Zeptol CR 400 mg Tablet

Anticonvulsant and mood stabiliser for:

• Epilepsy: focal (partial) seizures and generalised tonic-clonic seizures (not absence or myoclonic)
• Trigeminal neuralgia
• Bipolar disorder (prevention when lithium is unsuitable)
• Diabetic nerve pain, alcohol withdrawal (specialist)

Epilepsy (adults): start 100–200 mg once or twice daily, increase slowly (every 1–2 weeks) to usually 400–1200 mg daily in 2–3 divided doses (CR tablets twice daily); max 1.6–2 g/day.

Children: 5 mg/kg at bedtime, increase to 10–20 mg/kg/day in divided doses (e.g. under 1 year 100–200 mg/day; 1–5 years 200–400 mg; 5–10 years 400–600 mg; 10–15 years 600–1000 mg).

Trigeminal neuralgia: 100 mg one to two times daily, increase to 200 mg three to four times daily (max 1.6 g/day); reduce when pain controlled.

• Do not stop suddenly (seizures). Blood levels may be checked.

• AV heart block, history of bone marrow depression
• Acute intermittent porphyria
• Use with MAO inhibitors (within 14 days), voriconazole, nefazodone
• Allergy to carbamazepine or tricyclic antidepressants

Very common: dizziness, unsteadiness, drowsiness, double vision, nausea, vomiting, raised liver enzymes (GGT).

Common: headache, dry mouth, fluid retention, low sodium, weight gain, rash.

Serious: Stevens–Johnson syndrome/TEN (much higher risk with HLA-B*1502, common in South and Southeast Asian people), DRESS, blood disorders (aplastic anaemia, agranulocytosis, low platelets), hepatitis, heart block, suicidal thoughts.

• Stop and seek urgent care for rash, fever, mouth ulcers, sore throat, bruising or bleeding.
• Consider HLA-B*1502 testing before starting in people of Asian ancestry.
• Blood count, liver function and sodium tests before and during treatment.
• Elderly (confusion, low sodium), heart, liver or kidney disease: caution.
• Avoid driving until stable; reduces effect of hormonal contraceptives.

Risk of birth defects (neural tube defects, others) — specialist planning; take folic acid 5 mg before and during pregnancy; do not stop suddenly. Use reliable non-hormonal or high-dose contraception. Breastfeeding usually acceptable (watch baby for drowsiness, poor feeding).

Carbamazepine lowers levels of many drugs: hormonal contraceptives, warfarin, apixaban/rivaroxaban, ciclosporin, tacrolimus, statins, HIV drugs, antipsychotics, antidepressants, other antiepileptics, corticosteroids, methadone.

Drugs that raise carbamazepine (toxicity): erythromycin, clarithromycin, isoniazid, fluconazole, itraconazole, verapamil, diltiazem, cimetidine, valproate (epoxide), grapefruit juice.

• Phenytoin, phenobarbital, rifampicin lower its levels
• MAO inhibitors (contraindicated); lithium (neurotoxicity)

Drowsiness, unsteadiness, vomiting, seizures, coma, heart rhythm problems, breathing depression. Emergency.

Store below 30°C, protected from moisture (tablets lose effect if damp).