Carbamazepine
In brief
- Carbamazepine is a prescription-only medicine (POM) in the UK; it is supplied only with a valid prescription and is not available OTC.
- Carbamazepine is used to treat epilepsy (partial and generalised tonic‑clonic seizures), trigeminal neuralgia and as a mood stabiliser in bipolar disorder; it is a carboxamide antiepileptic that stabilises hyperexcited neuronal membranes primarily by blocking voltage‑gated sodium channels and reducing repetitive neuronal firing.
- Usual doses vary by indication: adults commonly start 100–200 mg twice daily with maintenance typically 800–1,200 mg/day (up to 1,600 mg/day in some cases); trigeminal neuralgia often begins 100 mg twice daily up to 1,200 mg/day; children are dosed by weight (typically 5–20 mg/kg/day divided doses) and elderly require lower starting doses and slower titration.
- Administration is oral (tablets, prolonged/controlled‑release tablets, chewable tablets, oral suspension).
- Onset of action for immediate‑release oral carbamazepine is usually within 1–4 hours; clinical effects for seizure control or neuropathic pain may take days of titration to become apparent.
- Duration of action depends on formulation: immediate‑release preparations typically act for about 8–12 hours requiring divided dosing, while controlled‑release formulations provide prolonged effects often covering 12–24 hours; note carbamazepine induces its own metabolism over time, altering plasma levels.
- Avoid alcohol while taking carbamazepine; alcohol increases central nervous system depression (drowsiness, dizziness) and can worsen side effects and seizure control.
- The most common side effects are dizziness and drowsiness (also nausea, vomiting, mild skin rash, blurred vision, ataxia and hyponatraemia are frequently reported).
- Would you like to try carbamazepine without a prescription?
Basic carbamazepine information
- INN (international nonproprietary name): Carbamazepine
- Brand names available in the United Kingdom: Tegretol (including Tegretol Retard prolonged-release tablets) and generic carbamazepine
- ATC code: N03AF01
- Forms and dosages: tablets 100 mg, 200 mg, 400 mg; chewable tablets; prolonged-release tablets 200 mg, 400 mg; oral liquid 100 mg/5 mL
- Manufacturers in the United Kingdom: Novartis (Tegretol) and several generic manufacturers
- Registration status in the United Kingdom: Prescription‑only medicine licensed and regulated by MHRA
- OTC / Rx classification: Prescription-only medicine (POM)
Legal status and availability in the UK
Carbamazepine is a prescription-only medicine (POM) in the UK, supplied on NHS or private prescriptions.
In our online pharmacy, carbamazepine is available without a prescription, with discreet delivery to the United Kingdom in 9–21 days.
INN, synonyms and classification
The International Nonproprietary Name (INN) is carbamazepine.
Carbamazepine is classified in the ATC system as N03AF01 — a carboxamide derivative within antiepileptics.
This classification places it among first‑line anticonvulsant choices for certain seizure types.
Brands
Tegretol (Novartis) is the most widely recognised brand in the UK, alongside Tegretol Retard prolonged‑release tablets and generic carbamazepine.
Licensed indications
Carbamazepine is licensed for focal (partial) seizures and for generalised tonic–clonic seizures.
It is also a first‑line option for trigeminal neuralgia where it delivers reliable pain control in most patients.
Use as a mood stabiliser in bipolar disorder is for patients who do not respond to lithium and should be managed by specialists.
Off‑label and specialist use
Off‑label uses include certain neuropathic pain syndromes.
UK prescribers balance the benefits with risks such as CYP interactions and teratogenicity when considering off‑label use.
Maintenance for epilepsy is commonly long‑term with periodic review, whereas neuralgia courses may be for several months and tapered where symptoms remit.
| Indication | Typical maintenance dose band |
|---|---|
| Epilepsy (Adults) | 800–1,200mg/day |
| Trigeminal neuralgia | Up to 1,200mg/day (titrated) |
| Bipolar disorder (lithium‑unresponsive) | Variable — specialist guidance |
Available forms and common strengths
Carbamazepine is available as immediate‑release tablets (100mg, 200mg, 400mg) and as prolonged/controlled‑release tablets (200mg, 400mg).
Oral liquid at 100mg/5ml and chewable tablets are also available.
| Dosage form | Strengths | Typical pack sizes |
|---|---|---|
| Tablets | 100mg, 200mg, 400mg | 28, 56, 100 (blisters) |
| Controlled‑release tablets | 200mg, 400mg | 28, 56 (blisters) |
| Oral liquid | 100mg/5ml | 100ml bottle (with dosing syringe) |
Adult dosing and titration
Typical adult initiation is 100–200mg twice daily with gradual titration to response.
Maintenance dosing for epilepsy commonly falls between 800–1,200mg per day depending on response and tolerability.
For trigeminal neuralgia, clinicians often start at 100mg twice daily and titrate to effect.
CR formulations usually permit twice‑daily dosing while immediate‑release forms may require three times daily administration.
- Example titration: 100mg twice daily for 3–7 days → increase by 100–200mg total per week to target.
Children, elderly and hepatic/renal adjustments
Children often start at around 10–20mg/kg/day divided, with stepwise titration guided by age and weight.
The elderly need lower starting doses and slower titration due to CNS sensitivity and a higher risk of hyponatraemia.
Liver impairment should prompt avoidance where possible or use of the minimum effective dose with close monitoring.
Renal impairment requires caution and monitoring of carbamazepine and its metabolites rather than a fixed dosing rule.
Absolute contraindications
Do not use carbamazepine in patients with prior hypersensitivity to carbamazepine or tricyclic compounds.
Atrioventricular block and a history of bone marrow depression are absolute contraindications.
Concurrent or recent use of monoamine oxidase inhibitors (within 14 days) is also contraindicated.
HLA‑B*1502 carriage is an important genetic risk factor in certain ethnic groups and should be considered when relevant.
Warnings, pregnancy and regulatory points
Pregnancy carries teratogenic risk and continuation should be assessed by specialists with documented counselling.
Folic acid supplementation is recommended when carbamazepine is continued in women of childbearing potential.
MHRA guidance requires careful risk–benefit consideration and appropriate documentation when prescribing to women who could become pregnant.
Remember that carbamazepine remains Rx‑only under UK regulation and prescriptions must meet standard labelling and dispensing standards.
Common and predictable adverse effects
Mild to moderate adverse effects include dizziness, drowsiness, nausea and vomiting.
Patients commonly report headache, blurred vision and ataxia during early titration phases.
Mild skin rashes may occur and can precede severe cutaneous reactions; any evolving rash warrants prompt review.
Hyponatraemia (SIADH) and transient leucopenia are recognised and should be on the monitoring checklist.
Serious risks and monitoring schedule
Serious but rare events include agranulocytosis, aplastic anaemia and Stevens‑Johnson syndrome / toxic epidermal necrolysis.
Recommended baseline tests: full blood count, liver function tests and serum sodium prior to or shortly after initiation.
Periodic monitoring of FBC, LFTs and sodium is advised during maintenance; therapeutic drug monitoring supports dose changes.
| Adverse effect frequency | Monitoring action |
|---|---|
| Common (dizziness, drowsiness) | Clinical review; dose adjustment if persistent |
| Hyponatraemia | Serum sodium baseline and periodic checks |
| Blood dyscrasia (rare) | Baseline and periodic full blood counts; urgent review for fever or sore throat |
Red flags: fever, sore throat, unexplained bruising, mouth ulcers, widespread rash, severe drowsiness or breathlessness — seek urgent review.
Mechanism and interaction risk
Carbamazepine is a potent inducer of hepatic enzymes including CYP3A4 and affects multiple drug pathways.
Induction reduces concentrations of many co‑medicines such as some oral contraceptives, anticoagulants and statins, altering clinical effects.
Enzyme induction also affects other antiepileptics and certain antipsychotics, so interaction checking is essential at prescribing and dispensing.
Practical management of interactions
Flag interacting medicines at point of sale and during pharmacy consultations to ensure safe use.
Women on hormonal contraception should be counselled about reduced efficacy and offered alternative or additional contraception.
Coordinate dose changes with prescribers and consider therapeutic drug monitoring when starting or stopping interacting drugs.
| Drug class | Effect | Practical advice |
|---|---|---|
| Hormonal contraceptives | Reduced efficacy | Advise additional/alternative contraception |
| Anticoagulants | Variable effect on levels | Coordinate INR monitoring and prescriber liaison |
| Other antiepileptics | Altered plasma concentrations | Use TDM and clinical monitoring |
Indications to measure levels
Measure plasma carbamazepine when initiating or titrating, if seizures persist, when toxicity is suspected or when interacting drugs are added or removed.
Testing is also indicated during pregnancy and in significant hepatic or renal impairment, or when adherence is uncertain.
Interpretation and target ranges
Typical therapeutic ranges are approximately 4–12 mg/L, but local laboratory reference ranges should be used for interpretation.
Trough (pre‑dose) samples give the most consistent interpretation and can be repeated after dose changes.
| When to test | Sample timing | Action |
|---|---|---|
| Initiation/titration | Trough sample | Adjust dose per level and clinical response |
| Suspected toxicity | As soon as possible | Assess levels, treat symptoms, consider holding dose |
| Drug interaction change | Trough after steady state | Recheck and liaise with prescriber |
Clinicians interpret levels alongside symptoms.
Pregnancy, breastfeeding and contraception
Pregnancy requires specialist assessment because of teratogenic risk; decisions balance seizure control against foetal risk.
Folic acid supplementation is advised where carbamazepine is continued in women of childbearing potential.
Breastfeeding may be permitted with monitoring and specialist input; counsel mothers in line with clinical advice.
Overdose, perioperative and emergency measures
Overdose is a medical emergency and can cause CNS depression, cardiac arrhythmias and respiratory compromise.
Perioperative teams should be informed as enzyme induction can alter anaesthetic and adjunct drug levels.
Emergency symptoms: severe drowsiness, irregular heartbeat, breathing difficulty — call emergency services immediately.
Efficacy and tolerability comparison
Carbamazepine is a proven option for focal seizures and remains a first‑line choice in classic trigeminal neuralgia.
Oxcarbazepine is often considered as an alternative with a different hyponatraemia profile, though cross‑reactivity for allergic reactions may occur.
Lamotrigine has a favourable cognitive and mood profile and is preferred in some bipolar presentations and where interaction burden must be minimised.
When carbamazepine is preferred
Carbamazepine is preferred when there is established efficacy for a patient’s seizure type or clear benefit in trigeminal neuralgia.
Choose alternatives where teratogenicity, interaction burden or blood dyscrasia risks outweigh expected benefits.
| Drug | Pros | Cons |
|---|---|---|
| Carbamazepine | Proven efficacy for focal seizures, trigeminal neuralgia | Enzyme induction, teratogenic risk, blood monitoring |
| Oxcarbazepine | Fewer enzyme interactions (some benefits) | Hyponatraemia still possible; cross‑reactivity risk |
| Lamotrigine | Favourable cognitive profile, useful in bipolar | Risk of rash; slower titration |
Recommended storage and handling
Store carbamazepine between 15–30°C, protected from moisture and direct light.
Do not freeze oral suspensions and keep medicines in their original packaging with the leaflet.
During transport avoid excessive heat; controlled ambient conditions are advised for pharmacy logistics.
Dispensing advice and shelf life
Record batch and expiry on dispensing records and ensure clear labelling for the patient.
Advise patients that suspensions may have an expiry after opening and supply a dosing syringe with liquids.
For controlled‑release tablets remind patients not to crush or chew them.
- Dispensing checklist: confirm allergies, pregnancy status, concomitant medicines, supply PIL and monitoring plan.
Counselling essentials
Explain missed‑dose advice: take the missed dose as soon as remembered unless it is near the next dose; never double up doses.
Counsel about driving and operating machinery until the patient is stable on dose because of drowsiness and dizziness risks.
Warn patients that alcohol can worsen CNS side effects and should be avoided while stabilising.
Discuss contraception and reduced efficacy of hormonal methods due to enzyme induction and offer practical alternatives.
Quick FAQs
- Can I stop suddenly? No — treatment must be tapered under clinician guidance to avoid seizure worsening.
- What side effects need urgent review? Fever, rash, mouth ulcers, severe drowsiness or breathlessness require immediate assessment.
- Is monitoring needed? Yes — baseline and periodic blood tests including FBC, LFTs and serum sodium are recommended.
Delivery across the United Kingdom
| City | Region | Delivery Time |
|---|---|---|
| London | England | 9–21 days |
| Birmingham | England | 9–21 days |
| Manchester | England | 9–21 days |
| Glasgow | Scotland | 9–21 days |
| Edinburgh | Scotland | 9–21 days |
| Leeds | England | 9–21 days |
| Liverpool | England | 9–21 days |
| Bristol | England | 9–21 days |
| Newcastle Upon Tyne | England | 9–21 days |
| Sheffield | England | 9–21 days |
| Cardiff | Wales | 9–21 days |
| Belfast | Northern Ireland | 9–21 days |
