Makindo Medical Notes.com

Toxic levels >2 mmol/L. Hydration and haemodialysis for toxicity.

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• Lithium has a low therapeutic index
• It becomes toxic at a level not far from its therapeutic level

Mode of action

• Possibly changes the intracellular environment
• Action on secondary messengers, enzymes, biosynthetic pathways
• Newest ideas based upon effects on adenylate cyclase and subsequently G-protein mediators of transduction systems and effects on phosphoinositol turnover,

Indication/Dose

• Lithium is a chemical element of atomic number 3 and is a soft alkali metal
• The Lithium-Ion has mood stabilising effects
• Mania and hypomania, Bipolar disorder, Acute mania, cluster headaches

Contraindications

• See Interactions. Watch levels in those with impaired renal function, elderly, on diuretics
• Toxicity with ACEI and Dihydropyridine calcium channel blockers

Dose

• Lithium 400 mg to 1.2 g daily as a single dose or in divided doses.
• U&E, creatinine, and TFTs should be checked before starting any patient on Lithium

Monitoring

• Sample at 4-7 days at 12 h post dose
• Level should be 0.4-1.0 mmol/L and aim for 0.6-0.8 mmol/L

Side effects

• Nausea and vomiting, Drowsiness and confusion
• Seizures, Tremor, ataxia, nystagmus and dysarthria
• Gastrointestinal distress, particularly diarrhoea, Oedema and weight gain
• Reversible nephrogenic diabetes insipidus (blocks Vasopressin-induced adenylate cyclase)
• Chemical hypothyroidism

Interactions: Lithium toxicity may be caused or exacerbated by

• Thiazides, NSAIDS, ACEI,Furosemide (mild)
• Dehydration, Advanced age, Renal disease
• Verapamil in combination with lithium leads to neurotoxicity

References

• Summary Product Characteristics