Common side effects include nausea, stomach pain, loss of appetite, poor coordination, increased hair growth, and enlargement of the gums. Potentially serious side effects include sleepiness, self harm, liver problems, bone marrow suppression, low blood pressure, and toxic epidermal necrolysis. There is evidence that use during pregnancy results in abnormalities in the baby. Its use appears to be safe during breastfeeding. Alcohol may interfere with the medication's effects. Heart and blood vessels Severe low blood pressure and abnormal heart rhythms can be seen with rapid infusion of IV<unk> . IV infusion should not exceed 50 mg/min in adults or 1–3 mg/kg/min (or 50 mg/min, whichever is slower) in children. Heart monitoring should occur during and after IV infusion. Due to these risks, oral<unk>  should be used if possible. Neurological At therapeutic doses,<unk>  may produce nystagmus on lateral gaze. At toxic doses, patients experience vertical nystagmus, double vision, sedation, slurred speech, cerebellar ataxia, and tremor. If<unk>  is stopped abruptly, this may result in increased seizure frequency, including status epilepticus.<unk>  may accumulate in the cerebral cortex over long periods of time which can cause atrophy of the cerebellum. The degree of atrophy is related to the duration of<unk>  treatment and is not related to dosage of the medication.<unk>  is known to be a causal factor in the development of peripheral neuropathy. Blood Folate is present in food in a polyglutamate form, which is then converted into monoglutamates by intestinal conjugase to be absorbed by the jejunum.<unk>  acts by inhibiting this enzyme, thereby causing folate deficiency, and thus megaloblastic anemia. Other side effects may include: agranulocytosis, aplastic anemia, decreased white blood cell count, and a low platelet count. Pregnancy<unk>  is a known teratogen, since children exposed to<unk>  are at a higher risk of birth defects than children born to women without epilepsy and to women with untreated epilepsy. The birth defects, which occur in approximately 6% of exposed children, include neural tube defects, heart defects and craniofacial abnormalities. The syndrome consists of craniofacial anomalies (broad nasal bridge, cleft lip and palate, smaller than normal head). The effect on IQ cannot be determined as no study involves<unk>  as monotherapy, however poorer language abilities and delayed motor development were associated with<unk>  use during pregnancy. This syndrome resembles the well-described fetal alcohol syndrome and has also been called the "fetal hydantoin syndrome". Some recommend avoiding polytherapy and maintaining the minimal dose possible during pregnancy, but acknowledge that current data fails to demonstrate a dose effect on the risk of birth defects. Data now being collected by the Epilepsy and Antiepileptic Drug Pregnancy Registry may one day answer this question definitively. Cancer There is no good evidence to suggest that<unk>  is a human carcinogen. Mouth<unk>  has been associated with drug-induced gingival enlargement (overgrowth of the gums), probably due to above-mentioned folate deficiency; indeed, evidence from a randomized controlled trial suggests that folic acid supplementation can prevent gingival enlargement in children who take<unk> . Plasma concentrations needed to induce gingival lesions have not been clearly defined. Effects consist of the following: bleeding upon probing, increased gingival exudate, pronounced gingival inflammatory response to plaque levels, associated in some instances with bone loss but without tooth detachment. Skin Hypertrichosis, Stevens–Johnson syndrome, purple glove syndrome, rash, exfoliative dermatitis, itching, excessive hairiness, and coarsening of facial features can be seen in those taking<unk> .<unk>  therapy has been linked to the life-threatening skin reactions Stevens–Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). These conditions are significantly more common in patients with a particular HLA-B allele, HLA-B*1502. This allele occurs almost exclusively in patients with ancestry across broad areas of Asia, including South Asian Indians.<unk>  is primarily metabolized to its inactive form by the enzyme CYP2C9. Variations within the CYP2C9 gene that result in decreased enzymatic activity have been associated with increased<unk>  concentrations, as well as reports of drug toxicities due to these increased concentrations. The U.S. Food and Drug Administration (FDA) notes on the<unk>  drug label that since strong evidence exists linking HLA-B*1502 with the risk of developing SJS or TEN in patients taking carbamazepine, consideration should be given to avoiding<unk>  as an alternative to carbamazepine in patients carrying this allele. Immune system<unk>  has been known to cause drug-induced lupus.<unk>  is also associated with induction of reversible IgA deficiency. Psychological<unk>  may increase risk of suicidal thoughts or behavior. People on<unk>  should be monitored for any changes in mood, the development or worsening depression, and/or any thoughts or behavior of suicide. Some case reports of acute<unk>  psychosis were already described. Bones Chronic<unk>  use has been associated with decreased bone density and increased bone fractures.<unk>  induces metabolizing enzymes in the liver. This leads to increased metabolism of vitamin D, thus decreased vitamin D levels. Vitamin D deficiency, as well as low calcium and phosphate in the blood cause decreased bone mineral density.
Phenytoin
Mephenytoin
Carbamazepine
Mesuximide
Propazepine
Levetiracetam
Phenobarbital
Oxcarbazepine