No abstract available.
Phenytoin* ; Rhabdomyolysis*

No abstract available.
Phenytoin* ; Rhabdomyolysis*

This study was carried out on 36 blood samples of epileptic patients, between the ages of 6 and 15, in Army Hospital 103 during 9/2000 - 6/2001, who used a monotherapy - phenytoin. The results of quantitative analysis of serum concentration of drug in the treatment range, under the treatment range and above the treatment range among patients with disease free was 72.41%, 13.78% and 13.8%. 80% of patients used phenytorin at dose of 5-8mg/kg/day had a serum concentration in the treatment range. The dose of phenytoin can be increased increasingly in cases without responding to the treatment while the drug concentration closely reached the treatment range until the defects found.
Serum ; Phenytoin ; Epilepsy

It is important to predict time to reach therapeutic concentration in phenytoin toxicity. In tradition, frequent drug monitoring is inevitable until the therapeutic serum level is reached. A method of estimating Vmax and Vd of phenytoin with application to estimating time to reach therapeutic concentration of phenytoin is described. We evaluated the usefulness of that method in twelve patients with phenytoin toxicity whose initial levels ranging from 27.7 to 74.0 ug/ml. We compaired the observed time defined as the time of returning from the initial toxic level to the optimum therapeutic level by serial measurement of serum concentration with the calculated time by using the modified Michaelis-Menten equation (Km x In (C1/C2) +Cl-C2=Vmax/vd x T). We determined individual patient's Vmax (maximal metabolic rate of concentration), Vd(volume of distribution of concentration), and Km(constants of Michaelis-Menten equation) for phenytoin, using data obtained from two consecutive serum concentration and known value of Km in Korean. And then, we calculated the decline time of phenytoin. The calculated decline time did not differ significantly from observed decline time (P=0.830). It is possible to predict the time to the therapeutic range and to reduce the unnecessarily frequent drug monitoring.
Drug Monitoring ; Humans ; Phenytoin*

No abstract available.
Phenytoin* ; Stevens-Johnson Syndrome*

No abstract available.
Humans ; Hypersensitivity* ; Phenytoin*

The effect of diphenylhydantoin on LD 50 of ouabain was investigated in frogs, using "one hour frog method". LD50 of ouabain in control group was 1.90 microg/10g. A dose of 100 microg/10g diphenylhydantion did not affect the systemic manifestations of the frogs, but increase the LD50 of ouabain to 2.60 microg/10g. The difference of LD50 of ouabain and potency ratio between control group and diphenylhydantoin-treated group was statistically significant.
Lethal Dose 50 ; Ouabain* ; Phenytoin*

BACKGROUND: CEDIA is a newly developed method for therapeutic drug monitoring (TDM) and has some merits such as easy application to routine chemical analyzers, rapid and precise quantitation even in low concentrations and less cross reactivity. We evaluated the CEDIA(epsilon) (Microgenics Co., CA, USA) in measurement of theophyllin, valproic acid and phenytoin levels using 502X(epsilon) (A & T, Tokyo, Japan) and compared the results to those of the TDx(epsilon) (Abbott Laboratories, IL, USA) in order to assess the utility of the CEDIA(epsilon). METHODS: We evaluated the performance of 502X(epsilon) in the aspects of the within-runs and the between-runs precision, linearity, and carry-over. We compared the results of the CEDIA(epsilon) reagent with those of TDx(epsilon). The control materials (Bio-Rad TDM control level 1 and level 3; Bio-Rad laboratories, CA, USA) and clinical specimens were used for these studies. RESULTS: The coefficients of variation (CV) for the within-run and the between-run imprecision of 502X(epsilon) were 2.0-7.6% and 4.0-6.5%, respectively. The carry-over rate for theophyllin, valproic acid and phenytoin was 1.33%, 0.45% and 0.53%, respectively. The linearity (r(2)) of theophyllin, valproic acid and phenytoin was 0.9941, 0.9983 and 0.9947, respectively. The correlation coefficients (r) of theophyllin, valproic acid and phenytoin levels of CEDIA(epsilon), with those determined by the TDx(epsilon), were 0.9730, 0.9703 and 0.9695, respectively (P<0.001). CONCLUSIONS: The recentlydeveloped CEDIA(epsilon) proved to be highly precise and linear for quantitative analysis of theophyllin, phenytoin and valproic acid. Correlations with TDx(epsilon) were significantly high. CEDIA(epsilon) was thought to be clinically useful for TDM.
Drug Monitoring ; Phenytoin* ; Theophylline* ; Valproic Acid*

Diphenylbydantoin-induced movement disorders have been rarely reported. They include choreoathetosis, orofacial dyskinesia, asterixis, dystonia, and ballismus. A patient with epllepsy, who showed orofacial dyskinesia with toxic cerebellar syrnptoms after longterm use of diphenylhydantoin is presented. The involuntary movement rapidily disappeared with a reduction of diphenylhydantoin dose.
Dyskinesias ; Dystonia ; Humans ; Movement Disorders* ; Phenytoin

A possible drug interaction between phenytoin and dexamethasone was evaluated by comparing serum phenytoin concentrations in 34 patients receiving both drugs with those if a control group 19 patients receiving phenytoin only. Serum phenytoin concentrations obtained 24 hours after a loading dose of 15mg per kilogram body weight administrated intravenously were examined. The serum concentrations of phenytoin were checked by homogenous enzyme immunoassay(EMIT) method. The total amounts of dexamethasone administered during the 24 hours period ranged from 10 to 40mg. The average serum phenytoin concentration was 12.08+/-2.78 microgram/ml in patients receiving both drugs, as compared to 8.58+/-2.72 microgram/ml in patients receiving phenytoin only(p<0.005). Our results suggest that serum phenytoin concentrations in patients receiving both drugs were higher than in patients receiving phenytoin only.
Body Weight ; Dexamethasone ; Drug Interactions ; Humans ; Phenytoin