ABSTRACT
The interferons (IFNs), first described in 1957, are a group of at least five natural human glycoproteins (alpha, beta, gamma, omega and, tau) with marked antiviral, antiproliferative, and immunomodulatory activity. Only the first three types are currently used clinically. Various forms of IFN-a have been approved worldwide in the treatment of a variety of diseases, including solid and hematological malignancies and viral disorders, such as hepatitis B virus- or hepatitis C virus-related chronic hepatitis. Interferon-a is the only approved drug for the treatment of chronic viral hepatitis. A wide range of neuropsychological disturbances have been described in IFN-a-treated patients. Symptoms such as cephalalgia, malaise, somnolence, or mnesic disorders are typically associated with the flu-like syndrome or occur shortly thereafter. Weight loss with a mean decrease of 2 to 5 kg is also common. Various severe neurological symptoms have been reported. A 1.3% incidence of generalized tonic-clonic seizures was found in a retrospective study of 311 patients.
