K-sparing diuretic (ENaC blocker)
Triamterene
Brand names: Dytac
Adult dose
Dose: 150–250mg PO/day in divided doses
Route: PO
Frequency: OD-BD
Dose adjustments
Renal
Avoid if eGFR <30
Clinical pearls
- Adjunct to thiazides/loop in oedema; rarely used alone
- Take with food
Contraindications
- Hyperkalaemia
- Severe renal impairment
- Concurrent K-sparing diuretic / K supplements
- Anuria
- Severe hepatic impairment
Side effects
- Hyperkalaemia
- GI upset
- Megaloblastic anaemia (folate antagonism)
- Renal stones (rare)
- Blue urine fluorescence
Interactions
- ACEi/ARB
- Lithium
- NSAIDs
- K supplements
Monitoring
- U&E
- K+
Reference: BNF; NICE; https://bnf.nice.org.uk/drugs/triamterene/. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.
Calculators
Pathways
- Acute Heart Failure · ESC 2021 Heart Failure Guidelines; NICE NG106
- NSTEMI / Unstable Angina · ESC 2020 NSTEMI Guidelines; NICE NG185
- New-Onset Atrial Fibrillation · ESC 2020 AF Guidelines; NICE NG196
- Hypertensive Emergency · ESC/ESH 2018 Hypertension Guidelines; NICE NG136
- Bradycardia Management · Resuscitation Council UK ABCDE; ESC 2021 Pacing Guidelines
- Ventricular Tachycardia / Fibrillation · Resuscitation Council UK ACLS; ESC 2022 Ventricular Arrhythmia Guidelines