<p>The most frequently occurring side effects of Dantrolene have been drowsiness, dizziness, weakness, general malaise, fatigue, and diarrhea. These are generally transient, occurring early in treatment, and can often be obviated by beginning with a low dose and increasing dosage gradually until an optimal regimen is established. Diarrhea may be severe and may necessitate temporary withdrawal of Dantrolene therapy. If diarrhea recurs upon readministration of Dantrolene, therapy should probably be withdrawn permanently</p>