losartan potassium
Cozaar
Pregnancy Risk Category C (D in second and third trimesters)
How supplied
Tablets: 25 mg, 50 mg
Action
An angiotensin II receptor antagonist that inhibits the vasoconstricting and
aldosterone-secreting effects of angiotensin II by selectively blocking the binding of angiotensin II to its receptor sites that are found in many tissues, including vascular smooth muscle and adrenal glands.
Indications & dosage
Hypertension--
Adults: initially, 25 to 50 mg P.O. daily. Maximum daily dose is 100 mg in one or two divided doses.
Adjust-a-dose: For patients with impaired hepatic function and in those who are intravascularly volume-depleted (such as those receiving diuretics), use lowest dosage (25 mg) initially.
Adverse reactions
CNS: dizziness, insomnia.
EENT: nasal congestion, sinusitis.
GI: diarrhea, dyspepsia.
Musculoskeletal: muscle cramps, myalgia, back or leg pain.
Respiratory: cough, upper respiratory tract infection.
Interactions
Drug-drug. Potassium-sparing diuretics, potassium supplements: possible hyperkalemia. Monitor closely.
Drug-food. Salt substitutes containing potassium: risk of hyperkalemia. Monitor closely.
Effects on diagnostic tests
None reported.
Contraindications
Contraindicated in patients with hypersensitivity to drug.
Nursing considerations
- Breast-feeding isn't recommended during losartan therapy.
- Use cautiously in patients with impaired renal or hepatic function.
- Drugs that act directly on the renin-angiotensin system (such as losartan) can cause fetal and neonatal morbidity and death when given to pregnant women. These problems have not been detected when exposure has been limited to the first trimester. If pregnancy is suspected, notify doctor because drug should be discontinued.
- Drug can be used alone or with other antihypertensives.
- If antihypertensive effect measured by the serum trough level of drug, using once-daily dosing, is inadequate, a b.i.d. regimen using the same total daily dose or an increase in dose may give a more satisfactory response.
- Monitor patient's blood pressure closely to evaluate effectiveness of therapy. When losartan is used alone, the effect on blood pressure is notably less in black patients than in patients of other races.
- Monitor patients who are also taking diuretics for symptomatic hypotension.
- Regularly assess the patient's renal function (via serum creatinine and BUN levels), as ordered.
- Patients with severe heart failure whose renal function depends on the angiotensin-aldosterone system have experienced acute renal failure during ACE inhibitor therapy. Manufacturer of losartan states that drug would be expected to have the same effect. Closely monitor patient, especially during first few weeks of therapy.
- Alert:
Don't confuse Cozaar with Zocor.
Patient teaching
- Tell patient to avoid salt substitutes; these products may contain potassium, which can cause hyperkalemia in patients taking losartan.
- Inform woman of childbearing age about consequences of second- and third-trimester exposure to drug; instruct her to notify doctor immediately if pregnancy is suspected.
*Liquid contains alcohol. **May contain tartrazine. †Canada ‡Australia §U.K. OTCOver the counter
Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE-THREATENING