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Treatment of patients with chronic heart failure with resistant volume overload.

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Nice TA:

Commissioning responsibility:


PbR excluded:


BNF chapter:
Blood and Nutrition


Before requesting primary care prescribing, patients must be established on a stable dose of metolazone for at least 2 weeks, with stable urea and electrolytes (including creatinine) and a stable body weight before discharge.

Ongoing monitoring of urea and electrolytes (including creatinine) should be carried out on a monthly basis and the patients’ weight and blood pressure should be monitored at each clinic visit.

Metolazone has an established role in the treatment of resistant oedema in heart failure where it is combined with a loop diuretic. The combination of metolazone and a loop diuretic is much more potent and needs to be initiated by someone experienced in its use and needs careful monitoring of renal function and electrolytes. It is routinely used in patients with renal impairment who do not respond to a loop diuretic.

Metolazone is only available as an unlicensed special order, imported, product from Canada, where it does hold a licence (Zaroxolyn 2.5mg and 5mg tablets).  The drug has a full monograph in the BNF with the Zaroxolyn brand listed in the medicinal forms section.

Canadian product information for Zaroxolyn  

BNF monograph for Metolazone  

BNF Metolazone medicinal forms section


LSCMMG Recommendation:

Amber level 0

Reason for decision:

Suitable for GP prescribing following recommendation/initiation by specialist

Supporting documents:

Decisions of Lancashire local decision making groups

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Last Updated: 16 - Nov - 2020