Adverse reactions : תופעות לוואי

4.8.     Undesirable effects

Summary of the safety profile
Visual field defects ranging from mild to severe have been reported frequently in patients receiving vigabatrin.
Severe cases are potentially disabling. The onset is usually after months to years of vigabatrin therapy. Pooled data from prevalence surveys suggest that as many as 1/3 of patients receiving vigabatrin therapy develop visual field defects (see also section 4.4).

Approximately 50% of patients in controlled clinical studies have experienced undesirable effects during vigabatrin treatment. In adults, these were mostly central nervous system-related such as sedation, drowsiness, fatigue and impaired concentration. However, in children, excitation or agitation is frequent. The incidence of these undesirable effects is generally higher at the beginning of treatment and decreases with time.

As with other antiepileptic drugs, some patients may experience an increase in seizure frequency, including status epilepticus with vigabatrin. Patients with myoclonic seizures may be particularly liable to this effect.
New-onset myoclonus and exacerbation of existing myoclonus may occur in rare cases.

Tabulated list of adverse reactions

Undesirable effects ranked under headings of frequency are listed below, using the following convention: 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); very rare (<1/10,000); not known (cannot be estimated from the available data).
Very common Common                Uncommon Rare                       Very rare        Not known Blood and                           anaemia lymphatic system disorders
Psychiatric                         agitation,        hypomania,    suicide attempt       hallucination disorders*                          aggression,       mania,
nervousness,      psychotic depression,       disorder paranoid reaction insomnia .
Nervous system      somnolence      speech disorder, coordination encephalopathy**        optic neuritis   Cases of brain MRI disorders                           headache,        abnormal                                              abnormalities have dizziness,       (ataxia)                                              been reported, paraesthesia,                                                          intramyelinic disturbance in                                                         oedema attention and                                                          (particularly in memory                                                                 infants) (see impairment,                                                            sections 4.4 and mental                                                                 5.3).
impairment
(thought disturbance),
tremor
Eye disorders       visual field    vision blurred,                 retinal disorder    optic atrophy      Reduced visual defect          diplopia,                       (mainly peripheral)                    acuity nystagmus
Gastrointestinal                    nausea,
disorders                           vomiting,
abdominal pain
Hepato-biliary                                                                            hepatitis disorders
Skin and                            alopecia.         rash          angioedema, subcutaneous                                                        urticaria tissue disorders
Musculoskeletal     arthralgia and connective tissue disorders
General Disorders fatigue           oedema,
and administration                  irritability site conditions
Investigations***                   weight increased


*Psychiatric reactions have been reported during vigabatrin therapy. These reactions occurred in patients with and without a psychiatric history and were usually reversible when vigabatrin doses were reduced or gradually discontinued (see section 4.4). Depression was a common psychiatric reaction in clinical trials but seldom required discontinuation of vigabatrin.

**Rare reports of encephalopathic symptoms such as marked sedation, stupor and confusion in association with nonspecific slow wave activity on electroencephalogram have been described soon after the initiation of vigabatrin treatment. Such reactions have been fully reversible following dose reduction or discontinuation of vigabatrin (see section 4.4).

***Laboratory data indicate that vigabatrin treatment does not lead to renal toxicity. Decreases in ALT and AST, which are considered to be a result of inhibition of these aminotransferases by vigabatrin, have been observed.
Paediatric population

Psychiatric disorders

Very common: excitation, agitation
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. any suspected adverse events should be reported to the Ministry of Health according to the National Regulation by using an online form https://sideeffects.health.gov.il
In addition, you can report to Padagis via the following address: Padagis.co.il.