McKenna's Pharmacology for Nursing, 2e

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P A R T 9  Drugs acting on the renal system

TABLE 51.1

DRUGS IN FOCUS Diuretics (continued)

Drug name

Dosage/route

Usual indications

Potassium-sparing diuretics amiloride (Kaluril)

5–10 mg/day PO to maximum 20 mg/day

Adjunctive treatment of oedema caused by HF, liver disease or renal disease; hypertension; hyperkalaemia; and hyperaldosteronism Special consideration: Not for use in children Risk reduction in people with heart failure and left ventricular impairment following AMI Adjunctive treatment of oedema caused by HF, liver disease or renal disease; hypertension; hyperkalaemia; and hyperaldosteronism Special consideration: Can be used in children with careful monitoring of electrolytes Adjunctive treatment of oedema caused by HF, liver disease or renal disease; hypertension; hyperkalaemia; and hyperaldosteronism Special consideration: Not for use in children Treatment of oedematous states, including cerebral oedema Treatment of elevated intracranial pressure, acute renal failure, acute glaucoma; also used to decrease intracranial pressure, prevent oliguric phase of renal failure,

eplerenone (Inspra)

25 mg/day PO titrated to 50 mg/day PO within 4 weeks

100–200 mg/day PO for oedema; 100–400 mg/day PO for hyperaldosteronism; 50–100 mg/day PO for hypertension Paediatric: 3.3 mg/kg per day PO

spironolactone (Aldactone)

triamterene (Hydrene)

100 mg PO mané or b.d

Osmotic diuretics glucose (generic)

IV; depends on individual

50–100 g IV for oliguria; 1.5–2 g/kg IV to reduce intracranial pressure; dose not established for children <12 years

mannitol (Osmitrol)

and to promote movement of toxic substances through the kidneys

Drug therapy across the lifespan

BOX 51.1

Diuretic agents CHILDREN

Because of the size and rapid metabolism of children, the effects of diuretics may be rapid and adverse effects may occur suddenly.The child receiving a diuretic should be monitored for serum electrolyte changes; for evidence of fluid volume changes; for rapid weight gain or loss, which could reflect fluid volume; and for signs of ototoxicity. ADULTS Adults may be taking diuretics for prolonged periods and need to be aware of the signs and symptoms of fluid imbalance to report to their healthcare provider. Adults receiving chronic diuretic therapy should weigh themselves on the same scale, in the same clothes, and at the same time each day to monitor for fluid retention or sudden fluid loss.They should be alerted to situations that could aggravate fluid loss, such as diarrhoea, vomiting, or excessive heat and sweating, which could change their need for the diuretic.They should also be urged to maintain their fluid intake to help balance their body’s compensatory mechanisms and to prevent fluid rebound.

Diuretics are often used in children to treat oedema associated with heart defects, to control hypertension, and to treat oedema associated with renal and pulmonary disorders. Hydrochlorothiazide has established paediatric dosing guidelines. Frusemide is often used when a stronger diuretic is needed; care should be taken not to exceed 6 mg/kg per day when using this drug. Ethacrynic acid may be used orally in some situations but should not be used in infants. Bumetanide, although not recommended for use in children, may be used for children who are taking other ototoxic drugs, including antibiotics, and may cause less hypokalaemia, making it preferable to frusemide for children also taking digoxin. Spironolactone is the only potassium-sparing diuretic that is recommended for use in children, but, as with adults, it should not be used in the presence of severe renal impairment.