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Carbamazepine rectal


Suppositories containing carbamazepine

Drugs List

  • carbamazepine 125mg suppository
  • carbamazepine 250mg suppository
  • Therapeutic Indications


    Epilepsy - partial seizures
    Epilepsy - tonic-clonic seizures


    Dose adjustment should always depend on the clinical response in the individual patient. Monitoring of plasma levels may be useful in certain conditions.

    The suppositories are intended for short term use (7 days of less) in patients where the oral route is temporarily not available, for example post-operatively or in unconscious subjects.


    The maximum daily dose is 250 mg at 6 hour intervals (or 1000 mg daily) using suppositories.

    If switching from oral formulations a dosage increase of approximately 25% is required
    125 mg is equivalent to 100 mg of carbamazepine in tablet or liquid form
    250 mg is equivalent to 200 mg of carbamazepine in tablet or liquid form


    The maximum daily dose is 250 mg at 6 hour intervals (or 1000 mg daily) using suppositories.

    If switching from oral formulations a dosage increase of approximately 25% is required
    125 mg is equivalent to 100 mg of carbamazepine in tablet or liquid form
    250 mg is equivalent to 200 mg of carbamazepine in tablet or liquid form


    Children aged 1 month to 18 years
    The maximum daily dose is 250 mg at 6 hour intervals (or 1000 mg daily) using suppositories.

    If switching from oral formulations a dosage increase of approximately 25% is required
    125 mg is equivalent to 100 mg of carbamazepine in tablet or liquid form
    250 mg is equivalent to 200 mg of carbamazepine in tablet or liquid form

    Additional Dosage Information

    If sudden withdrawal is required due to adverse reactions, the change to alternative medication should be under the cover of a suitable alternative such as intravenous or rectal diazepam or intravenous phenytoin.

    Therapeutic Drug Monitoring

    Refer to local therapeutic drug monitoring service for specific local carbamazepine guidelines.

    Monitoring of plasma levels may be useful in certain conditions: dramatic increase in seizure frequency, verification of patient compliance, during pregnancy, when treating children or adolescents, possible absorption disorders and in suspected toxicity when more than one drug is being used.

    Steady state plasma concentrations vary inter-individually, but are usually achieved within a period of 1 to 2 weeks. The recommended therapeutic plasma concentration range is between 4 to 12 microgram per ml (17 to 50 micromoles per litre).

    Using AUC calculations the total bioavailability of carbamazepine suppositories is approximately 25% less than oral formulations.
    For doses up to 300 mg approximately 75% of the total amount absorbed reaches the general circulation within 6 hours of application.
    Consequently the maximum dosage per day is 1000 mg (equivalent of 800 mg oral formulation).
    Clinical trials have shown plasma levels using suppositories are within the range 5 to 8 micrograms/ml (19 to 34 micromol/litre).

    To avoid reduced effect or risk of breakthrough seizures or excessive side effects, it may be prudent to avoid changing the formulation. Bioavailability is unaffected by food regardless of formulation. Increased frequency of seizures may occur during switchover from oral formulation to suppositories.

    Owing to enhanced carbamazepine elimination, children may require higher doses of carbamazepine (in mg/kg) than adults to maintain therapeutic concentrations.

    Carbamazepine is 70 to 80% bound to serum protein.

    Carbamazepine induces its own metabolism and the half life falls with repeated dosing. The elimination half-life of unchanged drug in the plasma averages 36 hours following a single dose. After repeated dosing (which leads to auto-induction of the hepatic enzymes) the half-life falls to approximately 16 to 24 hours. In patients receiving concomitant enzyme-inducing medications (phenobarbitone, phenytoin) the half life may be further reduced to 9 to 10 hours.


    Neonates under 1 month
    Within 2 weeks of discontinuing MAOIs
    Atrioventricular block
    History of myelosuppression

    Precautions and Warnings

    East Asian ancestry
    Cardiac impairment
    Haematological disorder
    Hepatic impairment
    History of drug induced haematological reactions
    Renal impairment
    Urinary retention

    Advise impaired alertness may affect ability to drive or operate machinery
    Confirm HLA-B 1502 status in Han Chinese & Thai patients before initiating
    Cross sensitivity can occur with other antiepileptics
    Folic acid 5mg daily required pre-conception to end of 1st trimester
    Increased risk of osteomalacia; consider vitamin D supplement
    Prescribe by manufacturer's product to ensure seizure control maintenance
    Increase in seizures may occur during switch from oral to suppositories
    Short term (7 day) replacement for oral forms when oral route not available
    Blood counts should be performed before and periodically during treatment
    Monitor hepatic function before treatment and regularly during treatment
    Perform urine analysis before and periodically during treatment
    Breastfeeding: Monitor infant for systemic effects of treating the mother
    Monitor patients at risk of glaucoma for increases in intraocular pressure
    Monitor plasma sodium in patients at risk of hyponatraemia
    Monitor renal function
    Monitor serum biochemistry regularly
    Monitor thyroid function regularly
    Plasma level monitoring may be useful: refer to local guidelines
    Refer women considering pregnancy for specialist advice and monitoring
    Advise patient to seek medical advice if severe skin reaction occurs
    Advise patients to report signs of hepatic damage (malaise, jaundice etc.)
    Advise patients/carers to seek medical advice if suicidal intent develops
    Consult once if rash, sore throat, mouth ulcers, bruising,fever occur
    May cause activation of latent psychosis
    May cause agitation and confusion in the elderly
    Avoid abrupt withdrawal
    Discontinue if epilepsy is exacerbated
    Discontinue if evidence of significant bone marrow depression
    Discontinue if hypersensitivity reactions occur
    Discontinue if severe skin reaction occurs
    Discontinue if significant leucopenia occurs
    Discontinue if significant/persistent hepatic function abnormalities occur
    Bioavailability differs with preparations;caution on changing formulations
    Advise patient not to take St John's wort concurrently
    Advise patient to avoid alcohol during treatment
    Advise patient grapefruit products may increase plasma level
    May affect spermatogenesis
    Female: Non-hormonal contraception or minimum 50mcg oestrogen advised
    Neonate exposed in utero: Administer vitamin K at birth
    Pregnancy: Administer vitamin K in the last few weeks of pregnancy

    Severe dermatological reactions
    Severe dermatological reactions such as toxic epidermal necrolysis and Stevens-Johnson syndrome have been rarely reported during treatment with carbamazepine. These reactions usually appear within the first few months of treatment. The HLA-B*1502 allele has been strongly associated with risk of developing Stevens-Johnson syndrome. Genetic screening of patients who are of Han Chinese or Thai origin should be considered as the HLA-B*1502 allele is more prevalent in these populations (approximately 10%). If patient tests positive for this allele carbamazepine treatment should not be initiated unless there is no other therapeutic option.

    Severe dermatological reactions have also been associated with the HLA-A*3101 allele in European and Japanese populations. There is currently there is insufficient data to support genetic testing for this allele, although if a patient is known to be positive for the allele, the use of carbamazepine may be considered if the benefits are thought to outweigh the risk.

    Milder reactions (macular and maculopapular exanthema) may also occur and may dissipate upon dose reduction or continued treatment; these patients should be monitored closely for potential immediate withdrawal on worsening reaction.

    Antiepileptic drug hypersensitivity
    Patients usually present with fever, rash, lymphadenopathy and other organ system involvement. Other possible symptoms include liver dysfunction, haematological, renal and pulmonary abnormalities, vasculitis and multi-organ failure. If signs or symptoms of hypersensitivity syndrome occur, the drug should be withdrawn immediately and expert advice sought.

    Suicidal ideation
    Antiepileptic treatment is associated with a small increased risk of suicidal thoughts and behaviour, available data suggest that the increased risk applies to all antiepileptics and is seen as early as one week after starting treatment. Patients (and carers of patients) should be alert to any mood changes, distressing thoughts, or feelings about suicide or harming themselves at any point during treatment. They should be advised to seek medical advice if they develop such thoughts or behaviour, and should be referred for appropriate treatment if necessary.
    The available evidence does not define whether the risk of suicidal thoughts and behaviour differs between antiepileptics. Patients should not stop or switch treatment on the basis of this information and without speaking to a healthcare professional.

    Pregnancy and Lactation


    Use carbamazepine with caution in pregnancy.

    Use minimum effective doses cautiously in pregnancy, with monitoring of plasma concentrations.

    Women of child bearing potential wherever possible should be prescribed monotherapy. The incidence of congenital abnormalities is less in the offspring of monotherapy patients. There is an increased risk of teratogenicity during pregnancy, particularly if the woman is being treated with a combination of antiepileptic drugs.

    Folic acid deficiency is known to occur during pregnancy. Antiepileptic medication is known to aggravate this deficiency. It is recommend that folic acid 5 mg daily should be prescribed to all women with epilepsy who are taking antiepileptic drugs, prior to conception and continued until the 12th week of pregnancy.

    Use of carbamazepine in pregnancy is associated with an increase in both minor and major malformations. There are reports of developmental disorders and malformations, including spina bifida, and also other congenital anomalies e.g. craniofacial defects, cardiovascular malformations, hypospadias and anomalies involving various body systems. However, developmental disorders including malformations have occurred in the offspring of mothers with untreated epilepsy. Patients should be counselled regarding the possibility of increased risk of malformations and given the opportunity of antenatal screening.

    Adjusting or stopping any anti-epileptic medication during pregnancy should not be done without specialist advice, and the relative benefits and risks should be discussed carefully first. The risk of inadequate seizure control may be more detrimental to the foetus than the use of antiepileptic drugs. Pregnancy in epileptic women is associated with a higher risk of congenital abnormalities, which are mainly associated with the use of anti-epileptic drugs rather than the disease itself. This risk is increased when multiple drugs are used. Routine monitoring of antiepileptic drugs is not recommended, but may be useful in cases where seizures have increased or are likely to, in order to plan the extent of dose adjustment needed.

    Maternal use of carbamazepine with a concurrent second antiepileptic has in some cases resulted in neonatal seizures and/or respiratory depression. Neonatal vomiting, diarrhoea and/or decreased feeding have also been reported. These reactions may represent a neonatal withdrawal syndrome. Vitamin K1 should be given to the mother during the later stages of pregnancy as well as to the newborn to prevent bleeding disorders in the infant.

    Animal studies in mice, rats and rabbits found an increased embryo mortality when administered during organogenesis at maternally toxic doses (20 times the usual human dosage). Rat foetuses also showed growth retardation at maternally toxic doses.

    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 ( ) or if this is unavailable at the backup site ( ).


    Use carbamazepine with caution in breastfeeding.

    Carbamazepine passes into breast milk (about 25 to 60% of the plasma concentrations).

    The benefits of breast feeding should be weighed against the remote possibility of adverse events happening in the infant.
    Mothers treated with carbamazepine may breast feed their infants provided the infant is monitored for adverse reactions such as vomiting, sedation, poor sucking, withdrawal reactions and hepatic dysfunction. If these occur, the concentration of carbamazepine in the infant's serum should be measured, and liver values also measured in suspicious cases.

    Monitor the infant for jaundice, drowsiness, adequate weight gain, and developmental milestones, especially in younger, exclusively breastfed infants and when using combinations of anticonvulsant or psychotropic drugs.

    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


    Advise patients to seek immediate medical advice if reactions such as fever, sore throat, rash, ulcers in the mouth, easy bruising, petechial or purpuric haemorrhage occur. Advise patients that their ability to drive and operate machinery may be impaired by treatment. Women of child-bearing age should be informed of the potential risks and benefits of continuing anti-epileptic treatment throughout pregnancy. Patients should be advised to consult their physician if they are planning a pregnancy, and consider taking folic acid 5mg daily before conception. Patients should be counselled regarding the possibility of increased risk of malformations and given the opportunity of antenatal screening. Advise patients to refrain from alcohol consumption as tolerance of alcohol is reduced.Advise patient to avoid grapefruit products. Advise patient not to use products containing St John's wort with carbamazepine. Patients and caregivers should be aware of the need to monitor for the emergence of suicidal thoughts and behaviour, and the need to seek medical advice immediately if they present.

    Side Effects

    Acute intermittent porphyria
    Aggravation of coronary artery disease
    Allergic skin reactions
    Anaphylactic reaction
    Aplastic anaemia
    Aseptic meningitis
    Atrioventricular block
    Changes of blood pressure
    CNS disturbances
    Congestive cardiac failure
    Decrease in plasma calcium
    Decreased appetite
    Delayed hypersensitivity reactions
    Elevation of liver enzymes
    Erythema multiforme
    Erythema nodosum
    Exfoliative dermatitis
    Fluid retention
    Folic acid deficiency
    Gastro-intestinal symptoms
    Haemolytic anaemia
    Hair loss
    Hearing disturbances
    Hepatic failure
    Hypersensitivity reactions
    Impaired renal function
    Increase in plasma cholesterol
    Increased intra-ocular pressure
    Increased prolactin
    Interference with spermatogenesis
    Interstitial nephritis
    Involuntary movement disorders
    Lymphoma-like disorder
    Megaloblastic anaemia
    Muscle weakness
    Muscular cramps
    Neuroleptic malignant syndrome
    Paretic symptoms
    Peripheral neuropathy
    Possible alteration of thyroid function tests
    Rectal irritation
    Red cell aplasia
    Renal failure
    Sexual disturbances
    Skin pigmentation changes
    Speech disturbances
    Stevens-Johnson syndrome
    Systemic lupus erythematosus
    Taste disturbances
    Toxic epidermal necrolysis
    Urinary frequency
    Urinary retention
    Vanishing bile duct syndrome
    Visual disturbances
    Weight gain


    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 ( ) or if this is unavailable at the backup site ( ).

    Further Information

    Last Full Review Date: March 2014

    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. Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press [Accessed on [March 12, 2014]].

    Martindale: The Complete Drug Reference, 37th edition (2011) ed. Sweetman, S. Pharmaceutical Press, London.

    Paediatric Formulary Committee. BNF for Children 2013-2014. London: BMJ Group, Pharmaceutical Press, and RCPCH Publications; 2013. Paediatric Formulary Committee. BNF for Children (online) London: BMJ Group, Pharmaceutical Press, and RCPCH Publications [Accessed on [March 12, 2014].

    Summary of Product Characteristics: Tegretol Suppositories. Novartis Pharmaceuticals UK Ltd. Revised January 2014.

    US National Library of Medicine. Toxicology Data Network. Drugs and Lactation Database (LactMed).
    Available at:
    Last accessed: March 12, 2014

    Clinical Knowledge Summaries - Pre-conception - advice and management - Management
    Available at:
    Last accessed: March 12, 2014

    Clinical Knowledge Summaries - Epilepsy - Management
    Available at:
    Last accessed: March 12, 2014

    NICE clinical guideline 137 - The epilepsies, January 2012
    Available at:
    Last accessed: March 12, 2014

    MHRA Drug Safety Update Vol 2, Issue 1, August 2008
    Antiepileptics: risk of suicidal thoughts and behaviour
    Available at:
    Last accessed: March 12, 2014

    MHRA Drug Safety Update Vol 2, Issue 9, April 2009
    Antiepileptics: adverse effects on bone
    Available at:
    Last accessed: March 12, 2014

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