title: Long term oral Dantrolene Improved Muscular Symptoms in a Malignant Hyperthermia Susceptible Individual.
abstract: This case report describes a female with p.Lys4876Arg amino acid change in the ryanodine receptor type 1 (RYR1) and a sibling who died of malignant hyperthermia (MH) during anesthesia. After her diagnosis as MH susceptible, this patient was administered low-dose dantrolene daily for greater than 25 years for treatment of chronic muscle spasm and pain in her lower extremities and back limiting sleep. Her creatine phosphokinase (CPK) was as high as 2390 IU/L during labor and 900 IU at rest. With 25 mg dantrolene daily, muscle cramps were eliminated, and sleep was improved. Gait instability was noted with dantrolene in the morning, but not when taken at bedtime. There was no evidence of liver injury. This case suggests that low dose dantrolene by mouth could be considered for the treatment of chronic muscle pain in individuals with MH susceptibility.
authors.affiliation: Department of Anesthesiology, Allegheny Health Network, West Penn Hospital, Pittsburgh, PA, USA.
authors.forename: Brian N
authors.initials: BN
authors.lastname: Butala
authors.affiliation: University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA.
authors.forename: Audry
authors.initials: A
authors.lastname: Kang
authors.affiliation: North American Malignant Hyperthermia Registry, UPMC Mercy Hospital, Pittsburgh, PA, USA.
authors.forename: Jasmeen
authors.initials: J
authors.lastname: Guron
authors.affiliation: North American Malignant Hyperthermia Registry, UPMC Mercy Hospital, Pittsburgh, PA, USA.|Department of Anesthesiology, University of Pittsburgh Pittsburgh, PA, USA.
authors.forename: Barbara W
authors.initials: BW
authors.lastname: Brandom
mesh_terms: D000328:Adult; D059350:Chronic Pain / Q000188:drug therapy* / Q000209:etiology; D003402:Creatine Kinase / Q000378:metabolism; D003620:Dantrolene / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008305:Malignant Hyperthermia / Q000150:complications*; D009120:Muscle Cramp / Q000188:drug therapy* / Q000209:etiology; D009125:Muscle Relaxants, Central / Q000008:administration & dosage / Q000494:pharmacology*; D063806:Myalgia / Q000188:drug therapy* / Q000209:etiology; D019837:Ryanodine Receptor Calcium Release Channel
chemical_list: D009125:Muscle Relaxants, Central; D019837:Ryanodine Receptor Calcium Release Channel; D003402:Creatine Kinase; D003620:Dantrolene
keywords: Skeletal muscle ryanodine receptor (RYR1) gene; dantrolene; malignant hyperthermia (MH) susceptibility; myalgia