The most common side effect of oral dantrolene used to prevent malignant hyperthermia is which?

The most common side effect of oral dantrolene used to prevent malignant hyperthermia is which?

• A. Nausea and vomiting
• B. Muscle weakness
• C. Blurred vision
• D. Hepatitis

Answer: (B)

The main idea is that dantrolene’s effect on skeletal muscle underlies its most common side effect. Dantrolene directly inhibits calcium release from the sarcoplasmic reticulum in skeletal muscle, which reduces excitation-contraction coupling and weakens muscle contraction. Because this action affects muscles broadly, the most frequent adverse effect is generalized muscle weakness, often most noticeable in proximal muscles. Nausea, vomiting, or blurred vision can occur, but are less common, and hepatitis is a more serious risk typically associated with longer-term use rather than the usual prophylactic course. So, the muscle weakness reflects the drug’s mechanism and is the most typical side effect.

The main idea is that dantrolene’s effect on skeletal muscle underlies its most common side effect. Dantrolene directly inhibits calcium release from the sarcoplasmic reticulum in skeletal muscle, which reduces excitation-contraction coupling and weakens muscle contraction. Because this action affects muscles broadly, the most frequent adverse effect is generalized muscle weakness, often most noticeable in proximal muscles. Nausea, vomiting, or blurred vision can occur, but are less common, and hepatitis is a more serious risk typically associated with longer-term use rather than the usual prophylactic course. So, the muscle weakness reflects the drug’s mechanism and is the most typical side effect.