Anticonvulsant hypersensitivity syndrome (AHS) is an uncommon, but potentially fatal, multisystem disorder that occurs after exposure to phenytoin, carbamazepine, or phenobarbital. Its incidence is estimated to range from 1 per 1000 to 1 per 10,000 exposures.<sup>3 Bertz R.J., Howrie D.L. Diazepam by continuous intravenous infusion for status epilepticus in anticonvulsant hypersensitivity syndrome Ann Pharmacother 1993 ;  27 : 298

Cliccare qui per andare alla sezione Riferimenti, 8 Chang D.K.M., Shear N.H. Cutaneous reactions to anticonvulsants Semin Neurol 1992 ;  12 : 329

Cliccare qui per andare alla sezione Riferimenti, 11 Gaedigk A., Spielberg S.P., Grant D.M. Characterization of the microsomal epoxide hydrolase gene in patients with anticonvulsant adverse drug reactions Pharmacogenetics 1994 ;  4 : 142  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti, 13 Gennis M.A., Vermuri R., Burns E.A. , e al. Familial occurrence of hypersensitivity to phenytoin Am J Med 1991 ;  91 : 631  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti, 29 Leeder J.S., Riley R.J., Cook V.A. , e al. Human anti-cytochrome P450 antibodies in aromatic anticonvulsant-induced hypersensitivity reactions J Pharmacol Exp Ther 1992 ;  263 : 360

Cliccare qui per andare alla sezione Riferimenti, 57 Vittorio C.C., Muglia J.J. Anticonvulsant hypersensitivity syndrome Arch Intern Med 1995 ;  155 : 2285

Cliccare qui per andare alla sezione Riferimenti</sup> With diverse clinical features and variable presentations, there often is a delay in making the correct diagnosis. Furthermore, cross-reactivity between these three anticonvulsants may exceed 50%, explaining why patients may worsen when one anticonvulsant is stopped and one of the others begun. Physicians must be familiar with the spectrum of AHS to recognize the syndrome early, and must understand the implications for reactions to other anticonvulsants when a hypersensitivity reaction is recognized. This article describes the time course and general features of the syndrome and briefly reviews the history of hypersensitivity reactions for each drug. The pathophysiology that is thought to explain both the occurrence of AHS and cross-reactivity between the three drugs along with new diagnostic tests and suggestions for therapy are also reviewed. The potential for felbamate as a cause of AHS is also discussed.