Drugs List

Therapeutic Indications

Uses

Muscular spasticity

Contraindications

Children under 5 years
Breastfeeding
Galactosaemia
Hepatic impairment
Pregnancy

Precautions and Warnings

Children aged 5 to 18 years
Females
Patients over 30 years
Cardiovascular disorder
Glucose-galactose malabsorption syndrome
History of hepatic impairment
Lactose intolerance
Respiratory disease

Pre-existing liver dysfunction may enhance risk of hepatotoxicity
Advise ability to drive/operate machinery may be affected by side effects
Only consider re-introduction after liver abnormalities if of major benefit
Contains lactose
Contains sunset yellow (E110) - may cause allergic reaction
Perform liver function tests before commencing therapy and during therapy
During long term use make clinical examinations at regular intervals
Advise patient/carer to contact GP immediately if signs of liver disorder
Discontinue if hepatitis develops
Discontinue at first signs of jaundice
Discontinue if liver function tests become abnormal
Discontinue if no response to treatment after 6 to 8 weeks
Discontinue if severe and persistent diarrhoea develops
Advise patient to avoid alcohol during treatment

Perform liver function tests before commencing therapy to establish baseline liver function and identify any pre-existing liver disease and then continue monitoring these tests during ongoing therapy.
Alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase and total bilirubin should be measured.

Pregnancy and Lactation

Pregnancy

Dantrolene is contraindicated in pregnancy.

Animal studies have proved satisfactory but manufacturer advises avoidance. There is no evidence of first or second trimester exposure to dantrolene sodium and a risk: benefit ratio in humans has not as of yet been established (Briggs, 2011).

The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14 to 17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).

Lactation

Dantrolene is contraindicated in breastfeeding.

Animal studies have proved satisfactory but manufacturer advises avoidance. Dantrolene is secreted in human breast milk and there is no current information available on the long term use of dantrolene during breastfeeding and an alternative drug may be preferred. Relaxant effect of lower doses of the better studied diazepam should be used in short term cases (Schaefer, 2007)

Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
Specialist advice is available from the UK Drugs in Lactation Advisory Service at https://www.midlandsmedicines.nhs.uk/content.asp?section=6&subsection=17&pageIdx=1

Side Effects

Abdominal pain
Abnormal liver function tests
Acne
Anorexia
Blood pressure changes
Chills
Confusion
Constipation
Crystalluria
Depression
Diarrhoea
Dizziness
Drowsiness
Dysphagia
Dyspnoea
Elevation of liver enzymes
Fatigue
Fever
Haematuria
Headache
Hepatitis
Hepatotoxicity
Idiosyncratic hepatic dysfunction
Increased urinary frequency
Insomnia
Intestinal obstruction
Malaise
Nausea
Nervousness
Pericarditis
Pleural effusion
Rash
Respiratory depression
Seizures
Speech disturbances
Sweating
Tachycardia
Urinary incontinence
Urinary retention
Visual disturbances
Vomiting
Weakness

Presentation

Oral formulations of dantrolene.

Drugs List

Therapeutic Indications

Uses

Muscular spasticity

Dosage

Adults

Children

Contraindications

Children under 5 years
Breastfeeding
Galactosaemia
Hepatic impairment
Pregnancy

Precautions and Warnings

Children aged 5 to 18 years
Females
Patients over 30 years
Cardiovascular disorder
Glucose-galactose malabsorption syndrome
History of hepatic impairment
Lactose intolerance
Respiratory disease

Pre-existing liver dysfunction may enhance risk of hepatotoxicity
Advise ability to drive/operate machinery may be affected by side effects
Only consider re-introduction after liver abnormalities if of major benefit
Contains lactose
Contains sunset yellow (E110) - may cause allergic reaction
Perform liver function tests before commencing therapy and during therapy
During long term use make clinical examinations at regular intervals
Advise patient/carer to contact GP immediately if signs of liver disorder
Discontinue if hepatitis develops
Discontinue at first signs of jaundice
Discontinue if liver function tests become abnormal
Discontinue if no response to treatment after 6 to 8 weeks
Discontinue if severe and persistent diarrhoea develops
Advise patient to avoid alcohol during treatment

Perform liver function tests before commencing therapy to establish baseline liver function and identify any pre-existing liver disease and then continue monitoring these tests during ongoing therapy.
Alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase and total bilirubin should be measured.

Pregnancy and Lactation

Pregnancy

Dantrolene is contraindicated in pregnancy.

Animal studies have proved satisfactory but manufacturer advises avoidance. There is no evidence of first or second trimester exposure to dantrolene sodium and a risk: benefit ratio in humans has not as of yet been established (Briggs, 2011).

The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14 to 17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).

Lactation

Dantrolene is contraindicated in breastfeeding.

Animal studies have proved satisfactory but manufacturer advises avoidance. Dantrolene is secreted in human breast milk and there is no current information available on the long term use of dantrolene during breastfeeding and an alternative drug may be preferred. Relaxant effect of lower doses of the better studied diazepam should be used in short term cases (Schaefer, 2007)

Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
Specialist advice is available from the UK Drugs in Lactation Advisory Service at https://www.midlandsmedicines.nhs.uk/content.asp?section=6&subsection=17&pageIdx=1

Side Effects

Abdominal pain
Abnormal liver function tests
Acne
Anorexia
Blood pressure changes
Chills
Confusion
Constipation
Crystalluria
Depression
Diarrhoea
Dizziness
Drowsiness
Dysphagia
Dyspnoea
Elevation of liver enzymes
Fatigue
Fever
Haematuria
Headache
Hepatitis
Hepatotoxicity
Idiosyncratic hepatic dysfunction
Increased urinary frequency
Insomnia
Intestinal obstruction
Malaise
Nausea
Nervousness
Pericarditis
Pleural effusion
Rash
Respiratory depression
Seizures
Speech disturbances
Sweating
Tachycardia
Urinary incontinence
Urinary retention
Visual disturbances
Vomiting
Weakness

Overdosage

It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

The following number will direct the caller to the relevant local centre (0844) 892 0111

Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).

Further Information

Last Full Review Date: May 2015.

Reference Sources

Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 2nd edition (2007) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.

Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 9th edition (2011) ed. Briggs, G., Freeman, R. and Yaffe, S. Lippincott Williams & Wilkins, Philadelphia.

Martindale: The Complete Drug Reference (online) London: Brayfield A (ed). Pharmaceutical Press Accessed on 07 May 2015.

Medications and Mothers' Milk, Sixteenth Edition (2014) Hale, T and Rowe, H, Hale Publishing, Plano, Texas.

Summary of Product Characteristics: Dantrium 25mg capsule. Norgine Ltd. Revised December 2016.
Summary of Product Characteristics: Dantrium 100mg capsule. Norgine Ltd. Revised December 2016.

NICE - Evidence Services
Available at: www.nice.org.uk
Last accessed: 27 June 2017.