Moderate
Furosemide × Sertraline
Loop diuretics×Selective serotonin reuptake inhibitors (SSRIs)
Mechanism
Both can cause hyponatraemia: furosemide via natriuresis, sertraline via SIADH-like mechanism. Additive risk, especially in older women with low body weight.
Symptoms
Headache, nausea, confusion, drowsiness; severe cases: seizures. Develops slowly over 1–2 weeks and is often missed in older patients.
Management
Check sodium 2 weeks after sertraline start, then every 6 months. If sodium falls below 130 mmol/L, switch sertraline to mirtazapine or agomelatine (do not cause hyponatraemia). In older patients with moderate hyponatraemia, fluid restriction to 1.5 L/day.
Sources
- Lexicomp: Lexicomp Drug Interactions (2024)– Wolters Kluwer Clinical Drug Information, Inc. Lexi-Interact Online, 2024
- AGS: American Geriatrics Society Beers Criteria for Potentially Inappropriate Medication Use (2023)– By the 2023 American Geriatrics Society Beers Criteria Update Expert Panel. AGS Beers Criteria for Potentially Inappropriate Medication Use in Older Adults. J Am Geriatr Soc 2023;71(7):2052-2081.