACE inhibitors cause bradykinin accumulation, leading to a characteristic persistent dry cough in 10–15% of patients. Angioedema (swelling of tongue, lips, throat) is rare but life-threatening. ACE inhibitors also cause hyperkalemia (not hypokalemia) by reducing aldosterone.

A nurse is preparing to administer insulin. The order reads: 'Insulin glargine 20 units subcutaneously at bedtime.' What is the key safety check?

Answer: Verify it is glargine (long-acting) and NEVER mix with any other insulin

Insulin glargine (Lantus) is a long-acting basal insulin with a peakless profile. It must NEVER be mixed with other insulins because mixing alters its pH-dependent precipitation mechanism, changing its pharmacokinetics and making glucose control unpredictable. It is a subcutaneous-only insulin.

A patient taking an MAOI antidepressant needs pain relief. Which medication is absolutely contraindicated?

Answer: Meperidine (pethidine)

The meperidine-MAOI combination causes serotonin syndrome — a potentially fatal interaction characterized by hyperthermia, muscle rigidity, myoclonus, and autonomic instability. Meperidine increases serotonin; MAOIs prevent its breakdown. All opioids (especially fentanyl and tramadol) carry some risk, but meperidine is absolutely contraindicated.