Antiepileptic (sodium channel blocker)
Eslicarbazepine is an antiepileptic medicine used, in combination, to treat partial-onset (focal) seizures in adults and children aged 4 years and older. It reduces the abnormal electrical activity in the brain that causes seizures.
Also known as: Eslicarbazepina, Acetato de eslicarbazepina, Zebinix
Phenytoin + eslicarbazepine: eslicarbazepine inhibits CYP2C19 and increases phenytoin concentrations — QUADRO 2 records the need for phenytoin dose adjustment.
Eslicarbazepine induces CYP3A4 and may reduce phenytoin concentrations; conversely, phenytoin induces eslicarbazepine metabolism, reducing its exposure and efficacy. QUADRO 2 of Annex 7 records this interaction in the eslicarbazepine acetate section. The practical result is a bidirectional interaction with mutual reduction of levels, potentially compromising seizure control of both drugs. The risk is higher in polytherapy patients with difficult epilepsy. Monitor serum levels of both when available and clinical control; adjust doses when introducing or changing either drug.
Eslicarbazepine + phenytoin: mutual induction of metabolism and altered levels — risk of underdosing or toxicity; monitor levels.
Eslicarbazepine inhibits CYP2C19 (which metabolises phenytoin) — increased phenytoin concentrations requiring dose adjustment (QUADRO 2, Eslicarbazepine acetate: "Phenytoin (dose adjustment needed)").
Watch for signs of phenytoin toxicity (nystagmus, ataxia, diplopia).
Phenytoin toxicity after starting eslicarbazepine.
Monitor phenytoin levels when starting eslicarbazepine; adjust the dose as needed.
Prontuário Terapêutico do INFARMED (11th ed., 2012) — Annex 7, QUADRO 2 (Eslicarbazepine acetate)
Levonorgestrel + eslicarbazepine: eslicarbazepine (CYP3A4 and UDP-glucuronyltransferase inducer) reduces the efficacy of hormonal contraceptives (QUADRO 2).
Eslicarbazepine induces CYP3A4 and may accelerate the metabolism of progestogens (such as levonorgestrel) and oestrogens, reducing the efficacy of hormonal contraceptives. QUADRO 2 of Annex 7 records this interaction in the eslicarbazepine acetate section. The risk of contraceptive failure is real in women of childbearing age with epilepsy. Recommend barrier contraception or an alternative non-hormonal method during treatment; for oral contraceptives, consider higher-dose formulations or another method. Reinforce adherence and inform about irregular bleeding as a possible sign of interaction.
Eslicarbazepine + levonorgestrel: enzyme induction — reduced hormonal contraceptive efficacy; use a barrier method.
Eslicarbazepine is a weak CYP3A4 and UDP-glucuronyltransferase inducer — increased metabolism of hormonal contraceptives and reduced efficacy (QUADRO 2, Eslicarbazepine acetate: "Hormonal contraceptives" among the drugs whose metabolism is induced).
Alert the patient to the reduced contraceptive efficacy.
Unplanned pregnancy in a patient on a hormonal contraceptive + eslicarbazepine.
Use an additional (barrier) contraceptive method or a non-hormonal method during eslicarbazepine.
Prontuário Terapêutico do INFARMED (11th ed., 2012) — Annex 7, QUADRO 2 (Eslicarbazepine acetate)
The eslicarbazepine label states: "Eslicarbazepine acetate tablets can be taken with or without food". There is no dietary restriction.
May be taken with or without food, at fixed times.
DailyMed/FDA (NIH/NLM) — approved Eslicarbazepine Acetate tablet label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=28efe9d2-9d7b-4a7c-8458-098456d06604
FDA label (8.1): there is a pregnancy exposure registry (NAAED) that monitors outcomes in women exposed to antiepileptics; the class increases the risk of congenital malformations.
Use with caution in pregnancy; encourage registry enrolment and assess alternatives.
DailyMed/FDA (NIH/NLM) — Eslicarbazepine 8.1: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=22d08671-ac0d-4e3d-8195-929bbb021125
FDA label (8.1): there is a pregnancy exposure registry that monitors outcomes in women exposed to antiepileptics (NAAED Pregnancy Registry). Antiepileptics in general increase the risk of congenital malformations; the risk is not quantified in the eslicarbazepine label.
Potential risk (antiepileptic class); encourage enrolment in the pregnancy registry (NAAED).
No specific breastfeeding data in the label (section 8.2 not detailed in extraction); assess risk/benefit.
Advise contraception and pregnancy planning counselling in women of childbearing potential.
DailyMed/FDA (NIH/NLM) — approved Eslicarbazepine label, section 8.1: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=22d08671-ac0d-4e3d-8195-929bbb021125 ; Prontuário Terapêutico do INFARMED (11th ed., 2012) — Annex 2, Drugs and Breastfeeding: Avoid; no useful information is available.
Clinical and educational support tool. The information does not replace a medical prescription or the opinion of a qualified healthcare professional.
Anticonvulsant: inhibition of voltage-gated sodium channels (presumed mechanism of the active metabolite eslicarbazepine); linear, dose-proportional pharmacokinetics (400-1600 mg/day), steady state in 4-5 days (FDA label 12.1/12.3).
Inhibition of voltage-gated sodium channels; CYP2C19 inhibition and CYP3A4 induction (relevant for interactions).
Rapid oral absorption and well absorbed; most of the administered dose is converted to eslicarbazepine.
Metabolism: extensive conversion to eslicarbazepine (active metabolite); elimination mainly by glucuronidation and renal excretion.
Apparent plasma half-life of eslicarbazepine: 13-20 hours in adult epilepsy patients (FDA label 12.3).
Medicines from the same therapeutic group (ATC classification) or the same pharmacological class.
