Clinical detection and assessment of drug induced neurotoxicity

• 1.

  1. Drug-induced neurological disease is a relatively common problem. For example, the Boston Collaborative Drug Surveillance Program reported that in 11,526 hospitalized patients, 14.2% of adverse drug reactions (ADRs) were neurological.

• 2.

  2. Drugs can induce various syndromes such as: disturbances of consciousness, psychiatric disorders, headache, cranial nerve disorders, movement disorders, psychosis, peripheral neuropathy, myopathy and autonomic dysfunction.

• 3.

  3. The vast majority of ADRs are dose-related (e.g. CNS depression by sedative-hypnotics). In these cases the frequency and severity of the ADRs is proportional to the administered dose, therefore, they can be prevented and/or treated by adjusting the dosage to patient's needs. Dose-unrelated ADRs (e.g. malignant hyperthermia by various anaesthetic agents) are uncommon and the development of the reaction is mainly dependent on increased patient's susceptibility. Accordingly, the ADR can only be prevented by not readministering the drug.

• 4.

  4. Most of the evidence associating specific drugs with neurological adverse events comes from single case reports in which no systematic assessment of causality has been made. Recently, valid and reliable definitions of ADRs have been reported (e.g. Kramer et al, 1979; Naranjo et al, 1981). The systematic application of these methods greatly reduce the ambiguity for analyzing alleged cases of ADRs. These methods can be easily applied by practising physicians in the assessment and reporting of suspected drug-induced neurological diseases.