Phenytoin convulsive status epilepticus

FIGURE 56-1. Algorithm for the management of generalized convulsive status epilepticus. (CBC, complete blood cell count EEG, electroencephalogram HR, heart rate PE, phenytoin sodium equivalents PR, per rectum RR, respiratory rate.)... 

The therapeutic plasma level of phenytoin for most patients is between 10 and 20 g/mL. A loading dose can be given either orally or intravenously the latter, using fosphenytoin, is the method of choice for convulsive status epilepticus (discussed later). When oral therapy is started, it is common... 

In a multicenter, randomized, double-blind comparison of diazepam (0.15 mg/kg followed by phenytoin 18 mg/kg), lorazepam (0.1 mg/kg), phenobarbital (15 mg/kg), and phenytoin (18 mg/kg) in 518 patients with generalized convulsive status epilepticus, lorazepam was more effective than phenytoin and at least as effective as phenobarbital or diazepam plus phenytoin (1). Drug-related adverse effects did not differ significantly among the treatments and included hypoventilation (up to 17%), hypotension (up to 59%), and cardiac rhythm disturbances (up to 9%). 

TreimanDM, De Giorgio CM, Ben-Menachem E, etal. Lorazepam versus phenytoin in the treatment of generalized convulsive status epilepticus Report of an ongoing study. Neurology 1985 35 284. 

Phenytoin is indicated for initial monotherapy or adjunct treatment of complex partial or tonic-clonic seizures, convulsive status epilepticus, and prophylaxis. It often is selected for initial monotherapy because of its high efficacy and relatively low incidence of side effects (29). Phenytoin is not used in the treatment of absence seizures, because it may increase their frequency of occurrence (30,31). Phenytoin binds to and stabilizes the inactivated state of sodium channels, thus producing a use-dependent blockade of repetitive firing and inhibition of the spread of seizure activity to adjacent cortical areas. 

Skin A woman developed localized skin necrosis after intravenous administration of phenytoin for generalized convulsive status epilepticus. The authors consequently made some recommendations for the intravenous administration of phenytoin a dedicated intravenous caimula should be inserted in a large peripheral vein the rate of administration should not exceed 50 mg/minute the cannula should be periodically flushed with saline after each bolus continuous monitoring for signs of extravasation, hypotension, and bradycardia should be performed [253 ]. 

VPA versus phenytoin In a systemic review evaluating the efficacy and tolerability of intravenous VPA and intravenous phenytoin for convulsive status epilepticus, VPA had a significantly lower rate of adverse events compared to phenytoin (9.7% vs 34.8%). There was no statistically significant difference in seizure freedom at 24 h [32 ]. 

Seizures are present in 30% of patients with star fruit intoxication [17], and most patients have convulsive [6, 8,10,11,13,14,17,18,19] or non-convulsive [16] status epilepticus. The mortality rate of patients with seizures occurring after star fruit intoxication (severe intoxication) is significantly higher than of patients without seizures [13, 17]. Phenytoin, midazolam, diazepam and phenobarbital seem to have little or no effect on the control of persistent seizures provoked by star fruit toxicity. However, significant clinical improvement of seizure was demonstrated in one patient after the use of profofol [20]. 

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