Drugs List

Therapeutic Indications

Uses

Hepatic encephalopathy: prevention of recurrence

Treatment for the reduction in recurrence of episodes of overt hepatic encephalopathy in adults.

Contraindications

Children under 18 years
Gastrointestinal obstruction

Precautions and Warnings

Breastfeeding
Pregnancy
Renal impairment
Severe hepatic impairment - Child-Pugh score greater than or equal to 10

Consult national/regional policy on the use of anti-infectives
Consider pseudomembranous colitis if patient presents with diarrhoea
May colour urine red
Advise patient not to take ginkgo unless advised by clinician

In a meta-analysis study, combination therapy with rifaximin and lactulose has shown a statistically significant reduction in mortality in hepatic encephalopathy compared to patients that were treated with lactulose alone.

Pregnancy and Lactation

Pregnancy

Use rifaximin with caution during pregnancy.

At the time of writing, there is limited data on the use of rifaximin in pregnant women.

Animal studies have shown transient effects on ossification and skeletal variations in the foetus. Reproduction studies conducted in pregnant rats with doses of about 2.5 to 5 times the human clinical dose adjusted for body surface area were teratogenetic as were doses in pregnant rabbits of 2 to 33 times the human clinical dose adjusted for body surface area. The effects included cleft palate, agnathia, jaw shortening, small eyes, incomplete ossification and increased thoracolumbar vertebrae.

It is not known if rifaximin crosses the human placenta. The molecular weight (about 786) is low enough for passive transfer. However less than 1% of the oral dose is absorbed into the systemic circulation.

Briggs (2011) suggests the safest course is to avoid rifaximin in the first trimester. Women should be counselled that in the absence of human pregnancy data an accurate assessment of the embryo-foetal risk cannot be made.

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 14-17 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

Use rifaximin with caution during breastfeeding.

It is not known whether rifaximin is excreted in human milk. The low molecular weight (about 786) is low enough for excretion into breast milk, however only small amounts are absorbed into systemic circulation.

The risk to the breastfed child is unknown.

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 distension
Abdominal pain
Abnormal INR
Abnormal liver function tests
Amnesia
Anaemia
Anaphylactic reaction
Angioedema
Anorexia
Anxiety
Arthralgia
Ascites
Asthenia
Attention disturbances
Back pain
Candidiasis
Cellulitis
Confusion
Constipation
Contusion
Convulsions
Dehydration
Depression
Dermatitis
Diarrhoea
Dizziness
Dry mouth
Dyspnoea
Dysuria
Eczema
Falls
Haemorrhage
Headache
Hot flushes
Hyperkalaemia
Hypersensitivity reactions
Hypersomnia
Hypertension
Hypoesthesia
Hypotension
Impaired memory
Insomnia
Loss of balance
Muscle spasm
Myalgia
Nausea
Oedema
Oesophageal varices
Pain
Peripheral oedema
Pleural effusion
Pneumonia
Pollakiuria
Presyncope
Proteinuria
Pruritus
Pyrexia
Rash
Rhinitis
Stomach pain
Syncope
Thrombocytopenia
Upper respiratory tract infection
Urinary tract infections
Vomiting

Presentation

Tablets containing 550 mg rifaximin.

Drugs List

Therapeutic Indications

Uses

Hepatic encephalopathy: prevention of recurrence

Treatment for the reduction in recurrence of episodes of overt hepatic encephalopathy in adults.

Dosage

Adults

Elderly

Contraindications

Children under 18 years
Gastrointestinal obstruction

Precautions and Warnings

Breastfeeding
Pregnancy
Renal impairment
Severe hepatic impairment - Child-Pugh score greater than or equal to 10

Consult national/regional policy on the use of anti-infectives
Consider pseudomembranous colitis if patient presents with diarrhoea
May colour urine red
Advise patient not to take ginkgo unless advised by clinician

In a meta-analysis study, combination therapy with rifaximin and lactulose has shown a statistically significant reduction in mortality in hepatic encephalopathy compared to patients that were treated with lactulose alone.

Pregnancy and Lactation

Pregnancy

Use rifaximin with caution during pregnancy.

At the time of writing, there is limited data on the use of rifaximin in pregnant women.

Animal studies have shown transient effects on ossification and skeletal variations in the foetus. Reproduction studies conducted in pregnant rats with doses of about 2.5 to 5 times the human clinical dose adjusted for body surface area were teratogenetic as were doses in pregnant rabbits of 2 to 33 times the human clinical dose adjusted for body surface area. The effects included cleft palate, agnathia, jaw shortening, small eyes, incomplete ossification and increased thoracolumbar vertebrae.

It is not known if rifaximin crosses the human placenta. The molecular weight (about 786) is low enough for passive transfer. However less than 1% of the oral dose is absorbed into the systemic circulation.

Briggs (2011) suggests the safest course is to avoid rifaximin in the first trimester. Women should be counselled that in the absence of human pregnancy data an accurate assessment of the embryo-foetal risk cannot be made.

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 14-17 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

Use rifaximin with caution during breastfeeding.

It is not known whether rifaximin is excreted in human milk. The low molecular weight (about 786) is low enough for excretion into breast milk, however only small amounts are absorbed into systemic circulation.

The risk to the breastfed child is unknown.

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 distension
Abdominal pain
Abnormal INR
Abnormal liver function tests
Amnesia
Anaemia
Anaphylactic reaction
Angioedema
Anorexia
Anxiety
Arthralgia
Ascites
Asthenia
Attention disturbances
Back pain
Candidiasis
Cellulitis
Confusion
Constipation
Contusion
Convulsions
Dehydration
Depression
Dermatitis
Diarrhoea
Dizziness
Dry mouth
Dyspnoea
Dysuria
Eczema
Falls
Haemorrhage
Headache
Hot flushes
Hyperkalaemia
Hypersensitivity reactions
Hypersomnia
Hypertension
Hypoesthesia
Hypotension
Impaired memory
Insomnia
Loss of balance
Muscle spasm
Myalgia
Nausea
Oedema
Oesophageal varices
Pain
Peripheral oedema
Pleural effusion
Pneumonia
Pollakiuria
Presyncope
Proteinuria
Pruritus
Pyrexia
Rash
Rhinitis
Stomach pain
Syncope
Thrombocytopenia
Upper respiratory tract infection
Urinary tract infections
Vomiting

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: January 2013

Reference Sources

British National Formulary, 64th Edition (2012) Pharmaceutical Press, London.

BNF for Children (2012-2013) Pharmaceutical Press, 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.

Summary of Product Characteristics: Targaxan 550 mg film-coated tablets. Norgine Pharmaceuticals Ltd. Revised March 2021.

US National Library of Medicine. Toxicology Data Network. Drugs and Lactation Database (LactMed).
Available at: https://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT
Rifaximin Last revised: March 1, 2012
Last accessed: January 18, 2013