valsartan

valsartan

(val sar' tan)

Diovan

Pregnancy Category C (first trimester)

Pregnancy Category D (second and third trimesters)

Drug classes

Angiotensin II receptor blocker

Antihypertensive

Therapeutic actions

Selectively blocks the binding of angiotensin II to specific tissue receptors found in the vascular smooth muscle and adrenal gland; this action blocks thevasoconstricting effect of the renin–angiotensin system as well as the release of aldosterone, leading to decreased BP; may prevent the vessel remodeling associated with the development of atherosclerosis.

Indications

·        Treatment of hypertension, alone or in combination with other antihypertensives

·        Treatment of heart failure in patients who are intolerant of ACE inhibitors

Contraindications and cautions

·        Contraindicated with hypersensitivity to valsartan, pregnancy (use during second or third trimester can cause injury or even death to fetus), lactation.

·        Use cautiously with hepatic or renal dysfunction, hypovolemia.

Available forms

Tablets—40, 80, 160, 320 mg

Dosages

ADULTS

·        Hypertension: 80 mg PO daily; range 80–320 mg/day.

·        Heart failure: Starting dose is 40 mg bid, titration to 80 mg and 160 mg bid should be done to the highest dose, as tolerated by the patient. Maximum daily dose is 320 mg daily given in divided doses. Concomitant use with an ACE inhibitor and a beta blocker is not recommended.

·        Post-MI left ventricular dysfunction: Start as early as 12 hr post-MI; 20 mg PO bid, may increase after 7 days to 40 mg PO bid; titrate to 160 mg PO bid if tolerated.

PEDIATRIC PATIENTS

Safety and efficacy not established.

PATIENTS WITH HEPATIC OR RENAL IMPAIRMENT

Exercise caution and monitor patient frequently.

Pharmacokinetics

Route	Onset	Peak
Oral	Varies	2–4 hr

Metabolism: Hepatic; T_1/2: 6 hr

Distribution: Crosses placenta; enters breast milk

Excretion: Feces and urine

Adverse effects

·        CNS: Headache, dizziness, syncope, muscle weakness

·        CV: Hypotension

·        Dermatologic: Rash, inflammation, urticaria, pruritus, alopecia, dry skin

·        GI: Diarrhea, abdominal pain, nausea, constipation, dry mouth, dental pain

·        Respiratory: URI symptoms, cough, sinus disorders

·        Other: Cancer in preclinical studies, back pain, fever, gout, hyperkalemia

Nursing considerations

Assessment

·        History: Hypersensitivity to valsartan; pregnancy, lactation; hepatic or renal dysfunction; hypovolemia

·        Physical: Skin lesions, turgor; T; reflexes, affect; BP; R, respiratory auscultation; LFTs, renal function tests

Interventions

·        Administer without regard to meals.

·        WARNING: Ensure that patient is not pregnant before beginning therapy; suggest using barrier birth control while using drug; fetal injury and deaths have been reported.

·        Find alternative method of feeding infant if drug is being given to nursing mother. Depression of renin–angiotensin system in infants is potentially very dangerous.

·        WARNING: Alert surgeon and mark patient's chart that valsartan is being given. Blockage of renin–angiotensin system following surgery can produce problems. Hypotension may be reversed with volume expansion.

·        Monitor patient closely in any situation that may lead to decrease in BP secondary to reduction in fluid volume—excessive perspiration, dehydration, vomiting, diarrhea—as excessive hypotension can occur.

Teaching points

·        Take this drug without regard to meals. Do not stop taking drug without consulting your health care provider.

·        Use a barrier method of birth control while using this drug; if you become pregnant or desire to become pregnant, consult your health care provider.

·        You may experience these side effects: Dizziness (avoid driving or performing hazardous tasks); headache (medications may be available to help); nausea, vomiting, diarrhea (proper nutrition is important; consult a dietitian); symptoms of upper respiratory tract infection, cough (do not self-medicate; consult your health care provider if this becomes uncomfortable).

·        Report fever, chills, dizziness, pregnancy.

Adverse effects in Italic are most common; those in Bold are life-threatening.