Which of the following clinical manifestations is likely to occur in a client who received 15 units of rapid-acting insulin before completing a meal?

When a client receives rapid-acting insulin, it is designed to lower blood glucose levels quickly following a meal. If the client has not yet consumed their meal or does not consume enough carbohydrates, the insulin can lead to a significant drop in blood glucose levels, resulting in hypoglycemia.

Weakness is a common manifestation of hypoglycemia. As the body struggles to function without sufficient glucose for energy, individuals may experience symptoms such as fatigue, weakness, and lethargy. This is due to the brain and muscles not receiving the adequate glucose they need to perform optimally, leading to feelings of exhaustion or inability to exert physical energy.

The other symptoms listed, such as drowsiness, polydipsia, and polyuria, are more associated with hyperglycemia or prolonged periods of high blood glucose rather than the immediate effects following an inappropriate insulin dose. Drowsiness may occur later but is not as directly related to the immediate hypoglycemia. Polydipsia (excessive thirst) and polyuria (frequent urination) result from high blood sugar levels, not low, which is what would occur with rapid-acting insulin if food intake is inadequate.