Chemically dantrolene is hydantoin derivative.
Mechanism of Action
It decreases the release of calcium from sarcoplasmic reticulum by binding to special type of calcium receptors, known as Ryanidine receptors. Because of blockage, there is decrease in release of calcium and decrease in spasm.
It has no effects on smooth muscles and cardiac muscles.
Main use is in malignant hyperthermia, an idiosyncratic response seen with general anesthetics.
Besides dantrolene, bromocriptine may be given along with sponging for decreasing temperature.
- Muscle weakness
Given carefully in renal/hepatic diseases. Starting dose is 25 mg, which may be increased to 100 mg.