Summary
The relationship between oral dose and plasma concentration of ethosuximide was evaluated retrospectively in 198 epileptic patients aged 2.5 to 34 years. Age appears to be a major factor in determining the ethosuximide plasma level/dose (L/D) ratio. Children younger than 10 years had mean L/D ratios significantly lower (p<0.0003) than adolescents (10 to 15 years of age) and adults (16 to 34 years of age). Associated antiepileptic therapy reduced the ethosuximide L/D ratio; mean ethosuximide L/D ratios were significantly lower in patients also taking primidone (p < 0.0005) or valproic acid (p < 0.02). The correlation between the dose of ethosuximide administered and the plasma concentration was significant in the 3 age groups considered (p < 0.0004), but the wide scattering of individual plasma concentrations makes it impossible to predict what plasma concentration of ethosuximide will be obtained after a given dose. For this reason, routine monitoring of ethosuximide plasma concentrations still appears to be necessary, especially in children and patients on polytherapy.
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References
Browne, T.R.; Dreifuss, F.E; Dyken, P.R.; Goode, D.J.; Penry, J.K.; Porter, R.J. and White, B.G.: Ethosuximide in the treatment of absence (petit mal) seizures. Neurology (Minneapolis) 25: 515–524 (1975).
Buchanan, R.A.; Fernandez, L. and Kinkel, A.W.: Absorption and elimination of ethosuximide in children. Journal of Clinical Pharmacology 9: 393–398 (1969).
Buchanan, R.A.; Kinkel, A.W. and Smith, T.C.: The absorption and excretion of ethosuximide. International Journal of Clinical Pharmacology 1: 213–218 (1973).
Chang, T.; Dill, W.A. and Glazko, A.J.: Ethosuximide absorption, distribution and excretion; in Woodbury et al. (Eds) Anti-epileptic Drugs, pp.417–423 (Raven Press, New York 1972).
Goulet, J.R.; Kinkel, A.W. and Smith, T.C.: Metabolism of ethosuximide. Clinical Pharmacology and Therapeutics 20: 213–218 (1976).
Haerer, A.F.; Buchanan, R.A. and Wiygul, F.M.: Ethosuximide blood levels in epileptics. Journal of Clinical Pharmacology 10: 370–374 (1970).
Morselli, P.L.: Antiepileptic drugs; in Morselli (Ed) Drug Disposition During Development, pp.311–360 (Spectrum, New York 1977).
Penry, J.K.; Porter, R.J. and Dreifuss, F.E.: Ethosuximide relation of plasma levels to clinical control; in Woodbury et al. (Eds) Antiepileptic Drugs, pp.431–441 (Raven Press, New York 1972).
Sherwin, A.L.: Clinical pharmacology of ethosuximide; in Pip-pinger et al. (Eds) Antiepileptic Drugs: Quantitative Analysis and Interpretation, pp.283–295 (Raven Press, New York 1978).
Sherwin, A.L and Robb, J.P.: Ethosuximide relation of plasma levels to clinical control; in Woodbury et al. (Eds) Antiepileptic Drugs, pp.443–448 (Raven Press, New York 1972).
Smith, G.A.; McKauge, L.; Dubetz, D.; Tyrer, J.H. and Eadie, M.J.: Factors influencing plasma concentrations of ethosuximide. Clinical Pharmacokinetics 4: 38–52 (1979).
Solow, E.B. and Green, J.B.: The determination of ethosuximide in serum by gas chromatography. Preliminary results of clinical application. Clinica Chimica Acta 33: 87–90 (1971).
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Battino, D., Cusi, C., Franceschetti, S. et al. Ethosuximide Plasma Concentrations: Influence of Age and Associated Concomitant Therapy. Clin Pharmacokinet 7, 176–180 (1982). https://doi.org/10.2165/00003088-198207020-00006
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DOI: https://doi.org/10.2165/00003088-198207020-00006