Note: This document contains side effect information about topiramate. Some of the dosage forms listed on this page may not apply to the brand name Topamax.
Common side effects of Topamax include: anxiety, ataxia, confusion, diarrhea, diplopia, dizziness, drowsiness, dysphasia, fatigue, lack of concentration, memory impairment, nausea, nervousness, paresthesia, psychomotor disturbance, speech disturbance, depression, visual disturbance, weight loss, dysgeusia, mood changes, and anorexia. Other side effects include: arthralgia, and asthenia. See below for a comprehensive list of adverse effects.
Applies to topiramate: oral capsule, oral capsule extended release, oral tablet
Along with its needed effects, topiramate (the active ingredient contained in Topamax) 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 topiramate:
Incidence not known
Get emergency help immediately if any of the following symptoms of overdose occur while taking topiramate:
Symptoms of overdose
Some side effects of topiramate 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:
Applies to topiramate: oral capsule, oral capsule extended release, oral tablet
Uncommon (0.1% to 1%): Bradycardia, sinus bradycardia, palpitations, hypotension, orthostatic hypotension, flushing, hot flush
Rare (less than 0.1%): Raynaud's phenomenon
Common (1% to 10%): Alopecia, rash, pruritus
Uncommon (0.1% to 1%): Anhidrosis, hypoesthesia facial, urticaria, erythema, pruritus generalized, rash macular, skin discoloration, dermatitis allergic, swelling face
Rare (less than 0.1%): Stevens-Johnson syndrome, erythema multiforme, skin odor abnormal, periorbital edema, urticaria localized
Frequency not reported: Toxic epidermal necrolysis, oligohidrosis
Postmarketing reports: Bullous skin reactions, pemphigus
Very common (10% or more): Nausea, diarrhea
Common (1% to 10%): Vomiting, constipation, abdominal pain upper, dyspepsia, abdominal pain, dry mouth, stomach discomfort, paresthesia oral, gastritis, abdominal discomfort
Uncommon (0.1% to 1%): Pancreatitis, flatulence, gastroesophageal reflux disease, abdominal pain lower, hypoesthesia oral, gingival bleeding, abdominal distension, epigastric discomfort, abdominal tenderness, salivary hypersecretion, oral pain, breath odor, glossodynia
Uncommon (0.1% to 1%): Erectile dysfunction, sexual dysfunction, renal calculus, intermenstrual bleeding, leucorrhoea, menorrhagia, vaginitis, amenorrhea, urinary tract infections, micturition frequency, urinary incontinence, dysuria
Postmarketing reports: Kidney stones, nephrocalcinosis
Common (1% to 10%): Anemia, epistaxis
Uncommon (0.1% to 1%): Leucopenia, thrombocytopenia lymphadenopathy, white blood cell count decreased, eosinophilia
Rare (less than 0.1%): Neutropenia
Rare (less than 0.1%): Hepatitis, hepatic failure, increase in liver enzymes
Postmarketing reports: Hepatic failure including fatalities
Common (1% to 10%): Hypersensitivity
Frequency not reported: Allergic edema, conjunctival edema
Very common (10% or more): Nasopharyngitis
Frequency not reported: Genital moniliasis
Very common (10% or more): Weight decreased
Common (1% to 10%): Anorexia, decreased appetite, weight increased
Uncommon (0.1% to 1%): Metabolic acidosis, hypokalemia, increased appetite, polydipsia
Rare (less than 0.1%): Acidosis hyperchloremic, blood bicarbonate decreased
Postmarketing reports: Hyperammonemia with and without encephalopathy
Generally, topiramate-induced metabolic acidosis occurs early in treatment; however, it can occur any time. Average decreases of serum bicarbonate of 4 mEq/L have been observed in adults receiving 400 mg/day and pediatrics receiving approximately 6 mg/kg/day. Values below 10 mEq/L have been rarely reported. In adult trials for adjunctive treatment of epilepsy, persistent serum bicarbonate decreases to less than 20 meq/L were reported in 32% of patients receiving 400 mg/day versus 1% of placebo-treated patients. In pediatric trials, adjunctive therapy yielded persistent decreases in serum bicarbonate of 67% for doses of approximately 6 mg/kg/day and 10% for placebo. In monotherapy trials for patients 6 to 15 years, the incidence of persistent decreases in serum bicarbonate was 9% for 50 mg per day and 25% for 400 mg per day. In adult migraine trials, persistent decreases in serum bicarbonate occurred in 44%, 39%, 23%, and 7% of patients receiving 200 mg/day, 100 mg/day, 50 mg/day, and placebo, respectively. In adolescent migraine trials, this was 77%, 27%, 30%, and 9% for those receiving 200 mg/day, 100 mg/day, 50 mg/day, and placebo, respectively.
The incidence of hyperammonemia (above the upper limit of normal) for adolescent patients receiving this drug for migraine prophylaxis was 26%, 14%, and 9% for doses of 100 mg, 50, mg, or placebo, respectively. Hyperammonemia with and without encephalopathy has been reported in the post-marketing period. Hyperammonemia appears to be more common when used concomitantly with valproic acid.
Common (1% to 10%): Arthralgia, muscle spasms, myalgia, muscle twitching, muscular weakness, musculoskeletal chest pain
Uncommon (0.1% to 1%): Joint swelling, musculoskeletal stiffness, flank pain, muscle fatigue
Rare (less than 0.1%): Limb discomfort
Very common (10% or more): Paraesthesia, somnolence, dizziness
Common (1% to 10%): Disturbance in attention, memory impairment, amnesia, cognitive disorder, mental impairment, psychomotor skills impaired, convulsion, coordination abnormal, tremor, lethargy, hypethesia, nystagmus, dysgeusia, balance disorder, dysarthria, intention tremor, sedation
Uncommon (0.1% to 1%): Depressed level of consciousness, grand mal convulsion, visual field defect, complex partial seizures, speech disorder, psychomotor hyperactivity, syncope, sensory disturbance, drooling, hypersomnia, aphasia, repetitive speech, hypokinesia, dyskinesia, dizziness postural, poor quality sleep, burning sensation, sensory loss, parosmia, cerebellar syndrome, dysesthesia, hypogeusia, stupor, clumsiness, aura, ageusia, dysgraphia, dysphasia, neuropathy peripheral, presyncope, dystonia, formication
Rare (less than 0.1%): Apraxia, circadian rhythm sleep disorder, hyperesthesia, hyposmia, anosmia, essential tremor, akinesia, unresponsive to stimuli
Most CNS adverse reactions can be classified into 3 categories: cognitive-related dysfunction (e.g. confusion psychomotor slowing, difficulty with concentration/attention, difficulty with memory, speech, or language problems, particularly word-finding difficulties); psychiatric/behavioral disturbances (e.g. depression or mood problems); and somnolence or fatigue. Most were mild to moderate in severity and frequently occurred in isolation. Rapid titration rate and higher initial dose was associated with a higher occurrence.
Common (1% to 10%): Vision blurred, diplopia, visual disturbance
Uncommon (0.1% to 1%): Visual acuity reduced, scotoma, myopia, abnormal sensation in eye, dry eye, photophobia, blepharospasm, lacrimation increased, photopsia, mydriasis, presbyopia
Rare (less than 0.1%): Blindness unilateral, blindness transient, glaucoma, accommodation disorder, altered visual depth perception, scintillating scotoma, eyelid edema, night blindness, amblyopia
Frequency not reported: Angle closure glaucoma, maculopathy, eye movement disorder
Very common (10% or more): Fatigue
Common (1% to 10%): Vertigo, tinnitus, ear pain pyrexia, asthenia, irritability, gait disturbance, feeling abnormal, malaise
Uncommon (0.1% to 1%): Deafness, deafness unilateral, deafness neurosensory, ear discomfort, hearing impaired, hyperthermia, thirst, influenza like illness, sluggishness, peripheral coldness, feeling drunk, feeling jittery, tandem gait test abnormal
Rare (less than 0.1%): Face edema, calcinosis, learning disability
Frequency not reported: Hypothermia, hyperthermia (associated with oligohidrosis)
Very common (10% or more): Somnolence (15%), memory loss (10%), depression
Common (1% to 10%): Depression, difficulty with concentration/attention, anxiety psychomotor slowing, altered mood, confusion, cognitive difficulty, bradyphrenia, decreased libido, expressive language disorder, disorientation, aggression, aggression, anger, abnormal behavior
Uncommon (0.1% to 1%): Suicidal ideation, suicide attempt, hallucination, psychotic disorder, hallucination auditory, hallucination visual, apathy, lack of spontaneous speech, sleep disorder, affect lability, restlessness, crying, dysphemia, euphoria, paranoia, perseveration, panic attack, tearfulness, reading disorder, flat affect, thinking abnormal, listlessness, middle insomnia, distractibility, early morning awakening, panic reaction, elevated mood
Rare (less than 0.1%): Mania, panic disorder, feelings of despair, hypomania
Antiepileptic drugs increased the risk of suicidal thoughts or behaviors when taken for any indication. Pooled analyses of 199 placebo-controlled clinical trials of 11 different antiepileptic drugs showed patients on antiepileptics had approximately twice the risk compared to placebo. In these trials (median duration 12 weeks; most less than 24 weeks), the estimated incidence rate of suicidal behavior or ideation was 0.43% compared to 0.24% which represents an increase of approximately 1 case for every 530 patients treated.
Common (1% to 10%): Nephrolithiasis, pollakiuria, dysuria
Uncommon (0.1% to 1%): Calculus urinary, urinary incontinence, hematuria, incontinence, micturition urgency, renal colic, renal pain
Rare (less than 0.1%): Calculus ureteric, renal tubular acidosis
In clinical trials, 1.5% of adult patients receiving this drug developed kidney stones (approximately 2 to 4 times more than expected). The incidence was higher in men. Kidney stone have been reported in pediatric patients taking this drug for epilepsy or migraine.
Common (1% to 10%): Bronchitis, rhinitis, dyspnea, epistaxis, nasal congestion, rhinorrhea, cough
Uncommon (0.1% to 1%): Dyspnea exertional, paranasal sinus hypersecretion, dysphonia
Medically reviewed by BestRx Medical Team Last updated on 1/1/2020.
Source: Drugs.com Topamax