Dantrolene (intravenous)

Dantrolene, also known under US brand names Revonto, Dantrium Intravenous and Ryanodex, is a drug taken via injection to treat malignant hyperthermia, which can occur in some patients during or after anesthesia or surgery.

Overview

Dantrolene is used to treat or prevent a condition known as malignant hyperthermia. This can occur in some patients during or following anesthesia or surgery. Malignant hyperthermia consists of a group of symptoms, including irregular and fast heartbeat, breathing problems and very high fever. It is believed that the tendency to develop this medical condition is inherited. This medication is only available via prescription from your doctor and is available in the dosage forms of powder for solution and powder for suspension.

Condition(s) treated:

  • malignant hyperthermia

Type of medicine

  • powder for solution
  • powder for suspension

Side effects

Along with its intended effects, the consumption of this drug can cause some side effects. Whilst all these side effects may not appear at once, if they do appear, they may require medical attention. Let your doctor or a healthcare professional know immediately if you suffer from any of the following side effects whilst taking dantrolene:

Rare side effects

  • Chest pain
  • Blue fingernails and lips
  • Coughing that sometimes produces a pink frothy sputum
  • Difficulty swallowing
  • Fast, difficult, noisy breathing, sometimes with wheezing
  • Dizziness
  • Hives
  • Fast heartbeat
  • Itching
  • Increased sweating
  • Shortness of breath
  • Pale skin
  • Swelling or puffiness of the eyelids or around the face, eye, tongue or lips
  • Skin rash
  • Tightness in chest
  • Swelling of ankles and legs
  • Tissue necrosis
  • Wheezing
  • Unusual weakness or tiredness

Some side effects of dantrolene that occur do not usually require medical attention. These side effects usually begin to ease once your body starts adjusting to the drug. If these side effects are bothering you, you should contact your local pharmacist or doctor for advice on ways to reduce or prevent these side effects.

Rare side effects

  • Unusually warm skin
  • Redness or flushing of skin

Incidence not known

  • Muscle weakness
  • Drowsiness

Remember, you can report all side effects to the FDA on 1-800-FDA-1088, regardless of severity. Not all side effects are listed, so you may experience others that aren't present on this list. If you experience any behavior that is not normal, contact your doctor right away for advice.

Dosage

The final dosage of any medication will depend on a variety of factors, including your age, weight and height, current medications you are taking, what condition you are being treated for, the severity of your condition and how you react to the first treatment. Do not stop, change or alter a dose without the guidance of your doctor.

Don't be alarmed if your dose does not match those listed below. These doses act as guidelines only and your final dose will be individualized to suit your requirements and condition. Speak with your doctor if you are concerned.

Dantrolene is administered via IV, a needle placed in one of your veins. The typical IV dose for malignant hyperthermia for both adults and children is 2.5 mg/kg, starting around 75 minutes before the patient receives anesthesia. It is infused over approximately a one hour period. This dose should be effective, provided that the usual precautions are followed, such as avoidance of established malignant hyperthermia triggering agents.

If necessary, an additional dose of dantrolene via IV can be given during surgery and anesthesia if blood gas signs of malignant hyperthermia are present, or if a surgery is prolonged. All additional doses are individualized to each patient.

Overdose is possible with any drug. If dantrolene is being used during surgery to treat malignant hyperthermia, trained medical professionals will be able to respond to any signs of an overdose, but if you are taking the drug after surgery and suspect you have overdosed, call 911 or your local poison control center immediately.

Interactions

Interactions between drugs can cause some severe side effects and affect the effectiveness of either drug. To limit these interactions, you should give your doctor or healthcare professional a list of all the current medications you are taking and have taken in the past. This list should include all prescription and non-prescription drugs, vitamins and herbal remedies. You should also include your past medical history, including any medical conditions you are currently suffering from and any health conditions that run in your family history.

The use of the medication is not usually recommended with the following drugs. However, in some cases, it may be required. If you are prescribed both medications together, your doctor may alter the dose or frequency in which you use one or both medications.

  • Alfentanil
  • Alprazolam
  • Amobarbital
  • Amlodipine
  • Anileridine
  • Buprenorphine
  • Aprobarbital
  • Butabarbital
  • Carisoprodol
  • Butalbital
  • Butorphanol
  • Chloral Hydrate
  • Chlorzoxazone
  • Chlordiazepoxide
  • Cinnarizine
  • Clobazam
  • Clevidipine
  • Clonazepam
  • Diazepam
  • Clorazepate
  • Codeine
  • Dantrolene
  • Estazolam
  • Ethchlorvynol
  • Dihydrocodeine
  • Diltiazem
  • Felodipine
  • Flunitrazepam
  • Fentanyl
  • Flurazepam
  • Hydromorphone
  • Halazepam
  • Hydrocodone
  • Isradipine
  • Levorphanol
  • Ketazolam
  • Lorazepam
  • Meperidine
  • Lormetazepam
  • Medazepam
  • Mephenesin
  • Meprobamate
  • Mephobarbital
  • Metaxalone
  • Methocarbamol
  • Methadone
  • Methohexital
  • Midazolam
  • Methotrexate
  • Morphine
  • Nicardipine
  • Morphine Sulfate Liposome
  • Nifedipine
  • Nisoldipine
  • Nimodipine
  • Nitrazepam
  • Oxycodone
  • Oxazepam
  • Oxymorphone
  • Pentobarbital
  • Pentazocine
  • Phenobarbital
  • Primidone
  • Prazepam
  • Propoxyphene
  • Remifentanil
  • Quazepam
  • Secobarbital
  • Sufentanil
  • Sodium Oxybate
  • Tapentadol
  • Thiopental
  • Temazepam
  • Tramadol
  • Verapamil
  • Triazolam

Remember that this list is not complete and some drugs that interact with dantrolene may not be listed here. This is why it's important to let your doctor know of all current and past medications you are taking.

Other interactions

Some medications should not be used at or around the time of eating food or consuming certain types of food, as this can increase the risk of interactions. Using tobacco or alcohol with certain medications may also cause interactions to occur. Speak with your doctor or a healthcare professional about the use of dantrolene with alcohol, food or tobacco.

Warnings

Use in pediatric population

Studies performed to date have not indicated a pediatric-specific problem that could limit the effectiveness of dantrolene in children. Therefore, efficacy and safety have not been established in the use of dantrolene in the younger population.

Use in geriatric population

Appropriate studies on the relationship of age and the effects of dantrolene have not been performed, so no geriatric-specific problems have been demonstrated to date. However, elderly patients are more likely to have age-related heart, kidney or liver issues, which could require a degree of caution in older patients receiving this drug.

Use during pregnancy and breastfeeding

This drug is classified under the FDA's pregnancy category C. It's unknown whether this medication will harm an unborn infant. Tell your doctor if you are pregnant or intend on becoming pregnant whilst using dantrolene.

With regards to breastfeeding, there have currently been no adequate studies done on women for determining the risk to the infant when using this drug during breastfeeding. You should discuss this with your doctor and weigh the potential benefits against the potential risks before deciding to take this medicine whilst breastfeeding.

This medication can cause dizziness, drowsiness or muscle weakness in some individuals. Ensure you know how you react to this medication before you use machinery, drive or do anything else that could be dangerous if you are not alert or dizzy.

Allergies

Let your doctor or a healthcare professional know if you have ever had any unusual allergic reactions to this medication or any other medications. You should also let them know if you suffer from any other types of allergies, such as to animals, foods, preservatives or dyes.

Storage

Typical guidelines state that this medication should be stored in its individual vials at 68°F to 77°F (20°C to 25°C). Do not let this medication freeze. Once thawed, use this medication at once. Do not reuse this medication and contact your local pharmacist for advice on the best method of disposal. Keep away from heat and moisture. Do not keep medicine that is no longer needed or is out of date.

Summary

When used correctly, dantrolene is successful in the treatment of malignant hyperthermia. Your doctor will only give you a couple of doses of this medication until your condition begins to improve, and then you will be switched to an oral medication that works in the same way. Speak with your doctor if you have any concerns about this.

Your doctor will prescribe the exact dose you will receive of this drug and let you know how often it should be given. This medication is given through a needle placed in a vein in your arm.

Due to the extensive list of drugs that can interact with this medication, you should let your doctor know of all drugs you are currently taking before you are prescribed treatment with dantrolene. Let your doctor know if you are currently pregnant or if you are considering pregnancy whilst using dantrolene. When choosing to breastfeed, you should weigh up the pros and cons of taking this medication with your doctor, before you come to a decision.