Clinical effects and toxicokinetic evaluation following massive topiramate ingestion

Topiramate-Induced Coma in a 39-Year-Old Female Patient: Burst Suppression on EEG

Reported cases of topiramate ingestion resulting in coma and generalized convulsive status epilepticus are very rare. Such a phenomenon of a relatively safe antiepileptic drug (AED) causing serious neurological compromise should be carefully reviewed. A 39-year-old female with a history of uncontrolled epilepsy, migraine headaches, hypothyroidism, obsessive-convulsive disorder, and depression presented with generalized tonic-clonic seizures that progressed to status epilepticus and coma thereafter. She was intubated due to a depressed level of consciousness and transferred afterward to our hospital. Electroencephalography (EEG) demonstrated a burst suppression pattern without receiving any sedating agents. The level of consciousness improved on the fourth day, and she achieved complete neurological recovery by the sixth day of hospitalization. She was offered AEDs and supportive therapy during her admission. Upon further investigation into the cause of her seizures, it was discovered that she had ingested a large dose of topiramate in a suicide attempt.

Topiramate intoxications & hemodialysis - Literature review and the first case report of a massive suicidal intoxication treated with hemodialysis

Background

Topiramate is an anticonvulsant from sulfamate-substituted monosaccharides that is increasingly used to treat migraines. Serious topiramate intoxications have been described. Unfortunately, indications for and the effect of interventions, including hemodialysis, in severe intoxications seem expert-based and lack empirical evidence. We aim to review the literature on topiramate intoxication cases and to describe the first topiramate intoxication with toxicokinetic data following treatment with hemodialysis.

Methods

A literature review was conducted using the PubMed database. Included articles were reviewed for symptoms; management, including acute hemodialysis; toxicokinetic data; and outcomes.

Results

We found 61 hits in the PubMed database and checked 392 references in the snowball search; 22 were included for data extraction, reporting 29 cases. The majority of the patients were female (n = 23/29, 79%), ranging in age from 2 to 44 years (median 21). The ingested topiramate amount ranged from 175 to 40,000 mg (usual maintenance dose of 50 mg BID and a general maximum of 500 mg BID). Topiramate concentrations were reported in eight cases, ranging from 3.7 to 356.6 mg/L (for reference, the therapeutic range is 2-30 mg/L). Serious topiramate intoxications can result in seizures, coma, hemodynamic instability and severe metabolic acidosis. In no single case was hemodialysis used.

Conclusion

Serious symptoms of topiramate intoxications exist, and hemodialysis is used infrequently. If symptoms are refractory to symptomatic treatment, hemodialysis can reduce topiramate concentrations and symptomatology.

Iatrogenic topiramate poisoning in an ICU patient: Focus on topiramate peak time prolongation

A 35-year-old man with generalized insults was admitted to the intensive care unit because of third-line treatment of persistent epileptic insults with antiepileptic drug therapy. Topiramate was added on top of his outpatient regimen in combination with intravenous antiepileptic drugs. Miscommunication and inappropriate topiramate dosing (2,500 mg twice) resulted in an acute topiramate intoxication. Toxicokinetic assessment showed toxic serum topiramate concentration of 55 mg/L and a dose-dependent shift of peak time t_max. According to our modulations, t_max follows Y = 0.0009X + 2.65, where X is the topiramate dose. Our results have important implications for effectiveness of gut decontamination modalities.

Normal anion gap metabolic acidosis secondary to topiramate intake: case report

Introducción. El topiramato es un medicamento que se usa en el tratamiento de varios tipos de epilepsia y como profilaxis en casos de cefalea migrañosa. Entre sus mecanismos de acción, la inhibición de la anhidrasa carbónica en el riñón desencadena la excreción de orina alcalina ocasionando acidosis metabólica. Presentación del caso. Paciente femenino de 17 años procedente de la Ciudad de México con antecedente de consumo de topiramato, quetiapina y sertralina para manejo de síndrome depresivo, quien desarrolla acidosis metabólica de anión restante normal secundaria a ingesta de topiramato. La joven requiere soporte ventilatorio invasivo por deterioro del estado de conciencia y síndrome de dificultad respiratoria y presenta adecuada respuesta a manejo con catártico y bicarbonato sin compromiso renal y sin secuelas neurológicas. Discusión. La acidosis metabólica es la alteración ácido base más frecuente en la práctica clínica. La diferencia entre cationes y aniones medibles, conocida como anión restante o brecha aniónica, permite clasificar este tipo de acidosis. Las pérdidas de bicarbonato o trastornos de la función tubular renal generan acidosis de anión restante normal; por el contrario, la acidosis causada por sobreproducción de ácido endógeno o por insuficiencia renal genera anión restante elevado. El topiramato es una causa poco conocida de acidosis metabólica con anión restante normal; al inhibir la anhidrasa carbónica, se ocasiona una acidosis tubular renal mixta o tipo 3 debido a una incapacidad de secreción de hidrogeniones en el túbulo colector y una limitación en la reabsorción del bicarbonato en el túbulo proximal. Conclusión. El topiramato en dosis terapéutica o en sobredosis puede generar acidosis metabólica de anión restante normal debido a la inhibición de la anhidrasa carbónica a nivel renal. Se trata de un cuadro reversible en el cual el manejo con bicarbonato ha mostrado buenos resultados clínicos.

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

Levetiracetam and topiramate are newer anticonvulsants, which is why international data on overdoses of these drugs are lacking. Only a few mild adverse reactions have been noted. These anticonvulsants have been the drug of choice for neurologists. Despite their wide usage, there is a dearth of literature on symptoms and signs of their toxicity. Presented here is the case of a 21-year-old female who overdosed twice on levetiracetam and topiramate. The woman was admitted and discharged after the first overdose. Ten days later, she took multiple tablets of both drugs and was seen again. Amazingly, the woman went home after the incident with no complications at all.

Treatment of Generalized Convulsive Status Epilepticus in Pediatric Patients

Generalized convulsive status epilepticus (GCSE) is one of the most common neurologic emergencies and can be associated with significant morbidity and mortality if not treated promptly and aggressively. Management of GCSE is staged and generally involves the use of life support measures, identification and management of underlying causes, and rapid initiation of anticonvulsants. The purpose of this article is to review and evaluate published reports regarding the treatment of impending, established, refractory, and super-refractory GCSE in pediatric patients.

Enteral topiramate in a pediatric patient with refractory status epilepticus: a case report and review of the literature

We describe the use of topiramate in a healthy 12-year-old (88-kg) male who developed refractory generalized convulsive status epilepticus. Seizures persisted despite aggressive use of benzodiazepines (intravenous lorazepam; oral clorazepate), barbiturates (i.e., phenobarbital, pentobarbital), and hydantoins. The child's seizures were controlled with nasogastrically administered topiramate in doses up to 500 mg twice daily (11.4 mg/kg/day). The patient did not display any clinical or laboratory signs of metabolic acidosis while receiving topiramate. Topiramate should be considered as a treatment option in refractory status epilepticus.

Topiramate: safety and efficacy of its use in the prevention and treatment of migraine

Migraine headaches are typically episodic in nature and may affect nearly 10% of the population. In addition to treatment, prevention of subsequent episodes or progression to a chronic migraine state is an important therapeutic area. Topiramate is a centrally acting medication approved for both the prevention of seizures and migraine headache. At this time, the exact mechanism of how topiramate assists in migraine prevention is unknown. Several large randomized, controlled trials have aided in establishing topiramate's role in migraine prevention. Despite a favorable pharmacokinetic and adverse effect profile established in clinical trials, several additional studies, case reports and toxicology reports have demonstrated topiramate as a cause of cognitive and behavioural changes. The use of topiramate in migraine prevention can improve a patient's quality of life and is a cost-effective option for migraine prevention.