A nurse is assessing a client who has taken omeprazole for over 10 years and recently reported experiencing severe muscle cramps. Which of the following electrolyte imbalances should the nurse consider as possibly contributing to this issue?

A. Hypercalcemia: Elevated calcium levels are not commonly associated with long-term omeprazole use. Hypercalcemia typically presents with fatigue, constipation, and kidney stones rather than muscle cramps. B. Hypomagnesemia: Long-term use of proton pump inhibitors like omeprazole can lead to decreased magnesium absorption, resulting in hypomagnesemia. Low magnesium levels can cause neuromuscular excitability, leading to severe muscle cramps, tremors, and even arrhythmias. C. Hyponatremia: Sodium imbalances are not a known effect of omeprazole therapy. Hyponatremia usually presents with confusion, lethargy, and seizures rather than isolated muscle cramps. D. Hyperkalemia: Elevated potassium levels are not typically caused by omeprazole. Hyperkalemia primarily affects cardiac function and may present with arrhythmias, not muscle cramps.