Hepatic cirrhosis secondary to excess alcohol consumption is increasing in incidence, and these patients can develop ataxia secondary to direct toxic effects of alcohol on the cerebellum. However, it is important to remain vigilant for other causes of an unsteady gait, including space-occupying lesions and medications, such as phenytoin. Patients with hypoalbuminaemia, such as those with cirrhosis, are more prone to developing toxic effects from phenytoin, as this Lesson describes. Therefore, dose adjustments might be necessary.