ADMINISTRATION ROUTES:
PO, NG
ALTERNATIVE NAMES:
Cozaar, Hyzaar (contains losartan and hydrochlorothiazide)
ICU INDICATIONS:
- Hypertension
- Heart failure
PRESENTATION AND ADMINISTRATION:
PO / NG:
Tablets:
Hyzaar: 50 mg losartan, 12.5 mg hydrochlorothiazide (yellow)
Cozaar: 12.5mg tablets (blue), 25mg (white), 50 mg (white), 100 mg (white)
Note: tablets can be crushed for administration down NG tubes
DOSAGE:
PO / NG:
12.5 mg OD
Increase to maxmimum 100 mg/day
DOSAGE IN RENAL FAILURE AND RENAL REPLACEMENT THERAPY:
Start with small dose and increase cautiously
DOSAGE IN PAEDIATRICS:
PO / NG:
0.5 - 2 mg/kg OD
CLINICAL PHARMACOLOGY:
Losartan potassium is an angiotensin II receptor (type AT1) antagonist
CONTRAINDICATIONS:
- Hypersensitivity to losartan
WARNINGS:
Volume-deplete patients
In patients who are intravascularly volume-depleted (especially those treated with diuretics), symptomatic hypotension may occur after initiation of therapy with losartan
PRECAUTIONS:
General:
Impaired Hepatic Function
Based on pharmacokinetic data which demonstrate significantly increased plasma concentrations of losartan in cirrhotic patients, a lower dose should be considered for patients with impaired liver function
Impaired Renal Function
In patients whose renal function may depend on the activity of the renin-angiotensin- aldosterone system (e.g., patients with severe congestive heart failure), treatment with angiotensin converting enzyme inhibitors has been associated with oliguria and/or progressive azotaemia and (rarely) with acute renal failure and/or death. Similar outcomes have been reported with losartan potassium. In studies of ACE inhibitors in patients with unilateral or bilateral renal artery stenosis, increases in serum creatinine or BUN have been reported. Similar effects have been reported with losartan potassium; in some patients, these effects were reversible upon discontinuation of therapy. Electrolyte Imbalance
Electrolyte imbalances are common in patients with renal impairment, with or without diabetes, and should be addressed. In a clinical study conducted in Type 2 diabetic patients with proteinuria, the incidence of hyperkalaemia was higher in the group treated with losartan potassium as compared to the placebo group; however, few patients discontinued therapy due to hyperkalaemia.
Laboratory Tests:
No tests are indicated in addition to routine ICU tests
Drug/Laboratory Test Interactions:
None known
IMPORTANT DRUG INTERACTIONS IN ICU:
As with other drugs that block angiotensin II or its effects, concomitant use of potassium-sparing diuretics (e.g., spironolactone, triamterene, amiloride), potassium supplements, or salt substitutes containing potassium may lead to increases in serum potassium.
ADVERSE REACTIONS:
Body as a whole:
Angiooedema, fatigue, anaphylaxis
Musculoskeletal:
Cramp, back pain, rhabdomylosis
Cardiovascular:
Hypotension
Metabolic:
Hyperkalaemia, hyponatraemia
Gastrointestinal:
Hepatitis
Urogenital:
Renal failure