All of the following drugs acts by blocking calcium channels except
Dantrolene is a directly acting skeletal muscle relaxant. It is used for treating malignant hypehermia. It is available as an injection All others are calcium channel blockers used in HTN REF.Essentials of Pharmacology KD Tripathi 8th ed.
Dantrolene
Nicardipine
Diltiazem
Verapamil
Cardiovascular system