Applies to cenobamate: oral tablet.

Serious side effects of Cenobamate

Along with its needed effects, cenobamate may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking cenobamate:

Less common

• Fast, irregular, pounding, or racing heartbeat or pulse

Incidence not known

• Black, tarry stools
• bloody or cloudy urine
• changes in behavior
• chest pain or discomfort
• chills
• confusion
• cough
• dark urine
• difficulty in breathing
• discouragement
• drowsiness
• false or unusual sense of well-being
• fast heartbeat
• feeling sad or empty
• fever
• general tiredness and weakness
• headache
• irritability
• lack of appetite
• light-colored stools
• loss of interest or pleasure
• muscle pain
• nausea and vomiting
• painful or difficult urination
• rash sore throat
• sores, ulcers, or white spots on the lips or in the mouth
• swelling of the face, feet, or lower legs
• swollen glands
• swollen, painful, or tender lymph glands in the neck, armpit, or groin
• thoughts of killing oneself
• tiredness
• trouble concentrating
• trouble sleeping
• unusual tiredness or weakness
• unusual weight gain
• upper right abdominal or stomach pain
• yellow eyes and skin

Other side effects of Cenobamate

Some side effects of cenobamate may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

• Blurred vision
• change in walking and balance
• changes in patterns and rhythms of speech
• clumsiness or unsteadiness
• constipation
• dizziness or lightheadedness
• double vision
• feeling of constant movement of self or surroundings
• seeing double
• sensation of spinning
• shakiness and unsteady walk
• sleepiness or unusual drowsiness
• slurred speech
• trouble in speaking
• uncontrolled eye movements
• unsteadiness, trembling, or other problems with muscle control or coordination

Less common

• Abdominal or stomach pain
• acid or sour stomach
• back pain
• belching
• change in taste
• decreased appetite
• diarrhea
• dry mouth
• heartburn
• impaired memory
• indigestion
• itching skin
• lack or loss of strength
• loss of taste
• muscle aches
• problems with speech or speaking
• sore throat
• stomach discomfort or upset
• stuffy or runny nose

For Healthcare Professionals

Applies to cenobamate: oral tablet.

General

The most commonly reported adverse reactions have included somnolence, dizziness, fatigue, diplopia, and headache.^[Ref]

Nervous system

During clinical trials, at least one adverse reaction related to somnolence and fatigue (i.e., asthenia, malaise, hypersomnia, sedation, and lethargy) was reported in 31%, 36%, and 57% of patients receiving 100 mg/day, 200 mg/day, and 400 mg/day, respectively, compared to 19% of patients who received placebo. Reactions were serious in 0.4% drug-treated patients (compared to no patients who received placebo). Discontinuations due to somnolence and fatigue-related adverse reactions occurred in 2% patients on therapy compared to 1% of patients who received placebo.

During clinical trials, at least one adverse reaction related to dizziness and disturbance in gait and coordination (i.e., dizziness, vertigo, balance disorder, ataxia, nystagmus, gait disturbance, and abnormal coordination) was reported in 21%, 31%, and 52% of patients receiving 100 mg/day, 200 mg/day, and 400 mg/day, respectively, compared to 18% of patients who received placebo. Reactions were serious in 2% drug-treated patients (compared to no patients who received placebo). Discontinuations due to dizziness and disturbance in gait and coordination occurred in 5% patients on therapy compared to 1% of patients who received placebo.

During clinical trials, at least one adverse reaction related to cognitive dysfunction (i.e., memory impairment, disturbance in attention, amnesia, confusional state, aphasia, speech disorder, slowness of thought, disorientation, and psychomotor retardation) was reported in 6%, 6%, and 9% of patients receiving 100 mg/day, 200 mg/day, and 400 mg/day, respectively, compared to 2% of patients who received placebo. Discontinuations due to cognitive dysfunction related event occurred in 0.4% patients on therapy compared to 0% of patients who received placebo.

Very common (10% or more): Somnolence (37%), dizziness (33%), headache (12%), fatigue (24%)

Common (1% to 10%): Vertigo, balance disorder, gait disturbance, dysarthria, nystagmus, ataxia, aphasia, asthenia, dysgeusia, memory impairment, migraine, sedation, tremor

Psychiatric

Common (1% to 10%): Confusional state, euphoric mood, irritability, suicidal ideation

Immunologic

Frequency not reported: Drug reaction with eosinophilia and systemic symptoms (DRESS)

During clinical trials, DRESS was reported including 1 fatality. The patient who died had been titrated rapidly. This finding does not establish that the risk is prevented by a slower titration, however it is recommended to follow the dosage and titration dosing guidelines.

Ocular

Very common (10% or more): Diplopia (15%)

Common (1% to 10%): Blurred vision

During clinical trials, at least one adverse reaction related to visual impairment (i.e., diplopia, blurred vision, and impaired vision) was reported in 9%, 9%, and 18% of patients receiving 100 mg/day, 200 mg/day, and 400 mg/day, respectively, compared to 2% of patients who received placebo. Discontinuations due to cognitive dysfunction related event occurred in 0.5% patients on therapy compared to 0% of patients who received placebo.

Cardiovascular

In a QT study, a higher percentage of subjects taking this drug at 200 mg and 500 mg had QT shortening of greater than 20 msec compared to placebo (31% vs 6%) and (66% vs 17%), respectively. Reductions of the QTc interval below 300 msec were not observed.

Common (1% to 10%): Palpitations

Frequency not reported: QTc shortening

Metabolic

Increased potassium levels (greater than 5 meq/L) occurred in 17% of patients (compared to 7% receiving placebo). A dose-related occurrence was observed in 1 trial with 8.3%, 9.1%, and 10.8% of patients receiving 100, 200, or 400 mg/day reporting at least one potassium value greater than 5 meq/L. Two patients had a maximum potassium value of 5.9 meq/L.

Very common (10% or more): Hyperkalemia (17%)

Common (1% to 10%): Decreased appetite, weight decreased

Gastrointestinal

Common (1% to 10%): Nausea, constipation, diarrhea, vomiting, dry mouth, abdominal pain, dyspepsia

Frequency not reported: Appendicitis

During clinical trials, 2.9 cases of appendicitis/1000 patient-years of exposure occurred; this is in excess of the expected background rate in the general population.

Musculoskeletal

Common (1% to 10%): Back pain, musculoskeletal chest pain

Genitourinary

Common (1% to 10%): Urinary tract infection, pollakiuria, dysmenorrhea

Respiratory

Common (1% to 10%): Nasopharyngitis, pharyngitis, hiccups, dyspnea

Other

Common (1% to 10%): Head injury

Dermatologic

Common (1% to 10%): Pruritus, popular rash

Hepatic

The maximum ALT elevation was 7.6 times the upper limit (7.6 x ULN) of normal and this occurred in patients receiving 400 mg/day. ALT elevations of 3 x ULN occurred in 0.9%, 1.8%, and 2.7% of patients receiving 100, 200, and 400 mg/day, respectively.

Common (1% to 10%): Elevated transaminases