Chemical formula: C₁₀H₈F₂N₄O Molecular mass: 238.194 g/mol PubChem compound: 129228
Rufinamide interacts in the following cases:
Rufinamide has been shown to induce the cytochrome P450 enzyme CYP3A4 and may therefore reduce the plasma concentrations of substances which are metabolised by this enzyme. The effect was modest to moderate. The mean CYP3A4 activity, assessed as clearance of triazolam, was increased by 55% after 11 days of treatment with rufinamide 400 mg twice daily. The exposure of triazolam was reduced by 36%. Higher rufinamide doses may result in a more pronounced induction.
It is recommended that patients treated with substances that are metabolised by the CYP3A4 enzyme system are to be carefully monitored for two weeks at the start of, or after the end of treatment with rufinamide, or after any marked change in the dose. A dose adjustment of the concomitantly administered medicinal product may need to be considered. These recommendations should also be considered when rufinamide is used concomitantly with substances with a narrow therapeutic window such as warfarin and digoxin.
It may not be excluded that rufinamide may also decrease the exposure of substances metabolised by other enzymes, or transported by transport proteins such as P-glycoprotein.
Use in patients with hepatic impairment has not been studied. Caution and careful dose titration is recommended when treating patients with mild to moderate hepatic impairment.
Use in patients with severe hepatic impairment is not recommended.
Co-administration of rufinamide 800 mg twice daily and a combined oral contraceptive (ethinyloestradiol 35 μg and norethindrone 1 mg) for 14 days resulted in a mean decrease in the ethinyl estradiol AUC0-24 of 22% and in norethindrone AUC0-24 of 14%. Studies with other oral or implant contraceptives have not been conducted. Women of child-bearing potential using hormonal contraceptives are advised to use an additional safe and effective contraceptive method.
For patients on rufinamide treatment who have administration of valproate initiated, significant increases in rufinamide plasma concentrations may occur. Therefore, consideration should be given to a dose reduction of rufinamide in patients who are initiated on valproate therapy.
Status epilepticus cases have been observed during treatment with rufinamide in clinical development studies, whereas no such cases were observed with placebo. These events led to rufinamide discontinuation in 20% of the cases. If patients develop new seizure types and/or experience an increased frequency of status epilepticus that is different from the patient’s baseline condition, then the benefit-risk ratio of the therapy should be reassessed.
Rufinamide treatment has been associated with dizziness, somnolence, ataxia and gait disturbances, which could increase the occurrence of accidental falls in this population. Patients and carers should exercise caution until they are familiar with the potential effects of this medicinal product.
Suicidal ideation and behaviour have been reported in patients treated with antiepileptic agents in several indications. A meta-analysis of randomised placebo-controlled trials of anti-epileptic medicinal products has also shown a small increased risk of suicidal ideation and behaviour. The mechanism of this risk is not known and the available data do not exclude the possibility of an increased risk for rufinamide.
Therefore patients should be monitored for signs of suicidal ideation and behaviours and appropriate treatment should be considered. Patients (and caregivers of patients) should be advised to seek medical advice should signs of suicidal ideation or behaviour emerge.
Serious antiepileptic medicinal product hypersensitivity syndrome including DRESS (Drug Reaction with Eosinophilia and Systemic Symptoms) and Stevens-Johnson syndrome have occurred in association with rufinamide therapy. Signs and symptoms of this disorder were diverse; however, patients typically, although not exclusively, presented with fever and rash associated with other organ system involvement. Other associated manifestations included lymphadenopathy, liver function tests abnormalities, and haematuria. As the disorder is variable in its expression, other organ system signs and symptoms not noted here may occur. The antiepileptic drug (AED) hypersensitivity syndrome occurred in close temporal association to the initiation of rufinamide therapy and in the paediatric population. If this reaction is suspected, rufinamide should be discontinued and alternative treatment started. All patients who develop a rash while taking rufinamide must be closely monitored.
In a thorough QT study, rufinamide produced a decrease in QTc interval proportional to concentration. Although the underlying mechanism and safety relevance of this finding is not known, clinicians should use clinical judgment when assessing whether to prescribe rufinamide to patients at risk from further shortening their QTc duration (e.g., Congenital Short QT Syndrome or patients with a family history of such a syndrome).
It has been shown that in the offspring of women with epilepsy, the prevalence of malformations is two to three times greater than the rate of approximately 3% in the general population. In the treated population, an increase in malformations has been noted with polytherapy; however, the extent to which the treatment and/or the illness is responsible has not been elucidated.
Moreover, effective antiepileptic therapy should not be interrupted abruptly, since the aggravation of the illness is detrimental to both the mother and the foetus. AED treatment during pregnancy should be carefully discussed with the treating physician.
Studies in animals revealed no teratogenic effect, but foetotoxicity in the presence of maternal toxicity was observed. The potential risk for humans is unknown.
For rufinamide, no clinical data on exposed pregnancies are available.
Taking these data into consideration, rufinamide should not be used during pregnancy, or in women of childbearing age not using contraceptive measures, unless clearly necessary.
Women of childbearing potential must use contraceptive measures during treatment with rufinamide. Physicians should try to ensure that appropriate contraception is used, and should use clinical judgement when assessing whether oral contraceptives, or the doses of the oral contraceptive components, are adequate based on the individual patients clinical situation.
If women treated with rufinamide plan to become pregnant, the continued use of this product should be carefully weighed. During pregnancy, interruption of an effective antiepileptic can be detrimental to both the mother and the foetus if it results in aggravation of the illness.
It is not known if rufinamide is excreted in human breast milk. Due to the potential harmful effects for the breast-fed infant, breast-feeding should be avoided during maternal treatment with rufinamide.
No data are available on the effects on fertility following treatment with rufinamide.
Rufinamide may cause dizziness, somnolence and blurred vision. Depending on the individual sensitivity, rufinamide may have a minor to major influence on the ability to drive and use machines. Patients must be advised to exercise caution during activities requiring a high degree of alertness, e.g., driving or operating machinery.
The clinical development program has included over 1,900 patients, with different types of epilepsy, exposed to rufinamide. The most commonly reported adverse reactions overall were headache, dizziness, fatigue, and somnolence. The most common adverse reactions observed at a higher incidence than placebo in patients with Lennox-Gastaut syndrome were somnolence and vomiting. Adverse reactions were usually mild to moderate in severity. The discontinuation rate in Lennox-Gastaut syndrome due to adverse reactions was 8.2% for patients receiving rufinamide and 0% for patients receiving placebo. The most common adverse reactions resulting in discontinuation from the rufinamide treatment group were rash and vomiting.
Adverse reactions reported with an incidence greater than placebo, during the Lennox-Gastaut syndrome double-blind studies or in the overall rufinamide-exposed population, are listed below by MedDRA preferred term, system organ class and by frequency.
Frequencies are defined as: very common (≥1/10), common (≥1/100 to <1/10), uncommon (≥1/1,000 to <1/100), rare (≥1/10,000 to <1/1,000).
Common: Pneumonia, Influenza, Nasopharyngitis, Ear infection, Sinusitis, Rhinitis
Uncommon: Hypersensitivity
Common: Anorexia, Eating disorder, Decreased appetite
Common: Anxiety, Insomnia
Very Common: Somnolence, Headache, Dizziness
Common: Status epilepticus, Convulsion, Coordination, Abnormal, Nystagmus, Psychomotor, hyperactivity, Tremor
Common: Diplopia, Vision blurred
Common: Vertigo
Common: Epistaxis
Very Common: Nausea, Vomiting
Common: Abdominal pain upper, Constipation, Dyspepsia, Diarrhoea
Uncommon: Hepatic enzyme increase
Common: Rash, Acne
Common: Back pain
Common: Oligomenorrhoea
Very Common: Fatigue
Common: Gait disturbance
Common: Weight decrease
Common: Head injury, Contusion
In a multicentre, open-label study comparing the addition of rufinamide to any other AED of the investigator’s choice to the existing regimen of 1 to 3 AEDs in paediatric patients, 1 to less than 4 years of age with inadequately controlled LGS, 25 patients, of which 10 subjects were aged 1 to 2 years, were exposed to rufinamide as adjunctive therapy for 24 weeks at a dose of up to 45 mg/kg/day, in 2 divided doses. The most frequently reported TEAEs in the rufinamide treatment group (occurring in ≥10% of subjects) were upper respiratory tract infection and vomiting (28.0% each), pneumonia and somnolence (20.0% each), sinusitis, otitis media, diarrhoea, cough and pyrexia (16.0% each), and bronchitis, constipation, nasal congestion, rash, irritability and decreased appetite (12.0% each). The frequency, type and severity of these adverse reactions were similar to that in children 4 years of age and older, adolescents and adults. Age characterisation in patients less than 4 years was not identified in the limited safety database due to small number of patients in the study.
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