3. Individuals taking the following medications that may affect the autonomic nervous system: anti- tuberculosis drugs, nitrofurantoin, metronidazole, chloramphenicol,perhexiline maleate, amiodarone, clofibrate, tricyclic antidepressants, phenytoin,methotrexate, barbiturates, neuroleptic drugs, antiparkinsonism drugs, fluoxetine, and nitrated drugs.