What magnesium level is associated with the loss of patellar reflexes?

The loss of patellar reflexes in the context of magnesium levels is typically associated with a state of hypermagnesemia, which is an elevated serum magnesium concentration. Generally, significant clinical manifestations of hypermagnesemia, including the loss of deep tendon reflexes like the patellar reflex, tend to occur when serum magnesium levels reach around 4-5 mEq/L and become more pronounced at higher levels.

Considering the options provided, the level of 8 mEq/L suggests a moderate to high level of magnesium that is likely to impair neuromuscular transmission due to its physiological effects on the neuromuscular junction. At this concentration, the inhibition of neurotransmitter release can lead to decreased excitability of the nervous system, resulting in the loss of reflexes.

In contrast, other levels listed in the choices would typically not yet reach the threshold for causing such a profound neuromuscular effect, thus making the 8 mEq/L level the correct association with the loss of patellar reflexes.