Topiramate (toe PYRE a mate) has been approved by the FDA as initial monotherapy for focal-onset or primary generalized tonic-clonic seizures in patients 2 years and older, and as adjunctive therapy for focal-onset seizures, primary generalized tonic-clonic seizures, or seizures associated with Lennox-Gastaut syndrome in patients 2 years of age and older.
Your epilepsy treatment should always be discussed with your healthcare provider before use. Based on their judgment and knowledge, a drug may be prescribed for other epilepsy types not included in the indications. For more information, please see the prescribing information.
Topiramate is available as a tablet and as a sprinkle capsule taken whole and with or without food. The sprinkle capsule can be added on top of a teaspoon of soft food and swallowed immediately, not chewed.
Other considerations may influence whether you should take topiramate. Tell your healthcare provider if you:
Do not stop taking topiramate suddenly unless directed to do so by your healthcare provider.
As with all antiseizure medications, topiramate should be withdrawn gradually to minimize the risk of causing or worsening seizures or status epilepticus. You should not stop using topiramate suddenly unless your healthcare provider tells you to stop the medicine because of a serious side effect.
Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.
Taking topiramate with certain other medicines may cause side effects or affect how well they work. Do not start or stop other medicines without talking to your healthcare provider. Especially tell your healthcare provider if you take: valproic acid and any medicines that impair or decrease your thinking, concentration, or muscle coordination.
Topiramate can cause fetal harm when administered to a pregnant individual. Data from pregnancy registries indicate that infants exposed to topiramate in utero have an increased risk for cleft lip and/or cleft palate (oral clefts) and for being small for gestational age (SGA). However, having a seizure during pregnancy could harm both the pregnant individual and the baby. Tell your healthcare provider right away if you become pregnant. Do not start or stop taking seizure medication during pregnancy without your healthcare provider’s advice.
If you become pregnant while taking topiramate, talk to your healthcare provider about registering with the North American Antiepileptic Drug (NAAED) Pregnancy Registry. The purpose of this registry is to collect information about the safety of antiseizure medicine during pregnancy. You can enroll in this registry by calling 1-888-233-2334.
Topiramate is present in breast milk. It is unknown if there are effects on milk production. Talk to your healthcare provider about the risks. Diarrhea and somnolence have been reported in breastfed infants whose pregnant people receive topiramate treatment. Your healthcare provider will consider the developmental and health benefits of breastfeeding along with your need for topiramate and the potential effect on the infant from topiramate or from your epilepsy.
People of childbearing potential who are not planning a pregnancy should use effective contraception because of the risks of oral clefts and SGA. Topiramate may decrease the effectiveness of hormonal contraceptives, including birth control pills, injections, implants, skin patches, and vaginal rings. To prevent pregnancy while using topiramate, use a barrier form of birth control: condom, diaphragm, cervical cap, or contraceptive sponge.
Topiramate is approved by the FDA because it is safe and effective for the majority of people who take it. However, there are risks associated with all medicines. Some side effects caused by topiramate can be very serious, and even life-threatening. It is important to be informed about these serious reactions and to be aware of their symptoms.
The most common side effects that were reported in studies of topiramate are paresthesia, anorexia (eating disorder associated with low body weight), weight loss, speech disorders/related speech problems, fatigue, dizziness, drowsiness (somnolence), nervousness, psychomotor (conscious movement) slowing, abnormal vision, and fever.
Rare but life-threatening reactions involving the immune system or multi-organ hypersensitivity, which can cause serious blood or liver problems have been reported with topiramate use. You may or may not have a rash with these types of reactions. Call your healthcare provider right away if you experience fever, frequent infections, severe muscle pain, swelling of your face, eyes, lips, or tongue, swollen lymph glands, unusual bruising or bleeding, weakness, fatigue, yellowing of your skin, or the white part of your eyes, trouble walking or seeing, seizures happening more often, or pain/tenderness in the area toward the top of your stomach (enlarged liver/spleen).
Studies have found that people who take antiseizure medications including topiramate may have suicidal thoughts or behaviors, which occur in approximately 1 in 500 patients. If you experience any thoughts or impulses to hurt yourself, you should contact your healthcare provider immediately.
Serious skin reactions (Stevens-Johnson syndrome [SJS] and Toxic Epidermal Necrolysis [TEN]) have been reported in patients receiving topiramate. Topiramate should be discontinued at the first sign of a rash unless the rash is clearly not drug-related. If signs or symptoms suggest SJS/TEN, use of this drug should not be resumed and alternative therapy should be considered.
A syndrome consisting of acute myopia (nearsightedness) associated with secondary angle-closure glaucoma has been reported in adult and pediatric patients receiving topiramate. Symptoms include acute onset of decreased visual acuity and/or ocular pain. Ophthalmologic findings can include myopia, anterior chamber shallowing, ocular hyperemia (redness), and increased intraocular (inside eye) pressure. Mydriasis (pupil dilation) may or may not be present. This syndrome may be associated with supraciliary effusion (fluid between a specific section in the eye) resulting in anterior displacement of the lens and iris, with secondary angle closure glaucoma. Symptoms typically occur within 1 month of initiating topiramate therapy. The primary treatment to reverse symptoms is the discontinuation of topiramate as rapidly as possible, according to the judgment of the treating physician. If left untreated, the intraocular pressure could lead to permanent vision loss.
Visual field defects (independent of elevated intraocular pressure) have been reported in clinical trials and postmarketing experience in patients receiving topiramate. In clinical trials, most of these events were reversible after topiramate discontinuation. If visual problems occur at any time during topiramate treatment, consideration should be given to discontinuing the drug.
Oligohidrosis (decreased sweating), infrequently resulting in hospitalization, has been reported in association with topiramate use. Decreased sweating and an elevation in body temperature above normal (hyperthermia) were characterized in these cases. Some of the cases were reported after exposure to elevated environmental temperatures. The majority of the reports have been in pediatric patients.
Topiramate can cause metabolic acidosis (excess acid in body fluids). Symptoms of acute or chronic metabolic acidosis may include hyperventilation (abnormal rapid breathing), nonspecific symptoms such as fatigue and anorexia (eating disorder associated with low body weight), or more severe conditions including cardiac arrhythmias (abnormal heart rhythm) or stupor. Chronic, untreated metabolic acidosis may increase the risk for too much calcium in the kidneys or kidney stones (nephrolithiasis or nephrocalcinosis), and may also result in osteomalacia (referred to as rickets in pediatric patients) and/or osteoporosis with an increased risk for fractures. Chronic metabolic acidosis in pediatric patients may also reduce growth rates, which may decrease the maximal height achieved.
Topiramate can cause cognitive/neuropsychiatric adverse reactions. The most frequent of these can be classified into 3 general categories: 1) Cognitive-related dysfunction (e.g., confusion, psychomotor slowing, difficulty with concentration/attention, difficulty with memory, speech or language problems, particularly word-finding difficulties); 2) Psychiatric/behavioral disturbances (e.g., depression or mood problems); and 3) Drowsiness (somnolence) or fatigue.
Topiramate treatment can cause hyperammonemia (high ammonia in the body) with or without encephalopathy (brain malfunctions). The risk for hyperammonemia with topiramate appears dose-related. Hyperammonemia has been reported more frequently when topiramate is used concomitantly with valproic acid. Postmarketing cases of hyperammonemia with or without encephalopathy have been reported with topiramate and valproic acid in patients who previously tolerated either drug alone.
Topiramate increases the risk of kidney stones. As in the general population, the incidence of stone formation among topiramate-treated patients was higher in men. Kidney stones have also been reported in pediatric patients taking topiramate for epilepsy. Avoid use with other carbonic anhydrase inhibitors, drugs causing metabolic acidosis, or if you are on a ketogenic diet.
Hypothermia (lower body temperature) has been reported with and without hyperammonemia during topiramate treatment with concomitant valproic acid use.