Dantrolene sodium

{{Infobox drug | name = Dantrolene Sodium | image = Dantrolene_sodium_structure.png | width = 200 | alt = | caption = | pronounce = | tradename = Dantrium, Revonto, Ryanodex | Drugs.com = | MedlinePlus = a682062 | pregnancy_AU = B2 | pregnancy_US = C | legal_AU = S4 | legal_CA = Rx-only | legal_UK = POM | legal_US = Rx-only | routes_of_administration = Oral, Intravenous | bioavailability = 70% | protein_bound = 75% | metabolism = Hepatic | elimination_half-life = 8.7 hours | excretion = Renal | CAS_number = 7261-97-4 | ATC_prefix = M03 | ATC_suffix = CA01 | PubChem = 2952 | DrugBank = DB01219 | ChemSpiderID = 2847 | UNII = F64QU97QCR | KEGG = D00294 | ChEBI = 4316 | ChEMBL = 1433 | IUPAC_name = 1-[[5-(4-nitrophenyl)-2-furanyl]methylene]amino]-2,4-imidazolidinedione }}

Overview

Dantrolene sodium is a muscle relaxant that is primarily used to treat malignant hyperthermia, a rare but life-threatening condition triggered by certain anesthetic agents. It is also used in the management of chronic spasticity associated with conditions such as multiple sclerosis, cerebral palsy, and spinal cord injury.

Mechanism of Action

Dantrolene sodium works by interfering with the release of calcium ions from the sarcoplasmic reticulum of skeletal muscle cells. It binds to the ryanodine receptor (RyR1), inhibiting the release of calcium, which is necessary for muscle contraction. This action reduces muscle tone and helps alleviate spasticity.

Pharmacokinetics

Dantrolene sodium is administered both orally and intravenously. It has a bioavailability of approximately 70% when taken orally. The drug is highly protein-bound (about 75%) and is metabolized in the liver. Its elimination half-life is approximately 8.7 hours, and it is primarily excreted through the kidneys.

Clinical Uses

Malignant Hyperthermia

Dantrolene sodium is the only specific treatment for malignant hyperthermia, a condition characterized by a rapid increase in body temperature and severe muscle contractions. It is administered intravenously in this setting to quickly reduce muscle rigidity and lower body temperature.

Chronic Spasticity

Dantrolene is used to manage chronic spasticity resulting from upper motor neuron disorders such as multiple sclerosis, cerebral palsy, and spinal cord injury. It helps improve mobility and reduce discomfort associated with muscle stiffness.

Adverse Effects

Common side effects of dantrolene sodium include muscle weakness, drowsiness, dizziness, and fatigue. More serious adverse effects can include liver toxicity, which necessitates regular monitoring of liver function tests during treatment.

Contraindications

Dantrolene sodium is contraindicated in patients with active liver disease and should be used with caution in patients with impaired pulmonary function or cardiac disease.

Drug Interactions

Dantrolene may interact with other central nervous system depressants, leading to increased sedation. It can also potentiate the effects of non-depolarizing muscle relaxants and should be used cautiously in combination with these agents.

Conclusion

Dantrolene sodium is a critical medication in the management of malignant hyperthermia and chronic spasticity. Its unique mechanism of action and specific indications make it an essential drug in certain clinical scenarios.

See Also

• Malignant hyperthermia
• Muscle relaxant
• Calcium channel

External Links

• Drugs.com: Dantrolene
• MedlinePlus: Dantrolene

Muscle relaxants

• Baclofen
• Carisoprodol
• Chlorzoxazone
• Cyclobenzaprine
• Dantrolene
• Metaxalone
• Methocarbamol
• Orphenadrine
• Tizanidine