Generalized seizures

Absence seizures generally occur in young children or adolescents and exhibit a sudden onset, interruption of ongoing activities, a blank stare, and possibly a brief upward rotation of the eyes. Absence seizures have a characteristic two to four cycle/second spike and slow-wave EEG pattern. 

Take at bedtime if seizures generally occur at night, and during the day if attacks are diurnal. Start treatment with a small dose and gradually increase over 4 or 5 days until optimum dosage is determined. 

Phenobarbital is still used for the management of partial seizures, generalized tonic-clonic seizures and for the control of status epilepticus. However because of its low therapeutic index and the possibility of dependence, phenobarbital has largely been displaced by other anticonvulsants. For newborns phenobarbital is often the drug of first choice. If given together with sodium valproate the metabolism of phenobarbital may be inhibited while in combination with carbamazepine the serum concentrations of carbamazepine will be reduced due to enzyme induction by phenobarbital. 

Benzodiazepines and barbiturates are used as anticonvulsant drugs in the treatment of epilepsy. Epilepsy, a medical disorder characterized by recurrent seizures, has many different forms. The four most common seizure types are generalized tonic-clonic seizures (old name grand mal seizures), generalized absence seizures (petit mal seizures), complex partial seizures (psychomotor or temporal lobe seizures), and simple partial seizures (focal seizures). 

TCA-induced seizures typically have no prodrome and are a single generalized motor seizure that lasts several minutes. The incidence of seizures during treatment with standard doses is estimated at 0.5% in nonepileptic patients ( 332). Patients who experience TCA-induced seizures during routine chemotherapy and with no other risk factors for seizures generally have plasma TCAs levels weli in excess of 450 ng/mL ( 331, 333). 

Seizures generally occur within days of a dose increase. 

Seizures generally occur within the first few hours after the dose. 

Drugs Used in Partial Seizures Generalized Tonic-Clonic Seizures... 

PARTIAL SEIZURES GENERALIZED TONIC-CLONIC SEIZURES... 

Phenobarbital Enhances phasic GABAa receptor responses reduces excitatory synaptic responses Nearly complete absorption not significantly bound to plasma proteins peak concentrations in Vi to 4 h no active metabolites tjy2 varies from 75 to 125 h Generalized tonic-clonic seizures, partial seizures, myoclonic seizures, generalized seizures, neonatal seizures, status epilepticus Toxicity Sedation, cognitive issues, ataxia, hyperactivity Interactions Valproate, carbamazepine, felbamate, phenytoin, cyclosporine, felodipine, lamotrigine, nifedipine, nimodipine, steroids, theophylline, verapamil, others... 

Gabapentin Decreases excitatory transmission by acting on VG Ca2+ channels presynaptically(a25 subunit) Bioavailability 50%, decreasing with increasing doses not bound to plasma proteins not metabolized ti/2 6—8 h Generalized tonic-clonic seizures, partial seizures, generalized seizures Toxicity Somnolence, dizziness, ataxia Interactions Minimal... 

Ephedra, Ma-huang Diet aid stimulant bronchodilator Central nervous system toxicity, cardiac toxicity Avoid in patients at risk for stroke, myocardial infarction, uncontrolled blood pressure, seizures, general anxiety disorder... 

D. Tonic seizures Generalized sustained muscle contractions throughout body loss of consciousness... 

Diphenylhydantoin is the most widely used drug in the treatment of all types of partial seizures, generalized tonic-clonic seizures and status epilepticus. It is relatively non-sedative. There is a good correlation between the increase in the blood levels of the drug and the occurrence of neurotoxicity, concentrations about 25 yg/ml usually being associated with such symptoms. 

Barbiturates are also used in infantile seizures that are not considered epilepsy. These seizures generally occur when an infant has a high fever, and therefore they are called febrile seizures. Phenobarbital is still commonly used to prevent seizures in infants, because scientists do not routinely study new drugs in infants and children. Because phenobarbital is... 

A patient exposed to water hemlock may convulse suddenly and without warning therefore, it is important to establish intravenous access immediately. For recent ingestions activated charcoal and a cathartic should be considered. Seizures generally respond to benzodiazepines. Care should be symptomatic and supportive. 

A good correlation usually is observed between the total concentration ofphenytoin in plasma and its clinical effect. Thus, control of seizures generally is obtained with concentrations >10 pg/mL, while toxic effects (e.g., nystagmus) develop at concentrations —20 pg/mL. 

Mechanism blockade of T-type channels and thalamic neurons 0 Use absence seizures General features of anticonvulsant drug use ... 

List the major drugs used for partial seizures, generalized tonic-clonic seizures, absence and myoclonic seizures, and status epilepticus. 

Tonic-clonic seizures, generalized Tonic phase (less than 1 minute) involves abrupt loss of consciousness, muscle rigidity and respiration arrest clonic phase (2-3 minutes) involves jerking of body muscles, with lip or tongue biting, and fecal and urinary incontinence formerly called grand mal... 

Absence seizures, generalized Impaired consciousness (often abrupt onset and brief), sometimes with automatisms, loss of postural tone, or enuresis begin in childhood (formerly, petit mal) and usually cease by age 20 years... 

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