ADMINISTRATION ROUTES:
PO, IV
ALTERNATIVE NAMES:
Diurin, Lasix, Frusemide, Furosemide
ICU INDICATIONS:
- Fluid retention manifesting as pulmonary or peripheral oedema
- Hyperkalaemia
PRESENTATION AND ADMINISTRATION:
PO:
Tablets:
Diurin 40 mg tablets (off white), Diurin 500 mg tablets (off white)
Oral Solution:
Lasix oral solution 10 mg/mL
IV:
IV formulations available are:
- Frusemide injection 20 mg/2 mL solution
- Lasix high dose infusion 250 mg in 25 mL with 1000 mg of mannitol as a stabilising agent
Administer doses of up to 80 mg by slow IV injection over 2-5 minutes
For infusion doses of up to 5 mg/hr use low dose infusion mixture of 40 mg in 40 mL of compatible IV fluid. For infusion doses of greater than 5 mg/hr use high dose infusion mixture with undiluted Lasix high dose infusion (i.e 250 mg in 25 mL or 500 mg in 50 mL)
Rate of infusion should not exceed 4 mg/min
Compatible with the following IV fluids:
Normal saline, Hartmanns
Note: Glucose solutions are unsuitable
Store at room temperature
Protect from light
Dilutions in compatible IV fluid are stable for 24 hours at room temperature – discard if not used within 24 hours. Do not use if solutions have a yellow colour or contain crystal deposits
DOSAGE:
PO:
10 mg OD to 80 mg TDS
IV:
Dosage is highly individualised
Bolus dosing:
5 mg may be sufficient to cause significant diuresis if frusemide naïve
Otherwise 20-80 mg QID to TDS
Infusion dosing:
Up to 100 mg/hr by infusion may be required if significant renal impairment
DOSAGE IN RENAL FAILURE AND RENAL REPLACEMENT THERAPY:
Dose in renal impairment
| GFR (ml/min) | DOSE |
|---|---|
| <10 | dose as in normal renal function; increased doses may be required |
| 10-20 | dose as in normal renal function |
| >20-50 | dose as in normal renal function |
Dose in renal replacement therapy
| MODALITY | DOSE |
|---|---|
| CAPD | not indicated |
| HD | not indicated |
| CVVHDF | rarely indicated; increased doses may be required |
DOSAGE IN PAEDIATRICS:
IV / PO:
Bolus dosing:
0.5 - 1 mg/kg QID, or up to 4 hourly
Infusion dosing:
50 mg/kg in 50 mL of Normal saline at 0.1 - 1 mg/kg/hr (0.1 - 1 mL/hr)
CLINICAL PHARMACOLOGY:
Frusemide is a potent diuretic that inhibits the absorption of sodium and chloride in the proximal and distal tubules and the loop of Henle.
CONTRAINDICATIONS:
- Known hypersensitivity to frusemide
WARNINGS:
Allergy to Sulfur drugs
Patients allergic to sulfonamides may also be allergic to frusemide
Ototoxicity
Cases of tinnitus and reversible or irreversible hearing impairment have been reported. Usually, reports indicate that frusemide ototoxicity is associated with rapid injection, severe renal impairment, doses exceeding several times the usual recommended dose, or concomitant therapy with aminoglycoside antibiotics or other ototoxic drugs.
PRECAUTIONS:
General:
Excessive diuresis may cause dehydration and blood volume reduction with circulatory collapse .
As with any effective diuretic, electrolyte depletion may occur during frusemide therapy, especially in patients receiving higher doses and a restricted salt intake. Hypokalaemia may develop with frusemide, especially with brisk diuresis, inadequate oral electrolyte intake, when cirrhosis is present, or during concomitant use of corticosteroids or ACTH. Digitalis therapy may exaggerate metabolic effects of hypokalaemia, especially myocardial effects.
Asymptomatic hyperuricaemia can occur and gout may rarely be precipitated.
Laboratory Tests:
No tests in addition to routine ICU tests are required
Drug/Laboratory Test Interactions:
None noted
IMPORTANT DRUG INTERACTIONS IN ICU:
Frusemide may increase the ototoxic potential of aminoglycoside antibiotics, especially in the presence of impaired renal function. Except in life-threatening situations, avoid this combination.
Lithium generally should not be given with diuretics because they reduce lithium's renal clearance and increase the risk of lithium toxicity.
ADVERSE REACTIONS:
Gastrointestinal System:
Pancreatitis, jaundice (intrahepatic cholestatic jaundice), anorexia, oral and gastric irritation, cramping, diarrhoea, constipation, nausea, and vomiting
Systemic Hypersensitivity:
Systemic vasculitis, interstitial nephritis, and necrotising angiitis
Central Nervous System:
Tinnitus and hearing loss, paraesthesias, vertigo, dizziness, headache, blurred vision, and xanthopsia
Haematologic:
Aplastic anaemia (rare), thrombocytopaenia, agranulocytosis (rare), haemolytic anaemia, leukopaenia, and anaemia
Dermatologic-Hypersensitivity:
Exfoliative dermatitis, erythema multiforme, purpura, photosensitivity, urticaria, rash, and pruritus
Cardiovascular:
Orthostatic hypotension may occur and be aggravated by alcohol, barbiturates or narcotics
Other:
Hyperglycaemia, glycosuria, hyperuricaemia, muscle spasm, weaknesses, restlessness, urinary bladder spasm, thrombophlebitis, and fever