Clinical presentation

Effects of chronic lithium toxicity include:

• CNS effects—tremor, hyperreflexia, ataxia, rigidity, drowsiness, confusion, coma, seizures, myoclonus
• cardiovascular effects
  • QT-interval prolongation is uncommon, but can occur in severe poisoning; arrhythmias are rare
  • bradycardia, hypotension
• gastrointestinal effects—nausea, vomiting.

Lithium-associated nephrogenic diabetes insipidus causes dehydration and hypernatraemia. It is common in those taking long-term lithium therapy and potentiates chronic lithium toxicity.