Lithium

• Bipolar affective disorder maintenance (non-pregnant)
• Prevention of postpartum bipolar relapse (specialist)

Not fully understood — modulates IP3/DAG second messengers, GSK-3β inhibition, neuroprotection.

• Ebstein's anomaly RR ~1.5–3 (absolute ~1 in 1000)
• Levels rise sharply after delivery — check weekly late T3
• Neonatal 'floppy baby', hypothyroidism, DI

Standard

400–1200 mg OD (target level 0.6–1.0 mmol/L)

Pregnancy monitoring

Levels every 4 weeks, then weekly from 36 weeks, then postpartum

• AbsoluteSevere renal impairment
• AbsoluteUntreated hypothyroidism
• CautionPregnancy — specialist perinatal psychiatry only

• Tremor, polyuria (nephrogenic DI)
• Hypothyroidism, hyperparathyroidism
• Weight gain
• Toxicity: coarse tremor, ataxia, seizures, coma

• • T1: Ebstein's anomaly and other cardiac defects — fetal echo at 18–20 wk
• • T3: monitor neonate for hypotonia, poor feeding, thyroid + renal function
• • Breastfeeding possible with close monitoring

• NSAIDs

  Avoid

  ↑ lithium levels significantly

• ACEi / ARB / diuretics

  Avoid

  ↑ lithium levels

• Antipsychotics

  Caution

  Neurotoxicity (esp. haloperidol)

• 💡 Hydration and sodium status crucial — avoid dehydration in HG or labour
• 💡 Halve dose or hold at labour onset per perinatal psychiatry plan