Anesthesia Technologist Practice Exam

What mechanism does Dantrolene Sodium counteract within muscle cells?

1. Calcium ion release

2. Sodium ion absorption

3. Potassium ion depletion

4. Chloride ion influx

The correct answer is: Calcium ion release

Dantrolene Sodium is primarily used to treat conditions like malignant hyperthermia, which is characterized by a rapid increase in calcium ion concentrations within skeletal muscle cells. The drug functions by interfering with the release of calcium from the sarcoplasmic reticulum, a storage site within muscle cells, and consequently reduces the calcium levels in the cytoplasm. This reduction is essential because excessive calcium in muscle cells leads to sustained muscle contractions, increased metabolism, and, ultimately, the harmful effects associated with malignant hyperthermia. By targeting calcium ion release, Dantrolene effectively counteracts the abnormal physiologic responses seen in conditions where calcium is deregulated, thus helping to restore normal muscle function and prevent the serious consequences of hypermetabolic states in skeletal muscle. Understanding the mechanism of Dantrolene highlights its specific role in muscle physiology and its therapeutic application in critical situations involving elevated intracellular calcium levels.