LosartanNursing considerations

Side effects by what to assess

Sources: [1][2][3][4][5][6]

Blood pressure

Why

Response and hypotension

When

After starting and during titration, especially with diuretics

Act on

Correct volume or salt depletion; start at 25 mg if volume depleted

Normal

Below 120/80 mm Hg.

Sources: [1][2][3]

Potassium

Why

Hyperkalemia

When

Periodically, and when other potassium-raising drugs are used

Act on

Hyperkalemia may require a dose cut or stopping losartan

Normal

3.7 to 5.2 mEq/L.

Sources: [1][2][3]

Serum creatinine

Why

Renal function decline

When

Periodically in at-risk patients such as renal artery stenosis, CKD, severe heart failure, volume depletion, or NSAID use

Act on

Consider holding or stopping with a clinically significant drop in renal function

Normal

0.7 to 1.3 mg/dL in men and 0.5 to 0.95 mg/dL in women.

Sources: [1][2][3]

High-alert status

ARBs are not on the ISMP acute care high-alert list.

Sources: [1]

Narrow therapeutic index

The label does not describe a narrow therapeutic index or direct dosing by measured blood levels of the drug.

Sources: [1]

Boxed warning

Fetal toxicity. Drugs acting on the renin-angiotensin system can injure or kill the developing fetus. Stop losartan as soon as pregnancy is detected.

Sources: [1]

Antidote or reversal

No antidote. Overdose most likely causes hypotension and tachycardia, or bradycardia from vagal stimulation. Give supportive care for symptomatic hypotension. Hemodialysis does not remove losartan or its active metabolite.

Sources: [1]

Patient teaching

• Women who could become pregnant should know the fetal risks and report a pregnancy right away
• Do not use potassium supplements or potassium salt substitutes without asking the prescriber
• Rise slowly from lying or sitting to avoid dizziness and fainting
• Vomiting, diarrhea, heavy sweating, or poor fluid intake can drop blood pressure; tell the prescriber
• Keep taking it even when feeling well; full effect may take 3 to 6 weeks
• Seek care right away for swelling of the face, lips, tongue, or throat

Sources: [1][2][3][4]

Sound-alike and look-alike names

• Cozaar and Zocor
• Cozaar and Colace

Sources: [1]

Adult dose

Hypertension

50 mg once daily to start; may increase to a maximum of 100 mg once daily. Start at 25 mg if volume depleted.

Hypertension with left ventricular hypertrophy

50 mg once daily. Add hydrochlorothiazide 12.5 mg and/or raise losartan to 100 mg, then raise hydrochlorothiazide to 25 mg, based on blood pressure response.

Diabetic nephropathy (type 2 diabetes)

50 mg once daily; increase to 100 mg once daily based on blood pressure response.

Sources: [1][2][3]

Renal adjustment

No dose change needed for renal impairment unless the patient is also volume depleted. Monitor renal function in patients whose kidneys depend on the renin-angiotensin system, such as renal artery stenosis or severe heart failure.

Sources: [1][2]

Hepatic adjustment

Mild to moderate hepatic impairment: start at 25 mg once daily, since levels of losartan and its metabolite rise. Not studied in severe hepatic impairment.

Sources: [1][2]

Mechanism

Losartan and its active metabolite block angiotensin II from binding the AT1 receptor in blood vessels and the adrenal gland. This prevents angiotensin II from constricting vessels and releasing aldosterone. Unlike ACE inhibitors, it does not inhibit ACE, so bradykinin is not built up.

Sources: [1]