Advice for prescribers- patient’s taking antidepressants with hyponatraemia
Hyponatraemia (usually in the elderly and possibly due to inappropriate secretion of antidiuretic hormone) has been associated with all types of antidepressants; however, it has been reported more frequently with SSRIs than with other antidepressants. Hyponatraemia should be considered in all patients who develop drowsiness, confusion, or convulsions while taking an antidepressant.
Hyponatraemia is associated with emergency admissions, especially in the frail elderly.
SFT have been receiving increasing numbers of referrals from primary care asking them to review patients who are taking antidepressants and have a finding of hyponatraemia. SFT advise:
- In mild hyponatraemia (>125mml/L -133mmol/L) monitor sodium and symptoms in the first instance, rather than switching patients away from a medicine that is effective for them. Consider appropriateness of continuing the antidepressant and/ or other medications being taken which may increase the risk of hyponatraemia (e.g. diuretics, NSAIDs, antipsychotics, carbamazepine, cancer chemotherapy, calcium antagonists, ACE inhibitors and laxatives).
- If serum sodium <125mmol/L discontinue the antidepressant immediately and seek specialist medical care.
- Discuss the risks (of hyponatraemia if continuing the antidepressant vs risks of depression coming back if stopping the antidepressant) with patient and record the decision in the patient notes
- Please continue to ask for advice where patients have severe or worsening hyponatraemia or where symptoms of hyponatraemia persist, preferably by phone or email with your local mental health team rather than making a referral.
Mendip CMHT
Wells Tel: 01749 836600
Taunton & Minehead CMHT
Taunton Tel: 01823 368350
Minehead Tel: 01643 701701
Somerset Coast CMHT
Bridgwater Tel: 01278 720220
South Somerset CMHT
Yeovil Tel: 01935 428420
Sedgemoor:
Telephone: 0300 1245601 (option 1)
Email: OPMHSedgemoor@somersetft.nhs.uk
The Maudsley Prescribing Guidelines in Psychiatry 14th Edition. Accessible via NHS library knowledge hub.
