Lithium

• Examples:

  • Lithium carbonate - Camcolit, Priadel, Liskonum
  • Lithium citrate - Li-liquid, Priadel
  • Contains different concentrations of lithium so important to keep the patient on the same formulation
  • Must be prescribed by brand
• MOA:

  • Exact mechanism unknown
  • Modifies the production and turnover of certain neurotransmitters, particularly serotonin and may also block dopamine receptors
  • Alters concentrations of certain electrolytes and may reduce thyroid activity
• Indications:

  • Bipolar affective disorder
  • Acute episodes of mania and hypomania
  • Recurrent depression where treatment with other antidepressants has failed
  • Control of aggressive behaviour or intentional self-harm
• Contraindications:

  • Cardiac disease
  • Personal or family history of Brugada syndrome
  • Untreated hypothyroidism - lithium can cause or exacerbate hypothyroidism
• Caution:

  • Pregnancy - risk of Epstein's anomaly (cardiac malformation)
  • Renal impairment - avoid in severe impairment (lithium mostly renally excreted)
  • Low body sodium levels e.g. dehydration, low sodium diet - increased risk of lithium toxicity
• Interactions:

  • Increased lithium concentration:

  1. Diuretics - sodium depletion increases toxicity
  2. ACEi, ARBs and NSAIDs - reduce lithium clearance as affect renal function

  • Reduced lithium concentration - sodium chloride supplements
  • QT prolongation - amiodarone, venlafaxine
  • Increased risk of torsade de points - aminophylline, clarithromycin
  • Increased risk of serotonin syndrome - SSRIs, MAOIs
• Narrow therapeutic window and high toxicity risk:

  • Monitor plasma lithium levels, should be 0.4-1 mmol/L
  • When starting lithium - weight, FBC, U+Es, TFTs, eGFR and ECG
  • Check serum lithium levels 1 weeks after initiation and after every dose adjustment
  • Blood lithium levels should be checked 12 hours after last dose
• Ongoing monitoring:

  • Check renal function and TFTs every 6 months
  • Annual measurement of blood pressure, weight and BMI
• Common side effects:

  • Fine tremor
  • Thirst and polyuria - nephrogenic diabetes insipidus
  • Weight gain
  • Taste disturbance - metallic taste
  • Hypothyroidism
  • Goitre
• Rare side effects:

  • Lithium toxicity
  • Leucocytosis - raised WCC
• Lithium toxicity:

  • Anorexia
  • Nausea and vomiting
  • Nystagmus
  • Coarse tremor
  • Dysarthria
  • Ataxia
  • Severe cases - LOC, seizures and death
• Why and how to take:

  • Lithium works as a mood stabiliser and is advisable that lithium therapy is not started unless there is an intention to continue for 3 years - poor compliance may precipitate rebound mania
  • Patient should take dose at same time each day
  • If miss dose - do not double dose, take next dose as prescribed
• Counselling:

  • Take same time each day, do not double dose
  • Stay hydrated and do not make dietary changes - avoid depletion of sodium
  • Do not stop taking lithium without discussion with doctor - risk of relapse
  • Blood tests - regular blood tests at start of treatment, once stable every 3 months
  • Sings of toxicity
  • Treatment card
  • Withdrawal
  • Contraception
• Lithium treatment card:

  • Advise patient to carry their lithium treatment card and alert card
  • Show all healthcare professionals this card prior to treatment, including dentists and any over the counter medicines
• Same brand:

  • It is important that the patient is maintained on the same formulation of lithium during treatment, once they are stable
  • Advise patient to check the brand of the lithium they are prescribed
• Withdrawal:

  • If lithium should be withdrawn, it should be done gradually and under medical supervision
• Contraception:

  • Lithium is a teratogenic drug and so should be avoided in pregnant women
  • Should only be considered in pregnant women if the therapeutic benefit outweighs the risk of harm to the unborn child
  • Sexually active females of child-bearing age are advised to use contraception