Yes, discontinue Abilify immediately in this patient with severe hyponatremia (sodium 125 mmol/L).
Aripiprazole should be stopped now given the documented association between this medication and syndrome of inappropriate antidiuretic hormone (SIADH), particularly when a patient presents with significant hyponatremia. The sodium level of 125 mmol/L represents moderate-to-severe hyponatremia that requires urgent intervention.
Evidence Supporting Discontinuation
The FDA label for Abilify does not specifically contraindicate use in hyponatremia, but multiple case reports demonstrate a clear causal relationship 1. Most compelling is a case where a 65-year-old patient developed severe hyponatremia (sodium 108 mmol/L) after aripiprazole dose increase, improved with discontinuation, then redeveloped hyponatremia upon inadvertent rechallenge - achieving a Naranjo probability score of 7 (probable causality) 2. A 2025 case report further confirms this rechallenge phenomenon 3.
A systematic review found that antipsychotic-induced hyponatremia may be "much higher than currently thought," with both typical and atypical antipsychotics implicated. The review noted that 80% of cases showed possible causality and 19% showed probable causality using standardized assessment 4.
Clinical Assessment Required
Before stopping the medication, quickly determine:
- Symptom severity: Is the patient experiencing confusion, nausea/vomiting, weakness, or seizures? These indicate need for ICU-level care 5
- Chronicity: Acute (<48 hours) versus chronic hyponatremia - this determines correction rate
- Volume status: Check for signs of hypovolemia, euvolemia, or hypervolemia to guide fluid management
- Urine studies: Obtain urine sodium and osmolality to confirm SIADH (urine osmolality >100 mOsm/kg with inappropriately concentrated urine)
Management Algorithm
Discontinue aripiprazole immediately - do not wait for confirmatory testing
Assess symptom severity:
- Severe symptoms (altered mental status, seizures): Transfer to ICU, correct 6 mmol/L over 6 hours with 3% hypertonic saline, then limit total correction to 8 mmol/L in 24 hours 5
- Mild symptoms (nausea, headache, weakness): Fluid restriction to 1L/day, monitor sodium every 4 hours 5
- Asymptomatic: Fluid restriction, daily sodium monitoring
Avoid rapid overcorrection in chronic hyponatremia (>48 hours duration) - limit to <8 mmol/L per 24 hours to prevent osmotic demyelination syndrome 5, 6
Monitor response: Sodium should improve within 24-72 hours after stopping aripiprazole if drug-induced 2
Critical Pitfall
Do not restart aripiprazole even if the patient's psychiatric condition worsens. The rechallenge case demonstrates that reintroduction will likely cause recurrent severe hyponatremia 2, 3. Work with psychiatry to identify an alternative antipsychotic without SIADH risk.
Alternative Antipsychotic Selection
Choose an agent with lower SIADH risk while considering the patient's psychiatric indication. Document aripiprazole as a medication allergy/adverse reaction to prevent future inadvertent rechallenge.