Acute topiramate overdose – clinical manifestations

Abstract

The clinical manifestations of acute poisonings with topiramate ranged from asymptomatic to severe, but no distant sequelae or fatalities were observed. The course of acute poisoning seems to be more severe in patients who were not previously treated with topiramate.

A fatal intoxication case involving topiramate

“…The most prevalent side effects of topiramate are CNS effects such as psychomotor slowing, cognitive impairment, dizziness, ataxia, and behavioural changes [13][14][15][16]. Adverse events and encephalopathic features may become prominent at plasma concentrations >20 mg/L [12].…”

Levetiracetam and topiramate poisoning: Two overdoses on those drugs with no lasting effects

“…It is indicated as a monotherapy or adjunctive therapy to alleviate partial seizures, generalized tonic-clonic seizures, and Lennox-Gastaut syndrome. Topiramate is also being used in the treatment of migraines, cluster headaches, essential tremors, binge eating disorders, acute mania, Tourette's syndrome, neuropathic pain, bipolar disorder, alcohol dependence, excess body weight, and smoking (4,5). Structurally, topiramate is unrelated to other anticonvulsants and acts by multiple neurostabilizing processes (6,7).…”

Topiramate, a concealed cause of severe metabolic acidosis

“…A 17 year old lady with suicidal intake of 800 mg of topiramate developed incoherence, confusion, disorientation, and speech impairments, but eventually had full resolution of symptoms within ~24 hours [10]. Most patients with topiramate toxicity recover relatively quickly with just supportive treatment [4,5,10,11,13]. In our literature search we found only two cases of fatal topiramate toxicity.…”

“…Less commonly a variety of gastrointestinal symptoms have also been described [6]. Several reports describe toxicity at varying doses of ingestion when used for migraine and epilepsy (Table 2) [4,5,[7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Based on a retrospective review of 567 cases of topiramate toxicity (during 2000-2001), the American Association of Poison Control revealed that: 39% were adults, mild mental status changes were common, and severe respiratory depression or persistent NAGMA were infrequent yet other reports confirm their occurrence [5,[10][11][12].…”

“…Common adverse effects from topiramate are neurological, including paresthesia, somnolence, fatigue, dizziness, mood and memory impairment, lack of concentration, confusion, headache, psychomotor retardation, agitation, cognitive dysfunction, ataxia, pain, as well as sensory and speech disturbances [2,[4][5][6]. Less commonly a variety of gastrointestinal symptoms have also been described [6].…”