Severe toxicity is treated symptomatically; there are no antidotes. Convulsions are usually managed with intravenous diazepam or a short-acting barbiturate such as thiopental. Hyperventilation with oxygen is helpful. Occasionally, a neuromuscular blocking drug may be used to control violent convulsive activity. The cardiovascular toxicity of bupivacaine overdose is difficult to treat and has caused fatalities in young adults; intravenous administration of lipid has been reported to be of benefit.