Nausea, diarrhoea, vomiting, dyspepsia, abdominal pain, flatulence, anorexia, dizziness, headache, tiredness, agitation, trembling. Insomnia, peripheral paralgesia, sweating, unsteady gait, convulsions, increase in intracranial pressure, anxiety states, nightmares, confusion, depression, hallucinations, impaired taste & smell, visual disturbances, tinnitus, transitory impairment of hearing, especially at high frequencies, skin reactions.