Reviewed By: Pramod Kerkar, MD, FFARCSI

Why Dantrolene Is Used In Malignant Hyperthermia?

Dantrolene is used in patients with malignant hyperthermia because it helps control the condition and restores normality of vital signs. To be more specific, it inhibits further release of calcium, reduces metabolism and even lowers the high temperature. A patient who has had a negative reactive response to anesthetics needs to be under constant care until the medication has fully taken effect. In case the patient does not respond to the first dosage of Dantrolene after a malignant hyperthermia episode, another round of dosage should be administered after a few minutes. This should be repeated until the patient has stabilized and should be followed up by a prescription of the same drug for about a week.

Malignant hyperthermia is usually managed using Dantrolene, which is a muscle relaxer. The condition, malignant hyperthermia, arises when an individual has a negative reactive response to anesthetics or succinylcholine. Patients who are susceptible to malignant hyperthermia usually exhibit severe symptoms which include high fever, high metabolism rate, muscle stiffness, the breakdown of muscle fibers and calcium homeostasis in skeletal muscles. It is a rare genetic condition which affects about 1:5000 or 1:50,000-10,000 individuals. Because of its rarity and the severity in which the symptoms are experienced by a patient, malignant hyperthermia is considered a life-threatening condition. However, the life expectancy of patients who are malignant hyperthermia susceptible has been improving, thanks to medication such as Dantrolene.

The Development Of Malignant Hyperthermia

A patient will develop malignant hyperthermia, if and only if, they are exposed to anesthetics or succinylcholine muscle relaxer which triggers the condition. The underlying problem is usually an abnormal ryanodine receptor in the skeletal muscle, which controls calcium buildup. Since the receptor is unable to function properly, calcium levels start to rise which results in an increased metabolic rate. Successively, carbon dioxide and acidic levels start to increase, the patient experiences increased heartbeat rate and temperatures, as well as other complications which jeopardize the patient’s life. Due to the fast succession of complications due to the reactive response to anesthetics, the condition needs to be controlled early enough for the treatment used to be successful.

What You Need To Know About Dantrolene And How It Works?

Dantrolene is a type of postsynaptic muscle relaxer often used in the treatment of muscle spasms and stiffness. One of the major symptoms of malignant hyperthermia is muscle rigidity; hence the medication suffices in relaxing the muscles. Doctors offer Dantrolene either intravenously or through an injection or as a drug after a patient has passed the crisis phase and vitals have stabilized.

Once a patient has had a malignant hyperthermia episode, it is crucial that Dantrolene is administered immediately without delay. After that, depending on how the patient responds to the first dose of Dantrolene, another dose can be given thus improving their condition. The process is repeated until the patient is stable and vitals are on a normal range. It is also believed to reduce the release of calcium in the skeletal muscles. As a result, the concurrent responses to the reaction on the anesthetics start to decline until a patient regains normal state in terms of temperature, metabolism, heart rate and acidity levels to name a few. In other words, Dantrolene works by inhibiting release of calcium thus ceasing muscle contraction which has resulted from the onset of the condition. In addition to that, Dantrolene also lowers the high temperature.

Caution To Be Taken With Dantrolene

Dantrolene is alkaline, hence it causes irritation to the skin. It is therefore important that one is cautious enough so that the drug does not infiltrate neighboring tissue which may be affected by the drug. If a patient has an active liver complication, the drug should not be administered so as to avoid any liver damage that can be much fatal. It is important that you follow the doctor’s prescription, after malignant hyperthermia crisis has passed, when at home and do not overdose yourself. Other than that, Dantrolene should not be taken when one needs muscle toning for safe balance and movement during activities. This is because it could lead to muscle weakness, especially in patients with pre-existing muscle conditions. Regardless, the medication does not interfere with the reversal of muscle relaxants.

Pramod Kerkar

Written, Edited or Reviewed By:

, MD,FFARCSI

Pain Assist Inc.

Last Modified On: November 15, 2018

This article does not provide medical advice. See disclaimer

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