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Thiazide Diuretic Pregnancy: Avoid — neonatal thrombocytopenia, jaundice; not first-line in pregnancy hypertension

Bendroflumethiazide

Brand names: Bendroflumethiazide (generic), Centyl (less common)

Adult dose

Dose: Hypertension: 2.5 mg OD (morning). Oedema: 5–10 mg OD in the morning.
Route: Oral
Frequency: Once daily in the morning
Max: 10 mg/day (oedema); 5 mg/day (hypertension — rarely need more than 2.5 mg)
Low-dose (2.5 mg) is sufficient for antihypertensive effect with fewer metabolic side effects. Higher doses primarily diuretic. Does not work effectively if eGFR <30.

Paediatric dose

Dose: 0.05 mg/kg
Route: Oral
Frequency: OD–BD
Max: 5 mg/day
Rarely used in children; specialist use only

Dose adjustments

Renal

Avoid if eGFR <30 — ineffective as diuretic; only use if alternative not available

Hepatic

Caution — electrolyte disturbances may precipitate hepatic encephalopathy

Paediatric weight-based calculator

Rarely used in children; specialist use only

Clinical pearls

  • NICE NG136: thiazides appropriate as add-on antihypertensive when CCB not tolerated or in patients with oedema
  • Dose 2.5 mg: equivalent antihypertensive effect to 5 mg or 10 mg, but fewer metabolic side effects
  • May not work in CKD (eGFR <30) — loop diuretic more effective for oedema in CKD
  • Associated with reduced risk of hip fracture (calcium retention effect) — useful in osteoporosis risk patients

Contraindications

  • Addison's disease
  • Symptomatic hypercalcaemia
  • Refractory hypokalaemia or hyponatraemia
  • Sulfonamide hypersensitivity

Side effects

  • Hypokalaemia (important at higher doses)
  • Hyponatraemia
  • Hyperglycaemia
  • Hyperuricaemia (gout)
  • Hypercalcaemia
  • Impotence
  • Hyperlipidaemia (modest, minimal at 2.5 mg)

Interactions

  • NSAIDs — reduce diuretic effect
  • Lithium — reduced lithium clearance (increased toxicity)
  • Digoxin — hypokalaemia increases toxicity
  • ACEi — first-dose hypotension risk (but beneficial combination long-term)

Monitoring

  • Electrolytes (K+, Na+, Ca2+) after starting and with dose changes
  • Blood glucose
  • Uric acid (if gout history)
  • Blood pressure

Reference: BNFc; BNF; NICE NG136. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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