Thiazide-like diuretic

Chlortalidone

Brand names: Hygroton

Chlortalidone is a long-acting thiazide-like diuretic used for hypertension, with strong outcome evidence as an antihypertensive.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

It inhibits sodium-chloride reabsorption in the distal convoluted tubule, producing a sustained diuresis and lowering blood pressure partly through reduced vascular resistance.

Prescribing in practice

Monitor U&E for hypokalaemia and hyponatraemia, which can be clinically significant and develop gradually.
Metabolic effects include hyperglycaemia, hyperuricaemia with gout, and hypercalcaemia.
Use caution in significant renal or hepatic impairment, and review electrolytes more closely in the elderly.

Monitoring

Monitor renal function and electrolytes (especially potassium and sodium) before starting and periodically, and consider checking glucose and urate where relevant.

Counselling the patient

Take it in the morning to reduce night-time urination.
Report muscle cramps, marked weakness or confusion, which may indicate a salt imbalance, and mention any history of gout.

Evidence & guidelines

Guideline-recognised thiazide-like diuretic with robust antihypertensive outcome data (NICE NG136).

Reference: NICE NG136; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Drugs

Pathways